-
Question 1
Correct
-
Which of the following will be affected by a lesion in the posterior column-medial lemniscus system?
Your Answer: Fine touch
Explanation:The posterior column–medial lemniscus (PCML) pathway is a sensory pathway that transmits fine touch and conscious proprioceptive information from the body to the brain. As the posterior columns are also known as dorsal columns, the pathway is also called the dorsal column–medial lemniscus system or DCML.
-
This question is part of the following fields:
- Neurology
- Physiology
-
-
Question 2
Correct
-
The nutcracker effect of the alimentary canal is described as a nutcracker-like compression caused by the aorta and the superior mesenteric arteries on a certain section of the alimentary canal leading to bowel obstruction. Which of the following parts of the alimentary canal is usually obstructed by this nutcracker compression of the two arteries?
Your Answer: Duodenum
Explanation:The ‘nutcracker effect’ is only seen in one part of the alimentary canal, and that is in the third part of the duodenum. This can happen when the superior mesenteric artery that passes across the duodenum and the aorta, posteriorly to the third part of the duodenum enlarges and starts compressing the duodenum. The result is an obstructed duodenum that inhibits passage of food.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 3
Incorrect
-
What causes a reduction in pulmonary functional residual capacity?
Your Answer: Emphysema
Correct Answer: Pulmonary fibrosis
Explanation:Pulmonary functional residual capacity (FRC) is = volume of air present in the lungs at the end of passive expiration.
Obstructive diseases (e.g. emphysema, chronic bronchitis, asthma) = an increase in FRC due to an increase in lung compliance and air trapping.
Restrictive diseases (e.g. pulmonary fibrosis) result in stiffer, less compliant lungs and a reduction in FRC.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 4
Incorrect
-
Which among the following vertebrae marks the lowest extent of the superior mediastinum?
Your Answer: Seventh cervical
Correct Answer: Fourth thoracic
Explanation:The superior mediastinum lies between the manubrium anteriorly and the upper vertebrae of the thorax posteriorly. Below, it is bound by a slightly oblique plane that passes backward from the sternal angle to the lower part of the body of T4 and laterally by the pleura.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 5
Incorrect
-
Congenital anomalies of genitourinary tract are more common than any other system. Which of the following anomalies carries the greatest risk of morbidity?
Your Answer: Medullary sponge kidney
Correct Answer: Bladder exstrophy
Explanation:Bladder exstrophy is the condition where the urinary bladder opens from the anterior aspect suprapubically. The mucosa of the bladder is continuous with the abdominal skin and there is separation of the pubic bones. The function of the upper urinary tract remains normal usually. Treatment consists of surgical reconstruction of the bladder and returning it to the pelvis. There can be a need for continent urinary diversion along with reconstruction of the genitals.
-
This question is part of the following fields:
- Pathology
- Renal
-
-
Question 6
Incorrect
-
what is the cause of a prolonged PT(prothrombin time)?
Your Answer: von Willebrand factor deficiency
Correct Answer: Liver disease
Explanation:PT measure the intrinsic pathway of coagulation. It determines the measure of the warfarin dose regime, liver disease and vit K deficiency status along with the clotting tendency of blood. PT measured factors are II,V,VII,X and fibrinogen. It is used along with aPTT which measure the intrinsic pathway.
-
This question is part of the following fields:
- General
- Physiology
-
-
Question 7
Incorrect
-
A mechanic sustained a deep laceration to his right cubital fossa which resulted in him unable to move the proximal radioulnar joint of his right arm. Which muscles was affected?
Your Answer: Extensor carpi ulnaris
Correct Answer: Pronator teres
Explanation:The correct answer is the pronator teres muscle. This muscle arises from 2 heads of origin: the humerus and ulnar. Between the 2 heads is the site of entrance of median nerve to the forearm. This muscle acts on the proximal radio-ulnar joint to rotate the radius on the ulna, otherwise known as pronation. It also assists in forearm flexion if the radius is fixed.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 8
Incorrect
-
Which of the following abnormalities can be seen in patients with hypermagnesemia?
Your Answer: Tetany
Correct Answer: Respiratory depression
Explanation:Hypermagnesemia is an electrolyte disturbance in which there is a high level of magnesium in the blood. It is defined as a level greater than 1.1 mmol/L. Symptoms include weakness, confusion, decreased breathing rate, and cardiac arrest.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
-
-
Question 9
Correct
-
Glucose is the most important source of energy for cellular respiration. The transport of glucose in the renal tubular cells occurs via:
Your Answer: Secondary active transport with sodium
Explanation:In 1960, Robert K. Crane presented for the first time his discovery of the sodium-glucose cotransport as the mechanism for glucose absorption. Glucose transport through biological membranes requires specific transport proteins. Transport of glucose through the apical membrane of renal tubular as well as intestinal epithelial cells depends on the presence of secondary active Na+–glucose symporters, SGLT-1 and SGLT-2, which concentrate glucose inside the cells, using the energy provided by co-transport of Na+ ions down their electrochemical gradient.
-
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 10
Incorrect
-
The superior pancreaticoduodenal artery, the artery that supplies blood to the pancreas and the duodenum, is a branch of the:
Your Answer: Splenic artery
Correct Answer: Gastroduodenal artery
Explanation:The superior pancreaticoduodenal artery together with the right gastroepiploic artery form the two branches of the gastroduodenal artery which divides at the lower border of the duodenum.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 11
Correct
-
A 50-year old lady presented to the clinic with chronic pain in the abdomen. On physical examination, she was found to be pale. Further investigations revealed a decrease in both serum iron and total iron-binding capacity, along with an increase in serum ferritin. These findings are seen in:
Your Answer: Anaemia of chronic disease
Explanation:Anaemia of chronic disease is characterized by low serum iron, iron-binding capacity and saturation with increased ferritin (storage iron). Haemolytic anaemia is characterized by normal iron levels as the haemoglobin released from the haemolysed red blood cells is recycled. Anaemia due to chronic blood loss leads to low serum iron, low ferritin and high total iron-binding capacity (TIBC). Malabsorption, especially with duodenal involvement can also lead to iron deficiency anaemia with low ferritin and high TIBC. Megaloblastic anaemia due to vitamin B12 and folate deficiency is not associated with abnormalities in metabolism of iron.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 12
Incorrect
-
Which of the following foramen provides passage of the facial nerve?
Your Answer: Foramen ovale
Correct Answer: Internal acoustic meatus
Explanation:The internal auditory meatus provides a passage through which the vestibulocochlear nerve, the facial nerve, and the labyrinthine artery (an internal auditory branch of the basilar artery) can pass from inside the skull to structures of the inner ear and face.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 13
Incorrect
-
Which of the following is the source of blood supply to the artery of the round ligament at the head of the femur?
Your Answer: Superior gluteal artery
Correct Answer: Obturator artery
Explanation:The posterior branch of the obturator artery provides an articular branch to the head of the femur.
-
This question is part of the following fields:
- Anatomy
- Lower Limb
-
-
Question 14
Incorrect
-
A premenopausal woman has an ovarian tumour. Which is the most common benign germ-cell tumour that could occur in a premenopausal woman?
Your Answer: Mucinous cystadenoma
Correct Answer: Dermoid cyst
Explanation:A dermoid cyst is a teratoma of a cystic nature that contains an array of developmentally mature and solid tissues. Dermoid cysts grow slowly and this type of cystic teratoma is nearly always benign.
-
This question is part of the following fields:
- Neoplasia
- Pathology
-
-
Question 15
Incorrect
-
From which branchial (pharyngeal) pouch does the inferior parathyroid gland arise?
Your Answer: 1st
Correct Answer: 3rd
Explanation:The following structures arise from each branchial pouch:
1st pouch – eustachian tube, middle ear, mastoid, and inner layer of the tympanic membrane
2nd pouch – middle ear, palatine tonsils
3rd pouch – inferior parathyroid glands, thymus
4th pouch – superior parathyroid glands, ultimobranchial body which forms the parafollicular C-cells of the thyroid gland, musculature and cartilage of larynx (along with the sixth pharyngeal pouch)
5th pouch – rudimentary structure
6th pouch – along with the fourth pouch, contributes to the formation of the musculature and cartilage of the larynx.
-
This question is part of the following fields:
- Anatomy
- Endocrine; Embryology
-
-
Question 16
Incorrect
-
A 45 -year-old female is recently diagnosed with breast cancer. She has a 8-cm-diameter mass in her left breast, with enlarged left axillary node. What is the most likely stage of her disease?
Your Answer: IIB
Correct Answer: IIIA
Explanation:Stage IIIA breast cancer is T0–2 N2 M0 or T3 N1-2 M0 disease. It describes invasive breast cancer in which either: the tumour is smaller than 5 cm in diameter and has spread to 4 to 9 axillary lymph nodes; or it is found through imaging studies or clinical exam to have spread to internal mammary nodes (near the breastbone found during imaging tests or a physical exam); or the tumour is larger than 5 cm and has spread to 1 to 9 axillary nodes, or to internal mammary nodes. In this stage, the cancer has not metastasized (spread to distant sites).
