00
Correct
00
Incorrect
00 : 00 : 00
Session Time
00 : 00
Average Question Time ( Secs)
  • Question 1 - From which fascia of the pelvic wall muscle does the levator ani muscle...

    Correct

    • From which fascia of the pelvic wall muscle does the levator ani muscle arise?

      Your Answer: Obturator internus

      Explanation:

      The levator ani muscle arises from the posterior surface of the superior ramus of the pubis lateral to the symphysis, behind the inner surface of the spine of the ischium and between these points from the obturator internus fascia. It is attached to the inner surface of the side of the lesser pelvic cavity, supports the viscera in the cavity and surrounds the various structures that pass through it.

    • This question is part of the following fields:

      • Anatomy
      • Pelvis
      381.4
      Seconds
  • Question 2 - A medical student is told a substance is freely filtered but is not...

    Correct

    • A medical student is told a substance is freely filtered but is not metabolised, secreted, or stored in the kidney. It has a plasma concentration of 1000 mg/l and its urine excretion rate is 25 mg/min, and the inulin clearance is 100 ml/min. What is the rate of tubular reabsorption of the substance?

      Your Answer: 75 mg/min

      Explanation:

      Reabsorption or tubular reabsorption is the process by which the nephron removes water and solutes from the tubular fluid (pre-urine) and returns them to the circulating blood. To calculate the reabsorption rate of substance Z we use the following equation: excretion = (filtration + secretion) – reabsorption. As this substance is freely filtered, its filtration rate is equal to that of inulin. So 25 = (100 + 0) – reabsorption. Reabsorption = 100 – 25 therefore reabsorption = 75 mg/min.

    • This question is part of the following fields:

      • Physiology
      • Renal
      21
      Seconds
  • Question 3 - A 58-year-old woman diagnosed with deep vein thrombosis had been using warfarin for...

    Correct

    • A 58-year-old woman diagnosed with deep vein thrombosis had been using warfarin for 10 days. When she presented to the doctor she had haemorrhagic bullae and necrotic lesions in her lower limbs and buttocks. Deficiency of which of the following proteins may have caused the necrotic skin lesions?

      Your Answer: Protein C

      Explanation:

      Warfarin-induced skin necrosis is a rare complication of anticoagulant therapy that requires immediate drug cessation. The most common cutaneous findings include petechiae that progress to ecchymoses and haemorrhagic bullae. Warfarin inactivates vitamin K-dependent clotting factors II, VII, IX, and X and vitamin K-dependent proteins C and S. The concentration of protein C falls more rapidly than other vitamin K-dependent factors because they have a shorter half-lives. Skin necrosis is seen mainly in patients with prior protein C deficiency.

    • This question is part of the following fields:

      • Haematology
      • Pathology
      14.2
      Seconds
  • Question 4 - In which of the following situations will fat necrosis occur? ...

    Incorrect

    • In which of the following situations will fat necrosis occur?

      Your Answer: Brain injury

      Correct Answer: Trauma to the breast

      Explanation:

      Fat necrosis is necrosis of adipose tissue with subsequent deposition of calcium, giving it a white chalky appearance. It is seen characteristically in trauma to the breast and the pancreas with subsequent involvement of the peripancreatic fat. In the breast it may present as a palpable mass with is usually painless or as an incidental finding on mammogram. Fatty acids are released from the traumatic tissue which combine with calcium in a process known as saponification, this is an example of dystrophic calcification in which calcium binds to dead tissue. The central focus is surrounded by macrophages and neutrophils initially, followed by proliferation of fibroblasts, neovascularization and lymphocytic migration to the site of the insult.

    • This question is part of the following fields:

      • Cell Injury & Wound Healing
      • Pathology
      14
      Seconds
  • Question 5 - The muscle that stabilizes the stapes is innervated by which of the following...

    Incorrect

    • The muscle that stabilizes the stapes is innervated by which of the following nerves?

      Your Answer: Trigeminal nerve

      Correct Answer: Facial nerve

      Explanation:

      The stapedius is the smallest skeletal muscle in the human body. At just over one millimetre in length, its purpose is to stabilize the smallest bone in the body, the stapes and is innervated by a branch of the facial nerve.

