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Question 1
Correct
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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: 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).
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 2
Correct
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During a radical mastectomy for advanced breast cancer, the surgeon injured the long thoracic nerve. Which among the following muscles is likely to be affected?
Your Answer: Serratus anterior
Explanation:The long thoracic nerve innervates the serratus anterior muscle which holds the scapula forward and balances the rhomboids and the trapezius muscles which retract the scapula. Injury to this nerve results in a ‘winged scapula’ with a posterior protrusion.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 3
Correct
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Question 4
Incorrect
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What best describes the muscles of the posterior compartment of the leg?
Your Answer: All are innervated by the femoral nerve
Correct Answer: One of the posterior compartment leg muscles laterally rotates the femur
Explanation:The muscles of the back of the leg are subdivided into two groups: superficial and deep. Superficial muscles include gastrocnemius, soleus and plantaris and are the chief extensors of the foot at the ankle joint. Deep muscles include the tibialis posterior, flexor hallucis longus, flexor digitorum longus and popliteus
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 5
Correct
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Where is factor VIII predominantly synthesised?
Your Answer: Vascular endothelium
Explanation:Factor VIII is an important part of the coagulation cascade. Deficiency causes haemophilia A. It is synthesised predominantly by the vascular endothelium and is not affected by liver disease. In the circulation it is bound to von Willebrand factor and it forms a stable complex with it. It is activated by thrombin or factor Xa and acts as a co factor to factor IXa to activate factor X which is a co factor to factor Va. Thrombin cleaves fibrinogen in fibrin and forms a meshwork to trap RBC and platelets to form a clot.
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This question is part of the following fields:
- General
- Physiology
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Question 6
Correct
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A 56-year-old woman complains of back pain, muscle spasms, weakness, and a burning sensation that radiates from her left hip to her toes. What's the most likely diagnosis?
Your Answer: Herniated nucleus pulposus
Explanation:A herniated disk will produce sensory disturbances, causing pain that radiates along the course of the sciatic nerve which is typically burning or stabbing, with or without back pain. The herniation is usually caused by age-related degeneration although trauma, injuries, or straining may also trigger it.
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This question is part of the following fields:
- Orthopaedics
- Pathology
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Question 7
Correct
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The transverse colon has two curvatures known as the colic flexures on each side of its lateral ends, the right and left. The left colic flexure found on the side of the descending colon is attached to an organ superiorly by a mesenteric ligament. Which organ is this?
Your Answer: Spleen
Explanation:The left colic flexure is the bend of the transverse colon as it continues to form the descending colon on the left upper quadrant. The spleen is located on the superior aspect of the left colic flexure. It is commonly referred to as the splenic flexure because of its relation o the spleen superiorly.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 8
Correct
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After being admitted to the hospital, a 60-year-old man is administered sodium nitroprusside. Which class of drugs does nitroprusside belong to?
Your Answer: Vasodilators
Explanation:Sodium nitroprusside is a potent peripheral vasodilator that affects both arterioles and venules. It is often administered intravenously to patients who are experiencing a hypertensive emergency. It reduces both total peripheral resistance as well as venous return, so decreasing both preload and afterload. For this reason it can be used in severe cardiogenic heart failure where this combination of effects can act to increase cardiac output. It is administered by intravenous infusion. Onset is typically immediate and effects last for up to ten minutes. The duration of treatment should not exceed 72 hours.
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This question is part of the following fields:
- Pathology
- Pharmacology
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Question 9
Incorrect
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A blood sample from a patient with polycythaemia vera will show which of the following abnormalities?
Your Answer: Decreased MCV
Correct Answer: High platelet count
Explanation:Polycythaemia is a condition that results in an increase in the total number of red blood cells (RBCs) in the blood. It can be due to a myeloproliferative syndrome, chronically low oxygen levels or rarely malignancy. In primary polycythaemia/ polycythaemia vera the increase is due to an abnormality in the bone marrow, resulting in increased RBCs, white blood cells (WBCs) and platelets. In secondary polycythaemia the increase occurs due to high levels of erythropoietin either artificially or naturally. The increase is about 6-8 million/cm3 of blood. A type of secondary polycythaemia is physiological polycythaemia where people living in high altitudes who are exposed to hypoxic conditions produce more erythropoietin as a compensatory mechanism for thin oxygen and low oxygen partial pressure.
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This question is part of the following fields:
- General
- Physiology
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Question 10
Incorrect
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Which of the following statements regarding aqueous humour is correct?