-
This question is part of the following fields:
- Neoplasia
- Pathology
-
-
Question 17
Correct
-
An 80 year-old lady presents to the out patient clinic complaining of chest pain of 2 months' duration with a normal electrocardiogram and cardiac enzymes. A computed tomographic scan is done which reveals a mass lesion involving a structure in the middle mediastinum. Which among the following structures could be involved?
Your Answer: Ascending aorta
Explanation:The middle mediastinum is the broadest part of the mediastinal cavity containing the heart enclosed in the pericardium, ascending aorta, lower half of the superior vena cava with the azygos vein opening into it, the bifurcation of the trachea and the two bronchi, the pulmonary artery with its branches, pulmonary veins, phrenic nerves and bronchial lymph nodes. The most likely structure involved is the ascending aorta, perhaps with an aneurysm.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 18
Incorrect
-
A 40-year old woman presents with tightening of the skin over her fingers which makes movement of her fingers difficult.. She also gives a history of her fingers turning blue on exposure to low temperatures. She admits to gradual weight loss. Investigations reveal negative rheumatoid factor, negative antinuclear antibody and a positive anticentromere body. Which of the following conditions is she likely to have?
Your Answer: Zollinger-Ellison syndrome
Correct Answer: Oesophageal stricture
Explanation:Scleroderma is a connective tissue disorder that ranges in severity and progression. The disease could show generalised skin thickening with rapid, fatal, visceral involvement; or only cutaneous involvement (typically fingers and face). The slow progressive form is also known as ‘limited cutaneous scleroderma’ or CREST syndrome (calcinosis cutis, Raynaud’s phenomenon, (o)oesophageal dysmotility, sclerodactyly, and telangiectasia).
-
This question is part of the following fields:
- Gastrointestinal; Hepatobiliary
- Pathology
-
-
Question 19
Incorrect
-
A 15-day old male baby was brought to the emergency department with sweating and his lips turning blue while feeding. He was born full term. On examination, his temperature was 37.9°C, blood pressure 75/45 mmHg, pulse was 175/min, and respiratory rate was 42/min. A harsh systolic ejection murmur could be heard at the left upper sternal border. X-ray chest showed small, boot-shaped heart with decreased pulmonary vascular markings. He most likely has:
Your Answer: Anomalous left coronary artery
Correct Answer: Tetralogy of Fallot
Explanation:The most common congenital cyanotic heart disease and the most common cause of blue baby syndrome, Tetralogy of Fallot shows four cardiac malformations occurring together. These are ventricular septal defect (VSD), pulmonary stenosis (right ventricular outflow obstruction), overriding aorta (degree of which is variable), and right ventricular hypertrophy. The primary determinant of severity of disease is the degree of pulmonary stenosis. Tetralogy of Fallot is seen in 3-6 per 10,000 births and is responsible for 5-7% congenital heart defects, with slightly higher incidence in males. It has also been associated with chromosome 22 deletions and DiGeorge syndrome. It gives rise to right-to-left shunt leading to poor oxygenation of blood. Primary symptom is low oxygen saturation in the blood with or without cyanosis at birth of within first year of life. Affected children ay develop acute severe cyanosis or ‘tet spells’ (sudden, marked increase in cyanosis, with syncope, and may result in hypoxic brain injury and death). Other symptoms include heart murmur, failure to gain weight, poor development, clubbing, dyspnoea on exertion and polycythaemia. Chest X-ray reveals characteristic coeur-en-sabot (boot-shaped) appearance of the heart. Treatment consists of immediate care for cyanotic spells and Blalock–Taussig shunt (BT shunt) followed by corrective surgery.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 20
Incorrect
-
Which of the following associations is correctly matched with the body's defence mechanism in fighting infection?
Your Answer: Non-specific humoral mechanism → T lymphocytes
Correct Answer: Specific cellular mechanism → cytotoxic T cells
Explanation:The immune system has certain levels of defence against pathogens. First line includes simple barriers such as skin, mucosa and stomach acid that prevent the pathogen from entering into the body. If this barrier is breached then the innate immune system is activated which includes leukocytes (macrophages, neutrophils, mast cells, eosinophils, basophils, natural killer cells). If the pathogens invade the second layer of defence then the third layer, adaptive immunity is activated, which includes B and T lymphocytes. B cells provide a humoral response whereas cytotoxic T cells have specific cellular mechanisms. They maintain a memory of past infections and are activated faster following a recurrence.
-
This question is part of the following fields:
- General
- Physiology
-
-
Question 21
Incorrect
-
Which of the following malignancies is likely to have the best prognosis?
Your Answer: Anaplastic carcinoma of the thyroid
Correct Answer: Papillary carcinoma of the thyroid
Explanation:Papillary carcinoma accounts for 70-80% of all thyroid cancers and is seen commonly in people aged 30-60 years. It is more aggressive in elderly patients. 10-20% cases may have recurrence or persistent disease. More common in females with a female to male ratio of 3:1. Papillary carcinomas can also contain follicular carcinomas. The common route of spread is through lymphatics to regional nodes in one-third cases and pulmonary metastasis can also occur. Papillary carcinomas of the thyroid have the best prognosis, especially in patients less than 45 years of age with small tumours confined to the thyroid gland.
-
This question is part of the following fields:
- Endocrine
- Pathology
-
-
Question 22
Correct
-
A 55-year-old male has a mass on the right lung with involvement of the right mediastinal lymph nodes. What is the nodal staging according to the TNM staging?
Your Answer: N2
Explanation:The N stages for lung cancer are from NO to N3 : NO, there is no lung cancer in any lymph nodes: N1, there is lung cancer in the proximal lymph nodes: N2, there is lung cancer in the mediastinal hilar lymph nodes, but on the same side as the affected lung or there is lung cancer in the carinal lymph nodes: N3, there is metastatic lung cancer in lymph nodes on the opposite side of the chest, in the cervical or apical lymph nodes. In this patient the ipsilateral mediastinal node is involved, thus it is classified as N2.
-
This question is part of the following fields:
- Neoplasia
- Pathology
-
-
Question 23
Incorrect
-
Which of the following variables are needed to calculate inspiratory reserve volume of a patient?
Your Answer: Tidal volume and expiratory reserve volume
Correct Answer: Tidal volume, vital capacity and expiratory reserve volume
Explanation:Vital capacity = inspiratory reserve volume + tidal volume + expiratory reserve volume. Thus, inspiratory reserve volume can be calculated if tidal volume, vital capacity and expiratory reserve volume are known.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 24
Incorrect
-
A 23-year-old woman decides to donate a kidney through a kidney chain. Which of the following indices would be expected to be decreased in the donor after full recovery from the operation?
Your Answer: Creatinine production
Correct Answer: Creatinine clearance
Explanation:Since medication to prevent rejection is so effective, donors do not need to be similar to their recipient. Most donated kidneys come from deceased donors; however, the utilisation of living donors is on the rise. Most problems encountered with live donation are associated with the donor. Firstly, there are the potentially harmful investigative procedures carried out in the assessment phase, the most hazardous being renal angiography, where there is cannulation of the artery and injection of a radio-opaque dye to determine the blood supply to the kidney. Secondly, there are the short-term risks of nephrectomy surgery. According to the literature, there is a mortality rate of between 1 in 1600 and 1 in 3000, but this is no more than is associated with any anaesthetic. In the initial postoperative period creatinine clearance may be decreased but this recovers fully over a few weeks to months. Long-term complications include prolonged wound pain.
-
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 25
Incorrect
-
The oesophagus is an important part of the alimentary canal. It receives blood from various arteries in the body. Which one of the following is an artery that will lead to some level of ischaemia to the oesophagus when ligated?
Your Answer: Inferior mesenteric
Correct Answer: Left inferior phrenic
Explanation:The oesophagus receives its blood supply from the following arteries: the inferior thyroid branch of the thyrocervical trunk, the descending thoracic aorta, the left gastric branch of the coeliac artery and the from the left inferior phrenic artery of the abdominal aorta. Hence ligation of the left inferior phrenic will lead to ischemia to some portions of the oesophagus.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 26
Correct
-
Which of the following will show decreased hearing when tested by air conduction but normal hearing when tested by bone conduction?
Your Answer: Fibrosis causing fixation of the ossicles
Explanation:As the cochlea is embedded into bone, the vibrations from the bone are transmitted directly to the fluid in the cochlea. Hence, any damage to the ossicles or tympanic membrane will not show an abnormal result on bone conduction test.
-
This question is part of the following fields:
- Neurology
- Physiology
-
-
Question 27
Incorrect
-
A medical student is asked to calculate the net pressure difference in a capillary wall, considering: Interstitial fluid hydrostatic pressure = –3 mmHg, Plasma colloid osmotic pressure = 28 mmHg, Capillary hydrostatic pressure = 17 mmHg, Interstitial fluid colloid osmotic pressure = 8 mmHg, and Filtration coefficient = 1. Which is the correct answer?