    • This question is part of the following fields:

      • Anatomy
      • Head & Neck
      8.6
      Seconds
  • Question 6 - A 28 years old women presents with a history of chronic cough with...

    Correct

    • A 28 years old women presents with a history of chronic cough with fever for the past 2 months. A chest x ray revealed a diffuse bilateral reticulonodular pattern. A transbronchial biopsy was performed and histological examination showed focal areas of inflammation with epithelioid macrophages, Langhans cells and lymphocytes. Which of the immune reaction is responsible for this?

      Your Answer: Type IV hypersensitivity

      Explanation:

      A reactivated tuberculosis with granuloma formation is characteristic of type IV reaction. It is also called a delayed type of hypersensitivity reaction and takes around 2-8 days to deliver. It is a cell mediated response with the involvement of CD8 and CD4 cells and the release of IL-1 from macrophages that further activate these CD cells.

      Granulomatous reactions are mostly cell-mediated.

      Type I reactions are allergic and anaphylactic reactions and type II are complement-mediated immune reactions.

    • This question is part of the following fields:

      • Inflammation & Immunology; Respiratory
      • Pathology
      18.2
      Seconds
  • Question 7 - An X ray of a 60 year old male brought to the accident...

    Incorrect

    • An X ray of a 60 year old male brought to the accident and emergency following a fall down stairs shows a fractured olecranon process of the right ulna with the line of fracture passing through the superior surface, disrupting a muscle. Which among the following muscles was most likely injured?

      Your Answer: Pronator teres

      Correct Answer: Triceps brachii

      Explanation:

      The superior surface of the olecranon process forms an attachment for the insertion of the triceps brachii on the posterior aspect. It also has a minor transverse groove for the attachment of part of the posterior ligament of the elbow on the anterior aspect.

    • This question is part of the following fields:

      • Anatomy
      • Upper Limb
      14.6
      Seconds
  • Question 8 - The pterygoid plexus receives tributaries from which of the following veins? ...

    Correct

    • The pterygoid plexus receives tributaries from which of the following veins?

      Your Answer: Maxillary vein

      Explanation:

      The pterygoid plexus of veins is the main venous component associated with the infratemporal fossa. It receives tributaries corresponding to the branches of the internal maxillary artery. This plexus communicates freely with the anterior facial vein; it also communicates with the cavernous sinus, by branches through the foramen of Vesalius, foramen ovale and foramen lacerum. The (internal) maxillary vein is a short trunk which accompanies the first part of the (internal) maxillary artery. It is formed by a confluence of the veins of the pterygoid plexus and passes backward between the sphenomandibular ligament and the neck of the mandible and unites with the temporal vein to form the posterior facial vein. It carries blood away from the infratemporal fossa.

    • This question is part of the following fields:

      • Anatomy
      • Head & Neck
      41.7
      Seconds
  • Question 9 - A 27 year old women had developed a darker complexion following a vacation...

    Correct

    • A 27 year old women had developed a darker complexion following a vacation to India. She had no erythema or tenderness. Her skin colour returned to normal over a period of 1 month. Which of the these substances is related to the biochemical change mentioned above?

      Your Answer: Tyrosine

      Explanation:

      The tanning process can occur due to UV light exposure as a result of oxidation of tyrosine to dihydrophenylalanine with the help of the tyrosinase enzyme within the melanocytes. Hemosiderin can impart a brown colour due to breakdown of RBC but its usually due to a trauma and is known as haemochromatosis.

      Lipofuscin gives a golden brown colour to the cell granules not the skin.

      Homogentisic acid is part of a rare disease alkaptonuria, with characteristic black pigment deposition within the connective tissue.

      Copper can impart a brown golden colour, but is not related to UV light exposure.

    • This question is part of the following fields:

      • Cell Injury & Wound Healing
      • Pathology
      4.5
      Seconds
  • Question 10 - A 45-year-old pregnant woman develops high blood pressure at 20 weeks. She complains...