Your Answer: It only fills the anterior chamber of the eye
Correct Answer: Is the only source of nutrients for the lens of the eye
Explanation:The aqueous humour is a transparent, watery fluid similar to plasma, but containing low protein concentrations. It is secreted from the ciliary epithelium and fills both the anterior and the posterior chambers of the eye. It maintains the intraocular pressure and inflates the globe of the eye. It is this hydrostatic pressure which keeps the eyeball in a roughly spherical shape and keeps the walls of the eyeball taut. It provides nutrition (e.g. amino acids and glucose) for the avascular ocular tissues; posterior cornea, trabecular meshwork, lens, and anterior vitreous. It may serve to transport ascorbate into the anterior segment to act as an antioxidant agent. The presence of immunoglobulins indicate its role in immune response to defend against pathogens.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 11
Incorrect
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A patient who underwent emergency appendicectomy complains of having numbness (paraesthesia) of the skin at the pubic region. Which nerve was most likely injured in the operation?
Your Answer: Genitofemoral
Correct Answer: Iliohypogastric
Explanation:The iliohypogastric nerve comes from L1 and emerges from the upper part of the lateral border of the psoas major. It then crosses obliquely in front of the quadratus lumborum to the iliac crest where it perforates the posterior part of transversus abdominis and divides between that muscle and the internal oblique into a lateral and an anterior cutaneous branch. This provides sensory innervation to the skin of the lower abdominal wall, upper hip and upper thigh.
The genitofemoral nerve also comes from the lumbar plexus that innervates the skin of the anterior scrotum or labia majora and upper medial thigh.
The subcostal nerve is the ventral primary ramus of T12 providing sensory innervation to the anterolateral abdominal wall in an area superior to the pubic region.
A spinal nerve owing to their deep location would not have been injured in the procedure.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 12
Incorrect
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Which of these nerves controls adduction of hand?
Your Answer: Radial nerve
Correct Answer: Ulnar nerve
Explanation:The adductors of the fingers are the palmer interossei. They are supplied by the ulnar nerve, which is a branch of the medical cord of the brachial plexus.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 13
Correct
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Which of the deep fasciae located in the anterolateral abdominal wall form the inguinal ligament?
Your Answer: External abdominal oblique aponeurosis
Explanation:The inguinal ligament is the inferior border of the aponeurosis of the external oblique abdominis and extends from the anterior superior iliac spine to the pubic tubercle from whence it is reflected backward and laterally to attach to the pectineal line and form the lacunar ligament.
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This question is part of the following fields:
- Abdomen
- Anatomy
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Question 14
Correct
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Cranial nerve XII, the hypoglossal nerve, innervates which one of the following muscles in the list?
Your Answer: Hyoglossus
Explanation:The cranial nerve XII, hypoglossal nerve, innervates all the intrinsic and extrinsic muscles of the tongue except the palatoglossus. The muscles of the tongue innervated by this nerve include the extrinsic muscles; hyoglossus, styloglossus, genioglossus and the intrinsic muscles; superior longitudinal, inferior longitudinal, vertical and transverse muscles. The salpingopharyngeus, palatoglossus and the palatopharyngeus muscles are innervated by the vagus nerve. The stylopharyngeus muscle is innervated by the glossopharyngeal nerve (CN IX). The mylohyoid muscle is innervated by the inferior alveolar nerve, a branch of the mandibular nerve. Finally, the geniohyoid muscle is innervated by the olfactory nerve (CN I) via the hypoglossal nerve.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 15
Correct
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The collaborative effort of the lateral pterygoid muscles produces which action on the jaw?
Your 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.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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Question 16
Correct
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A 45-year-old woman was brought to the emergency department due to fever and chills. She has a history of recurrent UTI and complains of dysuria and urinary frequency. Urinary white blood cell count is >200 cell/high power field. If urine culture is performed, what is the most likely organism that will grow?
Your Answer: Escherichia coli
Explanation:The pathogen that most likely causes recurrent urinary tract infection in young women are E. coli, Enterococcus and Staphylococcus saprophyticus.
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This question is part of the following fields:
- Microbiology
- Pathology
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Question 17
Incorrect
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Leukotrienes normally function during an asthma attack and work to sustain inflammation. Which of the following enzymes would inhibit their synthesis?
Your Answer: Cyclooxygenase-2
Correct Answer: 5-lipoxygenase
Explanation:Leukotrienes are produced from arachidonic acid with the help of the enzyme 5-lipoxygenase. This takes place in the eosinophils, mast cells, neutrophils, monocytes and basophils. They are eicosanoid lipid mediators and take part in allergic and asthmatic attacks. They are both autocrine as well as paracrine signalling molecules to regulate the body’s response and include: LTA4, LTB4, LTC4, LTD4, LTE4 and LTF4.