Your Answer: +3 mmHg
Correct Answer: 0 mmHg
Explanation:The rate of filtration at any point along a capillary depends on a balance of forces sometimes called Starling’s forces after the physiologist who first described their operation in detail. The Starling principle of fluid exchange is key to understanding how plasma fluid (solvent) within the bloodstream (intravascular fluid) moves to the space outside the bloodstream (extravascular space). Fluid movement = k[(pc– pi)–(Πc– Πi)] where k = capillary filtration coefficient, pc = capillary hydrostatic pressure, pi= interstitial hydrostatic pressure, Πc = capillary colloid osmotic pressure, Πi = interstitial colloid osmotic pressure. Therefore: 1 × [capillary hydrostatic pressure (17) – interstitial fluid hydrostatic pressure (–3)] – [plasma colloid osmotic pressure (28) – interstitial fluid colloid osmotic pressure (8)] = 0 mmHg
-
This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
-
-
Question 28
Incorrect
-
Purkinje fibres in the heart conduct action potentials at the rate of:
Your Answer: 18.5 - 22.0 m/s
Correct Answer: 1.5–4.0 m/s
Explanation:Purkinje fibres control the heart rate along with the sinoatrial node (SA node) and the atrioventricular node (AV node). The QRS complex is associated with the impulse passing through the Purkinje fibres. These fibres conduct action potential about six times faster than the velocity in normal cardiac muscle.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 29
Correct
-
All the following arteries contribute to the blood supply of the hip joint except:
Your Answer: Pudendal
Explanation:The blood supply to the hip joint is from two main arteries, the medial circumflex femoral and lateral circumflex femoral arteries. These are branches of the deep artery of the thigh, which itself is a branch of the femoral artery. There is contribution of blood supply from the inferior gluteals, foveal and obturator arteries.
-
This question is part of the following fields:
- Anatomy
- Lower Limb
-
-
Question 30
Incorrect
-
Which of the following is true about a patient who has undergone total colectomy and ileostomy?
Your Answer: This patient is at increased risk of anaemia due to malabsorption of both iron and vitamin B12
Correct Answer: Following total colectomy and ileostomy, the volume and water content of ileal discharge decreases over time
Explanation:After a patient has undergone total colectomy and ileostomy, the volume of ileal discharge, along with its water content gradually decreases over time. Post surgery, most patients can live a normal life. Iron and vitamin B12 absorption do not take place in the colon and hence are not affected significantly by a colectomy.
-
This question is part of the following fields:
- Gastroenterology
- Physiology
-
-
Question 31
Correct
-
How are amino acids transported across the luminal surface of the small intestinal epithelium?
Your Answer: Co-transport with sodium ions
Explanation:Once complex peptides are broken down into amino acids by the peptidases present in the brush border of small intestine, they are ready for absorption by at least four sodium-dependent amino acid co-transporters – one each for acidic, basic, neutral and amino acids, present on the luminal plasma membrane. These transporters first bind sodium and can then bind the amino acids. Thus, amino acid absorption is totally dependent on the electrochemical gradient of sodium across the epithelium. The basolateral membrane in contrast, possesses additional transporters to carry amino acids from the cell into the blood, but these are sodium-independent.
-
This question is part of the following fields:
- Gastroenterology
- Physiology
-
-
Question 32
Incorrect
-
You are asked to help a junior medical student studying anatomy to identify the left lung. Which of the following features found only in the left lung will you use the identify it?
Your Answer: Three lobes
Correct Answer: Cardiac notch
Explanation:Oblique fissure: is found on both the left and the right lungs. It separates the upper from the lower lobes in both lungs and the middle lobe from the lower lobe in the right lung(which has three lobes.)
The superior lobar bronchus is found in both lungs.
Cardiac notch: found only on the left lung.
Horizontal fissure: a deep groove separating the middle lobe from the upper lobe of the right lung is absent on the left lung.
Diaphragmatic surface: refers to the part of the lung, both the left and the right, that is in contact with the diaphragm.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 33
Incorrect
-
Post-total gastrectomy, there will be a decreased production of which of the following enzymes?
Your Answer: Amylase
Correct Answer: Pepsin
Explanation:Pepsin is a protease that is released from the gastric chief cells and acts to degrade proteins into peptides. Released as pepsinogen, it is activated by hydrochloric acid and into pepsin itself. Gastrin and the vagus nerve trigger the release of pepsinogen and HCl when a meal is ingested. Pepsin functions optimally in an acidic environment, especially at a pH of 2.
-
This question is part of the following fields:
- Gastroenterology
- Physiology
-
-
Question 34
Incorrect
-
What is the 5 year survival rate of a patient who is diagnosed with stage III colon cancer, who underwent successful resection and completed the prescribed session of adjuvant chemotherapy?
Your Answer: 70%–85%
Correct Answer: 30%–60%
Explanation:In this patient who has stage III colon cancer, the survival rate is 30-60%. For stage I or Dukes’ stage A disease, the 5-year survival rate after surgical resection exceeds 90%. For stage II or Dukes’ stage B disease, the 5-year survival rate is 70%–85% after resection, with or without adjuvant therapy. For stage III or Dukes’ stage C disease, the 5-year survival rate is 30%– 60% after resection and adjuvant chemotherapy and for stage IV or Dukes’ stage D disease, the 5-year survival rate is poor (approximately 5%).
-
This question is part of the following fields:
- Neoplasia
- Pathology
-
-
Question 35
Incorrect
-
During a surgical operation, whilst dissecting the mediastinal lymph nodes for a bronchogenic carcinoma of the right upper lobe bronchus, a patient's right sympathetic trunk is accidentally severed above the level of spinal nerve T1. Which function would be left intact in the affected region?
Your Answer: Arrector pili muscle activity
Correct Answer: Voluntary muscle activity
Explanation:The sympathetic nervous system regulates vascular tone, dilation of pupils, arrector pili muscles, sweat production and visceral reflexes. Neurones that supply the voluntary muscles originate from the ventral horn of the spinal cord. If these nerves were thus damaged, these functions would be impaired. The sympathetic nervous system is not responsible for voluntary muscle activity.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 36
Incorrect
-
A patient with Paget's disease of the bone is predisposed to developing which type of cancer?
Your Answer: Ewing’s sarcoma
Correct Answer: Osteosarcoma
Explanation:Paget’s disease of bone (PDB) is a focal disorder of bone. It is presumed benign in nature and mediated by abnormal osteoclast function. However osteosarcomas may occur in <1% of patients with Paget's disease of the bone. Osteosarcomas are osteogenic in origin, and consistently arise in sites of pagetic bone. This is not to be confused with Paget's disease of the breast.
-
This question is part of the following fields:
- Neoplasia
- Pathology
-
-
Question 37
Incorrect
-
A surgeon performing a laparoscopic repair of an inguinal hernia visualizes a loop of bowel protruding through the abdominal wall to form a direct inguinal hernia. When this is viewed from the side of the abdomen with a laparoscope, in which region would the hernial sac be?
Your Answer: Lateral inguinal fossa
Correct Answer: Medial inguinal fossa
Explanation:In a direct inguinal hernia, visceral contents exit the abdomen through a weak point in the fascia in the medial inguinal fossa i.e. the area between the medial and lateral umbilical folds. Such a hernia doesn’t pass through the deep inguinal ring or the lateral inguinal fossa. Note that direct hernias can go through the superficial inguinal ring, although rarely. The supravesical fossa, between the median and medial umbilical folds, is formed by a peritoneal reflection from the anterior abdominal wall onto the bladder and the retrovesical fossa is the region behind the urinary bladder.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 38
Correct
-
Which of the following changes in the histology of the cell is most likely to be accompanied by disruption of the cell membrane following an injury?
Your Answer: Coagulative necrosis
Explanation:The process of necrosis ends with the rupture of the cell membrane and the consequent release of the cellular components into the surrounding tissue. Apoptosis, pyknosis and karyorrhexis are not reversible events but the cell membrane remains intact. Cloudy swelling and hydropic changes are also reversible but again the cell membrane remains intact and they are therefore different and distinct from necrosis.
-
This question is part of the following fields:
- Cell Injury & Wound Healing
- Pathology
-
-
Question 39
Incorrect
-
An 80 year-old quadriplegic man has been lying supine for 7 weeks in a critical care ward. He develops a right lung abscess that is draining by gravity to a particular region of the lung. Which is the most likely site of pus collection?
Your Answer: Lower lobe
Correct Answer: Superior segment of the lower lobe
Explanation:The superior segmental bronchus of the lower lobe of the right lung branches posteriorly off the intermediate bronchus or the inferior lobe bronchus. It is therefore more likely to receive fluid or foreign bodies that enter the right main bronchus especially when the patient is supine.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 40
Incorrect
-
Which of these conditions is mithramycin used for?
Your Answer: Rickets
Correct Answer: Hypercalcaemia of malignancy
Explanation:Mithramycin or Plicamycin is a tricyclic pentaglycosidic antibiotic derived from Streptomyces strains. It inhibits RNA and protein synthesis by adhering to DNA. It is used as a fluorescent dye and as an antineoplastic agent. It is also used to reduce hypercalcaemia, especially caused by malignancy. Plicamycin is currently used in multiple areas of research, including cancer cell apoptosis and as a metastasis inhibitor.