    Correct

    • A 45-year-old pregnant woman develops high blood pressure at 20 weeks. She complains of headaches and swollen feet, and a test reveals proteinuria (350 mg/day). Which of the following is the most likely diagnosis?

      Your Answer: Pre-eclampsia

      Explanation:

      Pre-eclampsia (PE) is a disorder of pregnancy characterized by the onset of high blood pressure (two separate readings taken at least 6 h apart of 140/90 or more) and often a significant amount of protein in the urine (>300 mg of protein in a 24-h urine sample). While blood pressure elevation is the most visible sign of the disease, it involves generalised damage to the maternal endothelium of the kidneys and liver, with the release of vasopressive factors only secondary to the original damage. Pre-eclampsia may develop at varying times within pregnancy and its progress differs among patients; most cases present pre-term. It has no known cure apart from ending the pregnancy (induction of labour or abortion). It may also present up to 6 weeks post partum. Risk factors for pre-eclampsia include obesity, prior hypertension, older age, and diabetes mellitus.

    • This question is part of the following fields:

      • Physiology
      • Renal
      8.1
      Seconds
  • Question 11 - The thyroid gland is a large ductless gland located in which part of...

    Incorrect

    • The thyroid gland is a large ductless gland located in which part of the neck?

      Your Answer: Digastric triangle

      Correct Answer: Visceral space

      Explanation:

      The thyroid gland is an endocrine gland in the neck, consisting of two lobes connected by an isthmus. It is situated at the front and sides of the neck in the visceral space.

    • This question is part of the following fields:

      • Anatomy
      • Head & Neck
      13.6
      Seconds
  • Question 12 - A 20-year old boy presented with low grade fever, night sweats and weakness...

    Correct

    • A 20-year old boy presented with low grade fever, night sweats and weakness over two months. On examination, he had multiple, non-tender, cervical, supraclavicular and axillary adenopathy. Microscopy of lymph node biopsy showed the presence of Reed-Sternberg cells. He is likely suffering from:

      Your Answer: Hodgkin’s lymphoma

      Explanation:

      Hodgkin’s lymphoma is a disease characterized by malignant proliferation of cells of the lymphoreticular system. It can be localized or disseminated, and can involve the nodes, spleen, liver and marrow. Symptoms of the disease include non-tender lymphadenopathy, fever, night sweats, weight loss, itching and hepatosplenomegaly. Histologically, the involved nodes show the presence of Reed-Sternberg cells, which are large, binucleated cells, in a heterogenous cellular infiltrate of histiocytes, lymphocytes, monocytes, plasma cells and eosinophils.

    • This question is part of the following fields:

      • Haematology
      • Pathology
      17.7
      Seconds
  • Question 13 - Which cells are most commonly seen in a granulomatous lesion that suggests an...

    Incorrect

    • Which cells are most commonly seen in a granulomatous lesion that suggests an underlying chronic inflammation?

      Your Answer: Mast cells

      Correct Answer: Lymphocytes

      Explanation:

      Lymphocytes and monocytes are commonly and characteristically recognised in a case of chronic inflammation.

      Eosinophils and neutrophils are seen with acute inflammation.

      Mast cells release histamine in early inflammation.

      Basophils are seen with allergies.

      Plasma cells are seen with viral infection.

      Platelets are not characteristic of any type of inflammation.

    • This question is part of the following fields:

      • Inflammation & Immunology
      • Pathology
      11.1
      Seconds
  • Question 14 - A 40-year old man sustained a deep laceration to the sole of his...

    Incorrect

    • A 40-year old man sustained a deep laceration to the sole of his left foot. It was found that the belly of extensor digitorum muscle was lacerated and the lateral tarsal artery was severed. The lateral tarsal artery is a branch of the:

      Your Answer: Popliteal artery

      Correct Answer: Dorsalis pedis artery

      Explanation:

      The lateral tarsal artery arises from the dorsalis pedis, as the vessel crosses the navicular bone

    • This question is part of the following fields:

      • Anatomy
      • Lower Limb
      20.5
      Seconds
  • Question 15 - A 32-year-old man presents to the doctor complaining of pain in his left...

    Correct

    • A 32-year-old man presents to the doctor complaining of pain in his left calf whilst walking. He says that the pain goes away after a short period of rest but starts again during exercise or walking. The man reveals he has been a smoker for the last 15 years. His blood pressure, blood sugar and cholesterol level are normal. Artery biopsy shows intraluminal thrombosis and vasculitis. What's is the most likely cause of these findings?

      Your Answer: Buerger's disease

      Explanation:

      Thromboangiitis obliterans, also known as Buerger’s disease, is a rare type of occlusive peripheral arterial disease, usually seen in smokers, most commonly in men aged 20 to 40. Symptoms most often include intermittent claudication, skin changes, painful ulcers on extremities, pain in the extremities during rest and gangrene. Diagnosis is based on clinical findings, arteriography, echocardiography, and computed tomography angiography. A difference in blood pressure between arms, or between the arms and legs is a common finding. Electrocardiographic findings include nonspecific abnormality or normal results.

    • This question is part of the following fields:

      • Cardiovascular
      • Pathology
      18.6
      Seconds
  • Question 16 - Enlargement of the spleen as seen in Gaucher's disease pushes the spleen downward...

    Correct

    • Enlargement of the spleen as seen in Gaucher's disease pushes the spleen downward and medially. What structure limits the straight-vertical-downward movement?

      Your Answer: Left colic flexure

      Explanation:

      The left colic flexure (also known as the splenic flexure), is the point where the colon takes a sharp turn downwards. It is the point where the transverse colon ends and the descending colon begins. It is located immediately inferior to the spleen so an enlarged spleen must move medially to avoid this colic flexure.

      The left suprarenal gland is retroperitoneal.

      The Ligament of Treitz suspends the fourth part of the duodenum from the posterior abdominal wall.

      The stomach, pancreas and liver lie medial to the spleen and thus would not prevent a vertical downward movement.

    • This question is part of the following fields:

      • Abdomen
      • Anatomy
      6.7
      Seconds
  • Question 17 - A 50 year old male point was diagnosed with tennis elbow that became...

    Correct

    • A 50 year old male point was diagnosed with tennis elbow that became worse after he started playing basket ball over the last three months. He was admitted to the orthopaedic ward to have elbow braces fitted. What type of synovial joint is the elbow joint?

      Your Answer: Hinge

      Explanation:

      The elbow joint is one of the many synovial joints in the body. This joint is an example of the hinge joint as the humerus is received into the semilunar notch of the ulna and the capitulum of the humerus articulates with the fovea on the head of the radius, together acting as a hinge in one plane.

    • This question is part of the following fields:

      • Anatomy
      • Upper Limb
      18.2
      Seconds
  • Question 18 - A 36-year-old woman suddenly suffers from a generalized seizure. She was previously healthy....

    Incorrect

    • A 36-year-old woman suddenly suffers from a generalized seizure. She was previously healthy. An emergency CT scan reveals a mass in the posterior fossa, with distortion of the lateral ventricles. After removing the tumour, the biopsy reveals it contains glial fibrillary acidic protein (GEAP). What's the most likely diagnosis?

      Your Answer: Neuroblastoma

      Correct Answer: Astrocytoma

      Explanation:

      Astrocytomas are primary intracranial tumours derived from astrocyte cells of the brain. They can arise in the cerebral hemispheres, in the posterior fossa, in the optic nerve and, rarely, in the spinal cord. These tumours express glial fibrillary acidic protein (GFAP). In almost half of cases, the first symptom of an astrocytoma is the onset of a focal or generalised seizure. Between 60% and 75% of patients will have recurrent seizures during the course of their illness. Secondary clinical sequelae may be caused by elevated intracranial pressure (ICP) cause by the direct mass effect, increased blood volume, or increased cerebrospinal fluid (CSF) volume. CT will usually show distortion of the third and lateral ventricles, with displacement of the anterior and middle cerebral arteries. Histological diagnosis with tissue biopsy will normally reveal an infiltrative character suggestive of the slow growing nature of the tumour.