-
This question is part of the following fields:
- Pathology
- Pharmacology
-
-
Question 41
Incorrect
-
A patient presents with loss of fine touch and sense of proprioception in the lower part of the body (below T6). He is likely to have a lesion involving:
Your Answer: Cerebellum
Correct Answer: Gracile nucleus
Explanation:The gracile nucleus is located in the medulla oblongata and is one of the dorsal column nuclei involved in the sensation of fine touch and proprioception. It contains second-order neurons of the dorsal column–medial lemniscus system, that receive inputs from sensory neurones of the dorsal root ganglia and send axons that synapse in the thalamus.
The gracile nucleus and fasciculus carry epicritic, kinaesthetic and conscious proprioceptive information from the lower part of the body (below the level of T6 in the spinal cord). Similar information from the upper part of body (above T6, except for face and ear) is carried by the cuneate nucleus and fasciculus. The information from face and ear is carried by the primary sensory trigeminal nucleus.
-
This question is part of the following fields:
- Neurology
- Physiology
-
-
Question 42
Incorrect
-
Biopsy of a neoplastic mass was performed. Histologic examination of the specimen showed spindle shaped cells with high nuclear/cytoplasm ratio on immunohisto chemical staining. These pleomorphic cells were vimentin positive, cytokeratin negative and cd45 negative. This type of neoplasm is most commonly found in which patient?
Your Answer: A 28 year old patient with obstructive jaundice and positive trousseau sign
Correct Answer: A 15-year-old boy with a mass in the left femur and lung metastases
Explanation:A histology report that describes spindle shaped cells which are vimentin positive suggests osteosarcoma and hematogenous spread to the lungs.
-
This question is part of the following fields:
- Neoplasia; Orthopaedics
- Pathology
-
-
Question 43
Correct
-
Renal function is an indication of the state of the kidney, measured by glomerular filtration rate (GFR). In a healthy person, GFR would be greatly increased by:Â
Your Answer: Substantial increases in renal blood flow
Explanation:An increase in the rate of renal blood flow (RBF) greatly increases the glomerular filtration rate (GFR). The more plasma available (from increased RBF), the more filtrate is formed. Glomerular filtration rate (GFR) is the volume of fluid filtered from the renal (kidney) glomerular capillaries into the Bowman’s capsule per unit time. Central to the physiologic maintenance of GFR is the differential basal tone of the afferent and efferent arterioles.
-
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 44
Incorrect
-
A tumour growing in the posterior mediastinum is found in a 40-year-old man who presented to the out patient clinic with chest pain. Such a tumour is likely to compress the following structure:
Your Answer: Inferior vena cava
Correct Answer: Oesophagus
Explanation:The boundaries of the posterior mediastinum are: the superiorly through the sternal angle and T4/5, inferiorly, the diaphragm, anteriorly, by the middle mediastinal structures and posteriorly by the spinal cord. Structures in the posterior mediastinum include the descending thoracic aorta, the azygos system, oesophagus, thoracic duct and lymph nodes. The great vessels and structures at the root of the lung are part of the middle mediastinum. The oesophagus is the only structure in the posterior mediastinum among the choices.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 45
Incorrect
-
What occurs during cellular atrophy?
Your Answer: The cell disappears
Correct Answer: Cell size decreases
Explanation:Atrophy is the decrease in the size of cells, tissues, or organs. There are several causes including inadequate nutrition, poor circulation, loss of hormonal support or nerve supply, disuse, lack of exercise, or disease. An increase in cell size is termed hypertrophy which is distinguished from hyperplasia, in which the cells remain approximately the same size but increase in number.
-
This question is part of the following fields:
- Cell Injury & Wound Healing; Urology
- Pathology
-
-
Question 46
Correct
-
One sensitive indicator of heavy alcohol dependence is:
Your Answer: Elevated serum gamma-glutamyl transpeptidase
Explanation:Elevated serum gamma-glutamyl transpeptidase (GGT) may be the only laboratory abnormality in patients who are dependent on alcohol. Heavy drinkers may also have an increased MCV.
-
This question is part of the following fields:
- Hepatobiliary
- Physiology
-
-
Question 47
Correct
-
A 69 Year old lady presented to the emergency department following a massive myocardial infarction. She was found to be in hypotensive shock with focal neurological signs. Unfortunately the patient demised. What would be the expected findings on the brain biopsy?
Your Answer: Liquefactive necrosis
Explanation:Liquefactive necrosis is often associated with bacterial or fungal infections. However, hypoxic death of cells within the central nervous system can also result in liquefactive necrosis. The focal area is soft with a liquefied centre containing necrotic debris and dead white cells. This may later be enclosed by a cystic wall
-
This question is part of the following fields:
- Cell Injury & Wound Healing; Neurology
- Pathology
-
-
Question 48
Incorrect
-
During work up for a 29 year-old lady who complained of chest pain, a computed tomography showed a large mass in the posterior mediastinum. Which among the following structures could be involved?
Your Answer: Inferior vena cava
Correct Answer: Lymph glands
Explanation:Boundaries of the posterior mediastinum include:
Superior: a plane through the sternal angle and T4/5
Inferior: the diaphragm
Anterior: the middle mediastinal structures
Posterior the spinal cord.
Structures in the posterior mediastinum include the descending thoracic aorta, the azygos system, oesophagus, thoracic duct and lymph nodes. The great vessels and structures at the root of the lung are part of the middle mediastinum. In this case, the lymph nodes is the correct answer.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 49
Incorrect
-
Which nerve lies immediately medial to the psoas major muscle?
Your Answer: Ilioinguinal
Correct Answer: Obturator
Explanation:The obturator nerve is formed from the ventral divisions of the 2nd, 3rd and 4th lumbar nerves. It courses through the fibres of the psoas major and emerges from the medial border near the pelvic brim.
The iliohypogastric nerve comes from the first lumbar nerve and emerges from the upper part of the lateral border of psoas major.
The ilioinguinal nerve arises with the iliohypogastric nerve from the first lumbar nerve and also emerges from the lateral border of the psoas major muscle.
The lateral femoral cutaneous nerve comes from the posterior division of the 2nd and 3rd lumbar nerves to emerge from the lateral border of the psoas major muscle near its middle.
The femoral nerve also arises from the dorsal divisions, but of the 2nd, 3rd and 4th lumbar nerves and courses through the muscle fibres to emerge at the lower part of the lateral border.
The coccygeal nerve doesn’t arise from the lumbar plexus but from the sacral plexus.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 50
Incorrect
-
Whilst snorkelling, a 30-year old gentleman has the respiratory rate of 10/min, tidal volume of 550 ml and an effective anatomical dead space of 250 ml. Which of the following will bring about a maximum increase in his alveolar ventilation?
Your Answer: A 4x increase in tidal volume
Correct Answer: A 2x increase in tidal volume and a shorter snorkel
Explanation:Alveolar ventilation = respiratory rate × (tidal volume − anatomical dead space volume). Increase in respiratory rate simply causes movement of air in the anatomical dead space, with no contribution to the alveolar ventilation. By use of a shorter snorkel, the effective anatomical dead space will decrease and will cause a maximum rise in alveolar ventilation along with doubling of tidal volume.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 51
Correct
-
A 46-year old lady presents with chief complaints of a large mass in the left breast. Histopathology of the mass revealed a stromal component with an epithelial component. What is the likely lesion?
Your Answer: Phyllodes tumour
Explanation:Phyllodes tumours are large, quickly growing tumours which arise from the periductal stroma of the breast. These are fibroepithelial tumours and account for less than 1% of breast cancers. These tumours can be benign, borderline or malignant based on the histology. The tumour usually affects adult women, mostly between the age of 40 to 50 years. It can be confused with fibroadenoma, which however affects much younger patients.
-
This question is part of the following fields:
- Pathology
- Women's Health
-
-
Question 52
Correct
-
Dicloxacillin is an antibiotic; the subclass that dicloxacillin belongs to is:
Your Answer: Penicillin
Explanation:Dicloxacillin is a narrow-spectrum beta-lactam antibiotic. It is used to treat infections caused by susceptible Gram-positive bacteria and most effective against beta-lactamase-producing organisms such as Staphylococcus aureus. To decrease the development of resistance, dicloxacillin is recommended to treat infections that are suspected or proven to be caused by beta-lactamase-producing bacteria.
-
This question is part of the following fields:
- Pathology
- Pharmacology
-
-
Question 53
Incorrect
-
What is the arterial sequence for an analgesic to reach the latissimus dorsi muscle assuming that your starting point is at the subclavian vein?
Your Answer: Subclavian – axillary – thyrocervical trunk – suprascapular
Correct Answer: Subclavian – axillary – subscapular – thoracodorsal
Explanation:Assuming our starting point is the subclavian artery, the analgesic continues in the same vessel into the axillary artery, as it passes into the axilla. The axillary artery at the lower border of the subscapularis gives rise to the subcapsular artery which is considered the largest branch of the axillary artery. This circumflex scapular branch distributes a serratus branch before entering the substance of the muscle as the thoracodorsal artery.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 54
Incorrect
-
Renin is secreted by pericytes in the vicinity of the afferent arterioles of the kidney from the juxtaglomerular cells. Plasma renin levels are decreased in patients with:
Your Answer: Renal artery stenosis
Correct Answer: Primary aldosteronism
Explanation:Primary aldosteronism, also known as primary hyperaldosteronism or Conn’s syndrome, is excess production of the hormone aldosterone by the adrenal glands resulting in low renin levels. Most patients with primary aldosteronism (Conn’s syndrome) have an adrenal adenoma. The increased plasma aldosterone concentration leads to increased renal Na+ reabsorption, which results in plasma volume expansion. The increase in plasma volume suppresses renin release from the juxtaglomerular apparatus and these patients usually have low plasma renin levels. Salt restriction and upright posture decrease renal perfusion pressure and therefore increases renin release from the juxtaglomerular apparatus. Secondary aldosteronism is due to elevated renin levels and may be caused by heart failure or renal artery stenosis.
-
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 55
Incorrect
-
A 42-year old woman presents to the doctor with jaundice. Her investigations show conjugated hyperbilirubinemia, raised urine bilirubin levels and low urine urobilinogen levels. What is the likely cause of her jaundice?
Your Answer: Gilbert syndrome
Correct Answer: Blockage of the common bile duct
Explanation:The description of the patient here fits the diagnosis of obstructive jaundice or cholestasis, which results in conjugated hyperbilirubinemia. Cholestasis occurs due to impairment of bile flow, which can be anywhere from the liver cell canaliculus to the ampulla of Vater. Causes can be divided into intrahepatic and extrahepatic.
– Intrahepatic causes include hepatitis, drug toxicity, alcoholic liver disease, primary biliary cirrhosis, cholestasis of pregnancy and metastatic cancer.
– Extrahepatic causes include common duct stone, pancreatic cancer, benign stricture of the common duct, ductal carcinoma, pancreatitis and sclerosing cholangitis.
There is absence of bile constituents in the intestine, which causes spillage in the systemic circulation. Symptoms include pale stools, dark urine, pruritus, malabsorption leading to steatorrhea and deficiency of fat-soluble vitamins. Chronic cases can result in osteoporosis or osteomalacia due to vitamin D deficiency and Ca2+ malabsorption. Cholesterol and phospholipid retention produces hyperlipidaemia despite fat malabsorption (although increased liver synthesis and decreased plasma esterification of cholesterol also contribute); triglyceride levels are largely unaffected. The lipids circulate as a unique, low-density lipoprotein called lipoprotein X.
-
This question is part of the following fields:
- Gastroenterology
- Physiology
-
-
Question 56
Incorrect
-
A 60 year-old patient being treated for hypertension presents to the ED with swelling of the left upper limb due to poor venous return. On examination, it is found that an aneurysm of the ascending aorta is impinging on a large vein lying immediately anterosuperior to it. Which vein is it likely to be?
Your Answer: Right brachiocephalic
Correct Answer: Left brachiocephalic
Explanation:Among the veins listed, only the left brachiocephalic vein is anterosuperior to the ascending aorta. The right brachiocephalic vein being on the right side would not be affected by the aortic aneurysm.
The azygos vein lies deep in the chest on the right side.
The internal thoracic vein lies interior to the anterior wall of the chest.
The left superior intercostal vein is close to the aortic arch, crossing it laterally. This vein drains the 2nd to 4th interspaces on the left side.
The Right internal jugular vein joins the right brachiocephalic vein which would not be affected by the aneurysm.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 57
Incorrect
-
A 59-year old gentleman admitted for elective cholecystectomy was found to have a haemoglobin 12.5 g/dl, haematocrit 37%, mean corpuscular volume 90 fl, platelet count 185 × 109/l, and white blood cell count 32 × 109/l; along with multiple, small mature lymphocytes on peripheral smear. The likely diagnosis is:
Your Answer: Cytomegalovirus infection
Correct Answer: Chronic lymphocytic leukaemia
Explanation:CLL or chronic lymphocytic leukaemia is the most common leukaemia seen in the Western world. Twice more common in men than women, the incidence of CLL increases with age. About 75% cases are seen in patients aged more than 60 years. The blood, marrow, spleen and lymph nodes all undergo infiltration, eventually leading to haematopoiesis (anaemia, neutropenia, thrombocytopenia), hepatomegaly, splenomegaly and decreased production of immunoglobulin. In 98% cases, CD+5 B cells undergo malignant transformation.
Often diagnosed on blood tests while being evaluated for lymphadenopathy, CLL causes symptoms like fatigue, anorexia, weight loss, pallor, dyspnoea on exertion, abdominal fullness or distension. Findings include multiple lymphadenopathy with minimal-to- moderate hepatomegaly and splenomegaly. Increased susceptibility to infections is seen. Herpes Zoster is common. Diffuse or maculopapular skin infiltration can also be seen in T-cell CLL.
Diagnosis is by examination of peripheral blood smear and marrow: hallmark being a sustained, absolute leucocytosis (>5 ×109/l) and increased lymphocytes in the marrow (>30%). Other findings can include hypogammaglobulinemia (<15% of cases) and, rarely, raised lactate dehydrogenase (LDH). Only 10% cases demonstrate moderate anaemia and/or thrombocytopenia.
-
This question is part of the following fields:
- Haematology
- Pathology
-
-
Question 58
Incorrect
-
The collaborative effort of the lateral pterygoid muscles produces which action on the jaw?
Your Answer: Have no effect on the mandible
Correct Answer: Protrude the mandible
Explanation:The combined effort of the lateral pterygoid muscles results in the protrusion of the mandible. The lateral pterygoid muscle is a muscle of mastication located superiorly to the medial pterygoid muscle and has two heads. The superior head originates on the infratemporal surface and infratemporal crest of the greater wing of the sphenoid bone, and the inferior head on the lateral surface of the lateral pterygoid plate. The insertion of this muscle is on the front margin of the articular disc of the temporomandibular joint. The unilateral contraction of the pterygoid muscle results in the laterotrusion of the mandible. It is important to note that the lateral pterygoid muscle is the only muscle of mastication that can open the jaw.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 59
Incorrect
-
Which of the following veins is prostate cancer most likely to metastasize through?
Your Answer: Testicular vein
Correct Answer: Internal vertebral venous plexus
Explanation:The internal vertebral veins are the most likely route of metastasis as they are valveless. They serve an important clinical role as they are the route of free travel for cancerous cells to other body structures. The other veins on the list have valves and would be the least likely routes for metastasis.
-
This question is part of the following fields:
- Anatomy
- Neurology
-
-
Question 60
Incorrect
-
Ventricular filling follows a delay caused by?
Your Answer: Bundle branches
Correct Answer: AV node
Explanation:The AV node is a conducting tissue found between the atria and the ventricles of the heart. It conducts electrical signal from the atria to the ventricles and acts a delaying mechanism preventing the atria and the ventricles from contracting at the same time. This decremental conduction prevents premature ventricular contraction in cases such as atrial fibrillation. A delay in the AV node is the reason for the PR segment seen on the ECG. In certain types of supraventricular tachycardia, a person could have two AV nodes; this will cause a loop in electrical current and uncontrollably rapid heart beat. When this electricity catches up with itself, it will dissipate and return to a normal heart rate.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 61
Incorrect
-
When you rest your elbows on a desk, what bony landmark of the upper limb are you resting on?
Your Answer: Coronoid process of the ulna
Correct Answer: Olecranon process of the ulna
Explanation:At the upper and back part of the ulna, there exists a curved eminence which is the olecranon process. This process lodges in the olecranon fossa of the humerus. It’s posterior surface is subcutaneous and this triangular area is what you rest your elbow upon.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 62
Incorrect
-
Electrophoresis is used to detect antibodies (immunoglobulins) in a blood sample from the umbilical artery of a new born. Which antibodies have the highest percentage in a new-born?
Your Answer: IgD
Correct Answer: IgG
Explanation:IgG is a monomeric immunoglobulin. It is formed by two heavy chains and two light chains and has two binding sites. Its is the most abundant antibody that is equally distributed in the blood and the tissues. It is the only antibody that can pass through the placenta and thus the only antibody present in the baby after it is born. There are four subclasses: IgG1 (66%), IgG2 (23%), IgG3 (7%) and IgG4 (4%). IgG1, IgG3 and IgG4 cross the placenta easily
-
This question is part of the following fields:
- General
- Physiology
-
-
Question 63
Incorrect
-
How much blood can the pulmonary vessels of a 45-year-old healthy man accommodate when he is at rest?