    • This question is part of the following fields:

      • Neurology
      • Pathology
      22.4
      Seconds
  • Question 19 - Which of the following is true about myasthenia gravis? ...

    Correct

    • Which of the following is true about myasthenia gravis?

      Your Answer: Response of skeletal muscle to nerve stimulation is weakened

      Explanation:

      An autoimmune disorder, myasthenia gravis leads to progressive muscle weakness. It occurs due to formation of antibodies against the nicotinic acetylcholine (ACh) receptor of the motor endplate, which leads to impaired neuromuscular transmission. Thus, nerve stimulation will lead to a weakened muscle response, but direct electrical stimulation will bring about a normal response. Diagnostic test includes improvement of muscle weakness by small doses of acetylcholinesterase inhibitors (physostigmine or edrophonium). However, a large dose of physostigmine worsens the weakness due to desensitisation of the endplate to persistent Ach. One of the investigative tools includes radiolabelled snake venom α-bungarotoxin. It is an in vitro study performed on muscle biopsy specimens and used to quantify the number of ACh receptors at the motor endplate.

    • This question is part of the following fields:

      • Neurology
      • Physiology
      18.1
      Seconds
  • Question 20 - The specimen sent to the pathologist for examination was found to be benign....

    Incorrect

    • The specimen sent to the pathologist for examination was found to be benign. Which one of the following is most likely a benign tumour?

      Your Answer: Haematoma

      Correct Answer: Warthin’s tumour

      Explanation:

      Warthin’s tumour is also known as papillary cystadenoma lymphomatosum. It is a benign cystic tumour of the salivary glands containing abundant lymphocytes and germinal centres. It has a slightly higher incidence in males and most likely occur in older adults aged between 60 to 70 years. This tumour is also associated with smoking. Smokers have an eight-fold greater risk in developing the tumour compared to non-smokers.

    • This question is part of the following fields:

      • Neoplasia
      • Pathology
      18.1
      Seconds
  • Question 21 - Lung compliance is increased by: ...

    Correct

    • Lung compliance is increased by:

      Your Answer: Emphysema

      Explanation:

      Lung compliance is increased by emphysema, acute asthma and increasing age and decreased by alveolar oedema, pulmonary hypertension, atelectasis and pulmonary fibrosis.

    • This question is part of the following fields:

      • Physiology
      • Respiratory
      2.7
      Seconds
  • Question 22 - Which portion of the renal tubule absorbs amino acids and glucose? ...

    Incorrect

    • Which portion of the renal tubule absorbs amino acids and glucose?

      Your Answer: Distal convoluted tubule

      Correct Answer: Proximal convoluted tubule

      Explanation:

      In relation to the morphology of the kidney as a whole, the convoluted segments of the proximal tubules are confined entirely to the renal cortex. Glucose, amino acids, inorganic phosphate and some other solutes are reabsorbed via secondary active transport in the proximal renal tubule through co-transport channels driven by the sodium gradient.

    • This question is part of the following fields:

      • Physiology
      • Renal
      5.5
      Seconds
  • Question 23 - A 29-year-old pregnant woman develops severe hypoxaemia with petechial rash and confusion following...

    Correct

    • A 29-year-old pregnant woman develops severe hypoxaemia with petechial rash and confusion following a fracture to her left femur. Which is the most probable cause of these symptoms in this patient?

      Your Answer: Fat embolism

      Explanation:

      Fat embolism is a life-threatening form of embolism in which the embolus consists of fatty material or bone marrow particles that are introduced into the systemic venous system. It may be caused by long-bone fractures, orthopaedic procedures, sickle cell crisis, parenteral lipid infusion, burns and acute pancreatitis. Patients with fat embolism usually present with symptoms that include skin, brain, and lung dysfunction.

    • This question is part of the following fields:

      • Cardiovascular
      • Pathology
      6.3
      Seconds
  • Question 24 - A 30 year old female suffered from mismatched transfusion induced haemolysis. Which substance...

    Incorrect

    • A 30 year old female suffered from mismatched transfusion induced haemolysis. Which substance will be raised in the plasma of this patient?