Your Answer: 150 ml
Correct Answer: 500 ml
Explanation:Pulmonary circulation is the portion of the cardiovascular system which carries deoxygenated blood away from the heart, to the lungs, and returns oxygenated blood back to the heart. The vessels of the pulmonary circulation are very compliant (easily distensible) and so typically accommodate about 500 ml of blood in an adult man. This large lung blood volume can serve as a reservoir for the left ventricle, particularly during periods when left ventricular output momentarily exceeds venous return.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 64
Incorrect
-
As per the Poiseuille-Hagen formula, doubling the diameter of a vessel will change the resistance of the vessel from 16 peripheral resistance units (PRU) to:
Your Answer: 2 PRU
Correct Answer: 1 PRU
Explanation:Poiseuille-Hagen formula for flow in along narrow tube states that F = (PA– PB) × (Π/8) × (1/η) × (r4/l) where F = flow, PA– PB = pressure difference between the two ends of the tube, η = viscosity, r = radius of tube and L = length of tube. Also, flow is given by pressure difference divided by resistance. Hence, R = 8ηL ÷ Πr4. Hence, the resistance of the vessel changes in inverse proportion to the fourth power of the diameter. So, if the diameter of the vessel is increased to twice the original, it will lead to decrease in resistance to one-sixteenth its initial value.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 65
Incorrect
-
During a procedure in the mediastinum, the surgeon accidentally injured a key structure that lies immediately anterior to the thoracic duct. Which structure is likely to be injured?
Your Answer: Trachea
Correct Answer: Oesophagus
Explanation:In the mid-thorax, the azygos vein, thoracic duct and aorta (in this order from right to the left) are all located posterior to the oesophagus. The superior vena cava, left internal jugular vein and trachea are not found in the mid thorax.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 66
Incorrect
-
If your EEG shows waves with a frequency range of 8-12 Hz, the waves most likely to be seen are:
Your Answer: Gamma
Correct Answer: Alpha
Explanation:Electroencephalography (EEG) is the neurophysiological measurement of the electrical activity of the brain. It is done by placing electrodes on the scalp or subdurally. In reality, the electrical currents are not measured, but rather the voltage differences between different parts of the brain. Four major types of EEG activity are recognized, which are alpha, beta, delta and theta.
Alpha waves, also known as Berger’s waves ranges in frequency from 8-12 Hz. Best detected with eyes closed, alpha waves are characteristic of a relaxed, alert state of consciousness. An alpha-like normal variant called mu is sometimes seen over the motor cortex (central scalp) and attenuates with movement or, rather, with the intention to move.
-
This question is part of the following fields:
- Neurology
- Physiology
-
-
Question 67
Incorrect
-
A 60-year old woman who has a left sided post-pneumonic effusion, was to have some pleural fluid aspirated for culture and sensitivity. If the medical intern in charge of the procedure decided to aspirate while the patient is sitting up on her bed, where in the pleural cavity would the fluid tend to accumulate?
Your Answer: Cupola
Correct Answer: Costodiaphragmatic recess
Explanation:The lowest part of the pleural cavity is the costodiaphragmatic recess and it the space in which the pleural fluid will accumulate when the patient sits up.
The cupola is part of the pleural cavity that extends into the root of the neck above the first rib.
The costomediastinal recess is the junction at which the costal pleura becomes the mediastinal pleura.
The middle mediastinum is the part of the mediastinum that is occupied by the heart.
The hilar reflection is the point where the mediastinal pleura is reflected to continue on as the visceral pleura.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 68
Incorrect
-
What is the normal amount of oxygen that is carried in the blood?
Your Answer: 5 ml oxygen/100 ml blood
Correct Answer: 20 ml oxygen/100 ml blood
Explanation:Normally, 100 ml of blood contains 15g haemoglobin and a single gram of haemoglobin can bind to 1.34 ml oxygen when 100% saturated. Thus, 15 × 1.34 = 20 ml O2/100 ml blood. The haemoglobin in venous blood that is leaving the tissues is about 75% saturated with oxygen, and hence it carries about 15 ml O2/100 ml venous blood. This implies that for each 10 ml of blood, 5 ml oxygen is transported to the tissues. With a p(O2) > 100 mm Hg, only 3 ml of oxygen is dissolved in every one litre of plasma. By increasing the pA(O2) by breathing 100% oxygen, one can add an extra amount of oxygen in the plasma, but the amount of oxygen carried by haemoglobin will not increase significantly as it is already > 95% saturated.
-
This question is part of the following fields:
- Physiology
- Respiratory
-
-
Question 69
Incorrect
-
Which is the correct order of tendons passing from medial to lateral-posterior to the medial malleolus?
Your Answer: Flexor digitorum longus, flexor hallucis longus, posterior tibial
Correct Answer: Posterior tibial, flexor digitorum longus, flexor hallucis longus
Explanation:The correct order of structures is the tendon of tibialis posterior, tendon of flexor digitorum longus, posterior tibial artery (and vein), tibial nerve and tendon of flexor hallucis longus.
-
This question is part of the following fields:
- Anatomy
- Lower Limb
-
-
Question 70
Incorrect
-
Question 71
Incorrect
-
The Henderson–Hasselbalch equation describes the derivation of pH as a measure of acidity. According to this equation, the buffering capacity of the system is at maximum when the number of free anions compared with undissociated acid is:
Your Answer: Two times more
Correct Answer: Equal
Explanation:In 1908, Lawrence Joseph Henderson wrote an equation describing the use of carbonic acid as a buffer solution. Later, Karl Albert Hasselbalch re-expressed that formula in logarithmic terms, resulting in the Henderson–Hasselbalch equation. The equation is also useful for estimating the pH of a buffer solution and finding the equilibrium pH in acid–base reactions. Two equivalent forms of the equation are: pH = pKa + log10 [A–]/[HA] or pH = pKa + log10 [base]/[acid]. Here, pKa is − log10(Ka) where Ka is the acid dissociation constant, that is: pKa = –log10(Ka) = –log10 ([H3 O+][A–]/[HA]) for the reaction: HA + H2 O ≈ A– + H3 O+ In these equations, A– denotes the ionic form of the relevant acid. Bracketed quantities such as [base] and [acid] denote the molar concentration of the quantity enclosed. Maximum buffering capacity is found when pH = pKa or when the number of free anions to undissociated acid is equal and buffer range is considered to be at a pH = pKa ± 1.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
-
-
Question 72
Incorrect
-
Which of the following is the most abundant WBC seen in a smear from a healthy person.
Your Answer: Basophils
Correct Answer: Neutrophils
Explanation:neutrophils are the most abundant cell type of the WBC. These phagocytes are found normally in the blood and increase in number are seen during an acute inflammation. These the percentages of WBC in blood Neutrophils: 40 to 60%
Lymphocytes: 20 to 40%
Monocytes: 2 to 8%
Eosinophils: 1 to 4%
Basophils: 0.5 to 1%
Band (young neutrophil): 0 to 3%. eosinophils, basophils, neutrophils are known as granulocytes and monocytes and lymphocytes as agranulocytes.
-
This question is part of the following fields:
- Inflammation & Immunology
- Pathology
-
-
Question 73
Incorrect
-
A 34-year-old woman is diagnosed with cerebral oedema after suffering a severe head trauma. Which of the following conditions is not likely to be associated with the extracellular oedema?
Your Answer: All answers are associated
Correct Answer: Increased plasma colloid osmotic pressure
Explanation:Cerebral oedema is extracellular fluid accumulation in the brain. Increased capillary permeability, increased capillary pressure, increased interstitial fluid colloid osmotic pressure and lymphatic blockage would increase fluid movement into the interstitial spaces. Increased plasma colloid osmotic pressure, however, would oppose fluid movement from the capillaries into the interstitial compartment.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
-
-
Question 74
Correct
-
A 35-year-old woman is in a comatose state following a traumatic head injury, and is receiving intravenous (IV) antibiotics and IV fluids containing saline and 5% dextrose. A serum biochemistry analysis is performed five days later which shows a low serum potassium level. This is most likely to be due to:
Your Answer: Nothing per oral regimen
Explanation:In this patient the cause for hypokalaemia is insufficient consumption of potassium as she is nil-per mouth with no intravenous supplementation. Parenteral nutrition has been used for comatose patients, although enteral feeding is usually preferable, and less prone to complications.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Physiology
-
-
Question 75
Incorrect
-
A 27-year-old woman has chronic low serum calcium levels. Which of the following conditions may be responsible for the hypocalcaemia in this patient?
Your Answer: Prolonged immobilisation
Correct Answer: Hypoparathyroidism
Explanation:Chronic hypocalcaemia is mostly seen in patients with hypoparathyroidism as a result of accidental removal or damage to parathyroid glands during thyroidectomy.
-
This question is part of the following fields:
- Fluids & Electrolytes
- Pathology
-
-
Question 76
Incorrect
-
During a street fight a boy sustained a laceration below the elbow. It was a deep cut that led to profuse bleeding from an artery situated on the supinator muscle immediately below the elbow. The vessel most likely to have been injured is?
Your Answer: Posterior ulnar recurrent artery
Correct Answer: Radial recurrent artery
Explanation:The radial recurrent artery is situated on the supinator muscle then passing between the brachialis and the brachioradialis muscles. It originates from the radial artery and ends by anastomosing with the terminal part of the Profunda brachii.
-
This question is part of the following fields:
- Anatomy
- Upper Limb
-
-
Question 77
Incorrect
-
A 6 year-old boy is brought to you coughing. He is suspected to have aspirated a Lego piece which he was seen playing with. Where would you expect the piece to be?