      Your Answer: Hemosiderin

      Correct Answer: Bilirubin

      Explanation:

      Bilirubin is a yellow pigment that is formed due to the break down of RBCs. Haemolysis results in haemoglobin that is broken down into a haem portion and globin which is converted into amino acids and used again. Haem is converted into unconjugated bilirubin in the macrophages and shunted to the liver. In the liver it is conjugated with glucuronic acid making it water soluble and thus excreted in the urine. Its normal levels are from 0.2-1 mg/dl. Increased bilirubin causes jaundice and yellowish discoloration of the skin.

    • This question is part of the following fields:

      • General
      • Physiology
      15
      Seconds
  • Question 25 - A 90-year-old man is prescribed spironolactone after his family notices his legs are...

    Correct

    • A 90-year-old man is prescribed spironolactone after his family notices his legs are swollen. What class of drugs does spironolactone belong to?

      Your Answer: Potassium-sparing diuretics

      Explanation:

      Spironolactone is a renal competitive aldosterone antagonist in a class of drugs called ‘potassium-sparing diuretics’, that is primarily used to treat fluid build-up due to heart failure, liver scarring, or kidney disease. It is also used in the treatment of high blood pressure, low blood potassium, early-onset puberty, and acne and excessive hair growth in women. Spironolactone inhibits the effect of aldosterone by competing for intracellular aldosterone receptors in the distal tubule cells. This increases the secretion of water and sodium, while decreasing the excretion of potassium.

    • This question is part of the following fields:

      • Pathology
      • Pharmacology
      9.3
      Seconds
  • Question 26 - Nephrotic syndrome is a condition that causes proteinuria, hypoalbuminemia and oedema. Which of...

    Correct

    • Nephrotic syndrome is a condition that causes proteinuria, hypoalbuminemia and oedema. Which of the following is the cause of the oedema in these patients?

      Your Answer: Decreased oncotic pressure

      Explanation:

      The glomeruli of the kidneys are the parts that normally filter the blood. They consist of capillaries that are fenestrated and allow fluid, salts and other small solutes to flow through, but normally not proteins. In nephrotic syndrome, the glomeruli become damaged allowing small proteins, such as albumin to pass through the kidneys into urine. Oedema usually occurs due to salt and water retention by the diseased kidneys as well as due to the reduced colloid oncotic pressure (because of reduced albumin in the plasma). Lower serum oncotic pressure causes fluid to accumulate in the interstitial tissues.

    • This question is part of the following fields:

      • Physiology
      • Renal
      6.2
      Seconds
  • Question 27 - A 35 year old patient presenting with haematemesis, heart burn and bloody stool...

    Incorrect

    • A 35 year old patient presenting with haematemesis, heart burn and bloody stool was diagnosed with a duodenal ulcer that had eroded the gastroduodenal artery. The patient was then rushed into theatre for an emergency procedure to control the haemorrhage. If the surgeon decided to ligate the gastroduodenal artery at its origin, which of the following arteries would most likely experience retrograde blood flow from collateral sources as a result of the ligation?

      Your Answer: Short gastric

      Correct Answer: Right gastroepiploic

      Explanation:

      In the stomach and around the duodenum, there are many arterial anastomoses. Ligation of the gastroduodenal artery would result in the retrograde flow of blood from the left gastroepiploic artery to the right gastroepiploic artery. The blood flows into the right gastroepiploic artery, a branch of the gastroduodenal artery from the left gastroepiploic artery that branches from the splenic artery. This retrograde blood flow is aimed at providing alternate blood flow to the greater curvature of the stomach.

    • This question is part of the following fields:

      • Abdomen
      • Anatomy
      25
      Seconds
  • Question 28 - Regarding abduction of the digits of the hand, which of the following is...

    Incorrect

    • Regarding abduction of the digits of the hand, which of the following is correct?