Your Answer: Terminal bronchiole of the right lung, lower lobe
Correct Answer: Right main bronchus
Explanation:Inhaled objects are more likely to enter the right lung for several reasons. First the right bronchus is shorter, wider and more vertical than the left bronchus. Also, the carina (a ridge-like structure at the point of tracheal bifurcation) is set a little towards the left. The terminal bronchiole is a very small space and impossible for the seed to lodge here.
-
This question is part of the following fields:
- Anatomy
- Thorax
-
-
Question 78
Incorrect
-
What is the most likely cause of prolonged bleeding time in a 40 year old women admitted for a laparoscopic cholecystectomy?
Your Answer: Haemophilia
Correct Answer: Thrombocytopaenia
Explanation:Bleeding time is related to platelet function, thus a decrease in platelet function, as seen in thrombocytopenia, DIC and von Willebrand disease in which platelet aggregation is defective, leads to an increase in bleeding time. It is not affected by a decrease or deficiency of any other clotting factors. Aspirin and other COX inhibitors prolong bleeding time along with warfarin and heparin.
-
This question is part of the following fields:
- General
- Physiology
-
-
Question 79
Incorrect
-
A 25 year old women is pregnant with her second child. She is A- blood group. Her first child was Rh+ and the father is also Rh+. The second child is at a risk of developing which condition?
Your Answer: Drug-induced haemolytic anaemia
Correct Answer: Haemolytic disease of the new-born
Explanation:This infant is at risk for haemolytic disease of the new born also known as erythroblastosis fetalis. In the pregnancy, Rh-positive RBC’s cross the placenta and enter the mothers blood system. She then becomes sensitised and forms IgG antibodies/anti-Rh antibodies against them. The second child is at a greater risk for this disease than the first child with Rh-positive blood group as during the second pregnancy, a more powerful response is produced. IgG has the ability to cross the placenta and bind to the fetal RBCs (type II hypersensitivity reaction) which are phagocytosed by the macrophages.
-
This question is part of the following fields:
- Inflammation & Immunology; Haematology
- Pathology
-
-
Question 80
Incorrect
-
Prostatectomy carries a risk of loss of penile erection due to injury to the prostatic plexus responsible for an erection. From which nerves do these fibres originate?
Your Answer: Pudendal
Correct Answer: Pelvic splanchnics
Explanation:Erection is a function of the parasympathetic nerves. Of the nerves listed, only the pelvic splanchnic nerves have parasympathetic fibres that innervate the smooth muscles and glands of the pelvic viscera.
-
This question is part of the following fields:
- Anatomy
- Pelvis
-
-
Question 81
Incorrect
-
A 72-year-old male presents with dysuria and chronic haematuria. He was diagnosed with bladder cancer and tumour invasion of the perivesical fat. What is the stage of the patient's bladder cancer?
Your Answer: Ta
Correct Answer: T3
Explanation:Bladder cancer is the growth of abnormal or cancerous cells on the inner lining of the bladder wall. The staging is as follows; stage 0is (Tis, N0, M0): Cancerous cells in the inner lining tissue of the bladder only, stage I (T1, N0, M0): tumour has spread onto the bladder wall, stage II (T2, N0, M0): tumour has penetrated the inner wall and is present in muscle of the bladder wall, stage III (T3, N0, M0): tumour has spread through the bladder to fat around the bladder and stage IV: (T4, N0, M0): tumour has grown through the bladder wall and into the pelvic or abdominal wall. The stage of cancer in the case presented is T3 because of the invasion of perivesical fat.
-
This question is part of the following fields:
- Neoplasia
- Pathology
-
-
Question 82
Incorrect
-
Signals pass through neuromuscular junctions via the neurotransmitter acetylcholine. After release from the skeletal neuromuscular junction, acetylcholine:
Your Answer: Enters the sarcoplasmic reticulum
Correct Answer: Causes postsynaptic depolarisation
Explanation:Acetylcholine is released from the presynaptic membrane into the cleft where it binds to the ion gated channels on the post synaptic membrane, causing them to open. This results in sodium entering into the fibre and further depolarizing it, creating an action potential.
-
This question is part of the following fields:
- General
- Physiology
-
-
Question 83
Incorrect
-
During cardiac catheterisation, if the blood sample from the catheter shows an oxygen saturation of 70%, and the pressure ranging from 12 to 24 mm Hg, it implies that the catheter tip is located in the:
Your Answer: Left atrium
Correct Answer: Pulmonary artery
Explanation:Normal values for various parameters are as follows:
Systolic arterial blood pressure (SBP): 90–140 mmHg.
Diastolic arterial blood pressure: 60–90 mmHg.
Mean arterial blood pressure (MAP): SBP + (2 × DBP)/3 (normal range: 70-105 mmHg).
Right atrial pressure (RAP): 2–6 mmHg.
Systolic right ventricular pressure (RVSP): 15–25 mmHg.
Diastolic right ventricular pressure (RVDP): 0–8 mmHg.
Pulmonary artery pressure (PAP): Systolic (PASP) is 15-25 mmHg and Diastolic (PADP) is 8–15 mmHg.
Pulmonary artery wedge pressure (PAWP): 6–12 mmHg.
Left atrial pressure (LAP): 6–12 mmHg.
Thus, the given value indicates that the position of catheter tip is likely to be in the pulmonary artery.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 84
Incorrect
-
Which of these antibiotics is the first choice treatment for infections caused by Pseudomonas aeruginosa?
Your Answer: Tetracycline
Correct Answer: Piperacillin
Explanation:Piperacillin is an extended-spectrum beta-lactam antibiotic of the ureidopenicillin class. It is normally used with a beta-lactamase inhibitor such as tazobactam. The combination has activity against many Gram-positive and Gram-negative pathogens and anaerobes, including Pseudomonas aeruginosa. Piperacillin is sometimes referred to as an anti-pseudomonal penicillin.
-
This question is part of the following fields:
- Pathology
- Pharmacology
-
-
Question 85
Incorrect
-
Which type of thyroid tumour represents 75 - 80% of thyroid cancer cases? This type is predominant in children and in patients who have had a previous history of head or neck radiation.
Your Answer: Follicular carcinoma
Correct Answer: Papillary carcinoma
Explanation:Papillary thyroid carcinoma is the most common thyroid cancer. This cancer has a high cure rate with 10-year survival rates for all patients with papillary thyroid cancer estimated at 80% to 90%.
-
This question is part of the following fields:
- Neoplasia
- Pathology
-
-
Question 86
Correct
-
The muscles of the superficial posterior compartment of the leg insert into the:
Your Answer: Calcaneus
Explanation:The muscles of the superficial posterior compartment of the leg form the characteristic ‘calf’ shape of the posterior leg and include the gastrocnemius, soleus and plantaris. The gastrocnemius and soleus together form a muscular mass which is occasionally described as the triceps surae; its tendon of insertion is the tendo calcaneus. The tendo calcaneus is the thickest and strongest in the body and together with the tendon of the plantaris muscle is inserted into the posterior part of the calcaneus.
-
This question is part of the following fields:
- Anatomy
- Lower Limb
-
-
Question 87
Incorrect
-
The cranial nerves of the brain provide motor and sensory innervation to the structures of the head and neck. Which of the following cranial nerves provide only motor innervation?
Your Answer: Optic
Correct Answer: Abducens
Explanation:The cranial nerves emerge directly from the brain and the brain stem. They provide sensory, motor or both motor and sensory innervation. Here is a summary of the cranial nerves and their function:
Olfactory – Purely sensory
Optic – Sensory
Oculomotor – Mainly motor
Trochlear – Motor
Trigeminal – Both sensory and motor
Abducens – Mainly motor
Facial – Both sensory and motor
vestibulocochlear – Mostly sensory
Glossopharyngeal – Both sensory and motor
Vagus – Both sensory and motor
Accessory – Mainly motor
Hypoglossal – Mainly motor
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 88
Incorrect
-
A 27-yeaar-old woman is diagnosed with candidiasis and prescribed fluconazole. What is the mechanism of action of fluconazole?
Your Answer: Inhibits viral protease
Correct Answer: Inhibits cytochrome P450
Explanation:Fluconazole is a triazole antifungal drug used in the treatment and prevention of superficial and systemic fungal infections. Like other imidazole- and triazole-class antifungals, fluconazole inhibits the fungal cytochrome P450 enzyme, 14-demethylase. It is used to treat candidiasis, blastomycosis, coccidioidomycosis, cryptococcosis, histoplasmosis, dermatophytosis, and pityriasis versicolor.
-
This question is part of the following fields:
- Pathology
- Pharmacology
-
-
Question 89
Incorrect
-
The thyrocervical trunk branches into which artery that passes upward and in front of the vertebral artery and longus colli muscle:
Your Answer: Internal thoracic
Correct Answer: Inferior thyroid
Explanation:The inferior thyroid artery is an artery in the neck. It arises from the thyrocervical trunk and passes upward, in front of the vertebral artery and longus colli muscle.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 90
Incorrect
-
A patient with testicular seminoma has the following tumour markers: LDH 1.3 times the reference levels, β-hCG 4500 mIU/ml and AFP 875 ng/ml. What's the serum tumour marker stage in this case?
Your Answer: S0
Correct Answer: S1
Explanation:According to AJCC guidelines, the serum tumour marker staging is the following:
S0: marker studies within normal limits
S1: lactate dehydrogenase (LDH) less than 1.5 times the reference range, beta-human chorionic gonadotrophin (β-hCG) <5000 mIU/ml, and alpha-fetoprotein (AFP) <1000 ng/ml S2: LDH 1.5–10 times the reference range, β-hCG 5000–50,000 mIU/ml or AFP 1000–10,000 ng/ml S3: LDH greater than 10 times the reference range, β-hCG >50,000 mIU/ml or AFP >10,000 ng/ml.
According to this, the patient’s tumour belongs to the S1 stage.
-
This question is part of the following fields:
- Pathology
- Urology
-
-
Question 91
Incorrect
-
Which of the cranial nerves is responsible for touch sensation on the skin over the maxilla region and the mandible?
Your Answer: Abducens
Correct Answer: Trigeminal
Explanation:The sensation of the face is provided by the trigeminal nerve which is cranial nerve V. It is also responsible for other motor functions such as biting and chewing. The trigeminal nerve has three branches; the ophthalmic nerve (V1), the maxillary nerve((V2) and the mandibular nerve (V3). These three branches exit the skull through separate foramina, namely; the superior orbital fissure, the foramen rotundum and the foramen ovale respectively. The mnemonic for this is ‘Standing room only’. The sensory fibres of the maxillary nerve are distributed to the lower eyelid and cheek, the nares and upper lip, the upper teeth and gums, the nasal mucosa, the palate and roof of the pharynx, the maxillary, ethmoid and sphenoid sinuses, and parts of the meninges. The sensory fibres of the mandibular nerve are distributed to the lower lip, the lower teeth and gums, the floor of the mouth, the anterior two-thirds of the tongue, the chin and jaw (except the angle of the jaw, which is supplied by C2–C3), parts of the external ear, and parts of the meninges. The mandibular nerve carries touch/ position and pain/temperature sensation from the mouth. The sensory fibres of the ophthalmic nerve are distributed to the scalp and forehead, the upper eyelid, the conjunctiva and cornea of the eye, the nose (including the tip of the nose), the nasal mucosa, the frontal sinuses and parts of the meninges (the dura and blood vessels). The sensory fibres of the maxillary nerve are distributed to the lower eyelid and cheek, the nares and upper lip, the upper teeth and gums, the nasal mucosa, the palate and roof of the pharynx, the maxillary, ethmoid and sphenoid sinuses, and parts of the meninges.
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 92
Incorrect
-
In what form are fats primarily transported in the body?
Your Answer: Phospholipids
Correct Answer: Free fatty acids
Explanation:Fat is mainly transported in the body as free fatty acids. Once out of the adipose cell, the free fatty acids get ionized and combine with albumin.
-
This question is part of the following fields:
- Gastroenterology
- Physiology
-
-
Question 93
Incorrect
-
A 50 year-old man, who sustained a head injury experienced sudden onset of horizontal double vision. He is diagnosed with lateral rectus palsy. Which of the following nerves is affected in this condition?
Your Answer: Trigeminal
Correct Answer: Abducent
Explanation:The lateral rectus muscle is one of the 6 extra-ocular muscles that control eye movements. It is responsible for abduction and is the only muscle that is innervated by the abducens nerve (CN VI).
-
This question is part of the following fields:
- Anatomy
- Head & Neck
-
-
Question 94
Incorrect
-
The gastrosplenic ligament also known as the gastrolienal ligament is the structure that connects the greater curvature of the stomach to the hilum of the spleen. Which of the following arteries would most likely be injured if a surgeon accidentally tore this ligament?
Your Answer: Middle colic
Correct Answer: Short gastric
Explanation:The short gastric arteries arise from the end of the splenic arteries and form five to seven branches. The short gastric arteries inside the gastrosplenic ligament from the left to the right, supply the greater curvature of the stomach. The hepatic artery proper runs inside the hepatoduodenal ligament. The right gastric artery and the left gastric artery are contained in the hepatogastric ligament. The caudal pancreatic artery branches off from the splenic artery and supplies the tail of the pancreas. The middle colic artery supplies the transverse colon. The splenic artery does not travel in the gastrosplenic ligament and so it would not be damaged by a tear to this ligament.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 95
Incorrect
-
The proximal tubule is the portion of the ductal system of the nephron of the kidney which leads from Bowman's capsule to the loop of Henle. Which of the following is most likely to be seen in a sample of fluid leaving the proximal tubule?
Your Answer: It will be hypertonic compared with plasma
Correct Answer: It will have no amino acids
Explanation:The proximal tubule is the portion of the duct system of the nephron leading from Bowman’s capsule to the loop of Henlé. The most distinctive characteristic of the proximal tubule is its brush border (or ‘striated border’). The luminal surface of the epithelial cells of this segment of the nephron is covered with densely packed microvilli forming a border which greatly increases the luminal surface area of the cells, presumably facilitating their reabsorptive function. Glucose, amino acids, inorganic phosphate, and some other solutes are100% reabsorbed via secondary active transport through co-transporters driven by the sodium gradient out of the nephron.
-
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 96
Incorrect
-
During an operation for a sigmoid colectomy the surgeon ligates the sigmoid arteries. From which artery do the sigmoid arteries branch?
Your Answer: Superior mesenteric artery
Correct Answer: Inferior mesenteric artery
Explanation:Sigmoid arteries are branches of the inferior mesenteric artery (IMA). Sigmoid artery gives off branches that supply the lower descending colon, the iliac colon and the sigmoid colon.
-
This question is part of the following fields:
- Abdomen
- Anatomy
-
-
Question 97
Correct
-
The most likely cause of prominent U waves on the electrocardiogram (ECG) of a patient is:
Your Answer: Hypokalaemia
Explanation:The U-wave, not always visible in ECGs, is thought to represent repolarisation of papillary muscles or Purkinje fibres. When seen, it is very small and occurs after the T-wave. Inverted U-waves indicate myocardial ischaemia or left ventricular volume overload. Prominent U-waves are most commonly seen in hypokalaemia. Other causes include hypercalcaemia, thyrotoxicosis, digitalis exposure, adrenaline and class 1A and 3 anti-arrhythmic agents. It can also be seen in congenital long-QT syndrome and in intracranial haemorrhage.
-
This question is part of the following fields:
- Cardiovascular
- Physiology
-
-
Question 98
Incorrect
-
Which of these substances is secreted by pericytes in the juxtaglomerular cells?
Your Answer: Prostaglandins
Correct Answer: Renin
Explanation:The juxtaglomerular cells synthesise, store and secrete the enzyme renin in the kidney. They are specialised smooth muscle cells in the wall of the afferent arteriole that delivers blood to the glomerulus and thus play a critical role in the renin– angiotensin system and so in renal autoregulation.
-
This question is part of the following fields:
- Physiology
- Renal
-
-
Question 99
Incorrect
-
The majority of gallstones are mainly composed of:
Your Answer: Calcium
Correct Answer: Cholesterol
Explanation:Bile salts are formed out of cholesterol in the liver cells. Occasionally, precipitation of cholesterol occurs resulting into cholesterol stones developing in the gall bladder.
These cholesterol gallstones are the most common type and account for 80% of all gallstones. Another type, accounting for 20% gallstones is pigment stones which are composed of bilirubin and calcium salts. Occasionally, stones of mixed origin are also seen.
-
This question is part of the following fields:
- Gastroenterology
- Physiology
-
-
Question 100
Incorrect
-
A 40-year old Caucasian male came to the hospital with complaints of fatigue and lethargy. On examination, he was found to have raised blood pressure. Urine examination showed >300 mg/dl proteinuria (4+) and 24-hour urine protein 3.5g. No glucose, blood, nitrites, urobilinogen or casts were present in urine. What is the most likely diagnosis?
Your Answer:
Correct Answer: Membranous glomerulonephritis
Explanation:Membranous glomerulonephritis or nephropathy, is a renal disorder with insidious course and usually affects people aged 30-50 years. 85% cases are primary (or idiopathic). The other 15% are secondary to autoimmune conditions like SLE, infections like malaria or hepatitis B, drugs like captopril and NSAIDs, or malignancies (particularly lung or colonic carcinoma). This disease is caused due to circulating immune complexes which are said to form by binding of antibodies to antigens in glomerular basement membrane. This antigens could be endogenous or derived from systemic circulation. This immune complex triggers the complement system, resulting in formation of membrane attack complex (MAC) on glomerular epithelial cells. This further results in release of proteases and oxidants which damage the capillaries making them ‘leaky’. Moreover, the epithelial cells also secrete a mediator to reduce nephron synthesis and distribution.
-
This question is part of the following fields:
- Pathology
- Renal
-
SESSION STATS - PERFORMANCE PER SPECIALTY