      Your Answer: The palmar interosseous muscles are the sole adductors of the digits

      Correct Answer: All of the adductors of the digits take at least part of their attachments from metacarpal bones

      Explanation:

      Lying on the palmer surfaces of the metacarpal bones are four palmar interossei which are smaller than the dorsal interossei. Arising from the entire length of the metacarpal bone of one finger, is a palmar interosseous, which is inserted into the side of the base of the first phalanx and the aponeurotic expansion of the extensor digitorum communis tendon to the same finger. All the interossei are innervated by the eighth cervical nerve, through the deep palmar branch of the ulnar nerve. The palmar interossei adducts the fingers to an imaginary line drawn longitudinally through the centre of the middle finger.

    • This question is part of the following fields:

      • Anatomy
      • Upper Limb
      16.8
      Seconds
  • Question 29 - A 60-year-old woman complains of left sided headaches which have been recurring for...

    Incorrect

    • A 60-year-old woman complains of left sided headaches which have been recurring for several years. She recently suffered from a focal seizure for the first time a few days ago. A CT scan shows a mass in the left hemisphere of the brain. The most likely diagnosis is:

      Your Answer: Schwannoma

      Correct Answer: Meningioma

      Explanation:

      Meningiomas are a common benign intracranial tumour, and their incidence is higher in women between the ages of 40-60 years old. Many of these tumours are asymptomatic and are diagnosed incidentally, although some of them may have malignant presentations (less than 2% of cases). These benign tumours can develop wherever there is dura, over the convexities near the venous sinuses, along the base of the skull, in the posterior fossa and, within the ventricles.

    • This question is part of the following fields:

      • Neurology
      • Pathology
      13.5
      Seconds
  • Question 30 - Calculate the pulmonary vascular resistance in an adult male with the following parameters:...

    Incorrect

    • Calculate the pulmonary vascular resistance in an adult male with the following parameters:

      Heart rate 70 beats/min

      Arterial [O2] 0.24 ml O2/min

      Venous [O2] 0.16 ml O2/mi

      Whole body O2 consumption 500 ml/min

      Pulmonary diastolic pressure 15 mmHg

      Pulmonary systolic pressure 25 mmHg

      Wedge pressure 5 mmHg.

      Your Answer: 4.5 resistance units (mmHg/l per min)

      Correct Answer: 2.0 resistance units (mmHg/l per min)

      Explanation:

      Pulmonary vascular resistance (PVR) = (Mean pulmonary artery pressure – Pulmonary capillary wedge pressure) divided by Cardiac output. To get cardiac output, Fick’s principle needs to be applied which states that VO2 = (CO × CAO2) – (CO × CVO2) where VO2 = oxygen consumption, CO = cardiac output, CA = oxygen concentration of arterial blood and CVO2 = oxygen concentration of venous blood. Thus, CO = VO2/CAO2– CVO2, CO = 500/0.24–0.16, CO = 500/0.8, CO = 6.25 l/min. To calculate mean pulmonary artery pressure, we use the formula: Mean pulmonary artery pressure = Diastolic pressure + 1/3(Systolic pressure – Diastolic pressure). Thus, Mean pulmonary artery pressure = 15 + 1/3(25 – 15) = 15 + 3. 33 = 18.33. Substituting these values in the first formula, PVR = 18.3–5/6.25 = 13.5/5.25 = 2.0 resistance units (mmHg/l per min) approximately.

    • This question is part of the following fields:

      • Cardiovascular
      • Physiology
      8.6
      Seconds

SESSION STATS - PERFORMANCE PER SPECIALTY

Anatomy (4/10) 40%
Pelvis (1/1) 100%
Physiology (5/8) 63%
Renal (3/4) 75%
Haematology (2/2) 100%
Pathology (7/12) 58%
Cell Injury & Wound Healing (1/2) 50%
Head & Neck (1/3) 33%
Inflammation & Immunology; Respiratory (1/1) 100%
Upper Limb (1/3) 33%
Inflammation & Immunology (0/1) 0%
Lower Limb (0/1) 0%
Cardiovascular (2/3) 67%
Abdomen (1/2) 50%
Neurology (1/3) 33%
Neoplasia (0/1) 0%
Respiratory (1/1) 100%
General (0/1) 0%
Pharmacology (1/1) 100%
Passmed