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This question is part of the following fields:
- Inflammation & Immunology
- Pathology
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Question 18
Correct
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Hyperplastic arteriosclerosis with fibrinoid necrosis, petechial haemorrhages, microinfarcts in the kidneys and elevated plasma renin are common findings in which of the following patients?
Your Answer: A 45-year-old woman with scleroderma
Explanation:Scleroderma, also known as systemic sclerosis, is a chronic disease of the connective tissue. Involvement of the kidneys occurs in patients with diffuse scleroderma, causing rapid onset of high blood pressure with hyperreninemia, thrombotic microangiopathy, and progressive renal failure.
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This question is part of the following fields:
- Pathology
- Renal
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Question 19
Correct
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A medical intern wanting to perform her first thoracentesis (remove fluid from the pleural cavity) wishes to be reminded where to insert the needle to aspirate in order to avoid injuring the lung or neurovascular elements. Where is this place?
Your Answer: The bottom of interspace 9 in the midaxillary line
Explanation:Thoracentesis is performed in the costodiaphragmatic recess. The needle needs to be inserted below the level of the lungs to avoid injury to the lungs. At the paravertebral line, is between ribs 10 and 12, at the midaxillary line between ribs 8 and 10 and at the midclavicular line between interspaces 6 and 8. The needle should be inserted at the top of the rib (or the bottom of the interspace) to avoid damage to the neurovascular structures found below the rib running in the costal groove.
The recommended location for the needle insertion varies depending upon the source. It is critical that the patient hold his or her breath to avoid piercing of the lung.
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This question is part of the following fields:
- Anatomy
- Thorax
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Question 20
Correct
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A 50 year old woman presented with excessive bleeding after an inguinal hernia repair. Labs are suggestive of a primary haemostasis defect. Deficiency of which of the following is most likely to cause it?
Your Answer: Platelets
Explanation:Primary haemostatic control means the first line of defence against immediate bleeding. This is carried out by the platelets. They immediately form a haemostatic plug at the site of injury. Coagulation starts within 20s after an injury to the blood vessel which damage the endothelial cells. Secondary haemostasis follows which includes activation of the coagulation factors to form fibrin strands which mesh together forming the platelet plug. Platelets interact with platelet collagen receptor, glycoprotein Ia/IIa and to collagen fibres in the vascular endothelium. This adhesion is mediated by von Willebrand factor (vWF), which forms links between the platelet glycoprotein Ib/IX/V and collagen fibrils. The platelets are then activated and release the contents of their granules into the plasma, in turn activating other platelets and white blood cells.
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This question is part of the following fields:
- General
- Physiology
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Question 21
Correct
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Signals pass through neuromuscular junctions via the neurotransmitter acetylcholine. After release from the skeletal neuromuscular junction, acetylcholine:
Your 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.
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This question is part of the following fields:
- General
- Physiology
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Question 22
Correct
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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.
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This question is part of the following fields:
- Pathology
- Pharmacology
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Question 23
Correct
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After a car accident, a 30-year-old woman is alert and only has minor, superficial injuries. 2 hours later, she becomes unconscious and a CT scan reveals a convex, lens-shaped haemorrhage over the right parietal region. The most likely diagnosis is:
Your Answer: Epidural haematoma
Explanation:Epidural haematomas are usually caused by arterial bleeding, classically due to damage to the middle meningeal artery by a temporal bone fracture. Symptoms develop within minutes to several hours after the injury and consist of increasing headache, decreased level of consciousness, hemiparesis and pupillary dilation with loss of light reactivity. Around 15–20% of epidural hematomas are fatal.
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This question is part of the following fields:
- Neurology
- Pathology
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Question 24
Correct
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During hysterectomy, the ureter is most likely to be ligated when a surgeon is clamping the?
Your Answer: Uterine arteries
Explanation:The ureter forms the posterior boundary of a shallow depression which lodges the ovary and then runs medially and forward on the lateral aspect of the uterine cervix and upper part of the vagina to reach the fundus of the bladder. It is also situated about 2cm from the side of the cervix of the uterus. The relationship of the ureters and uterine arteries is of clinical significance because the arteries are at risk of iatrogenic injury during hysterectomy.
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This question is part of the following fields:
- Anatomy
- Pelvis
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Question 25
Correct
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A 17-year-old boy, who had developed shortness of breath and a loss of appetite over the last month, was referred to a haematologist because he presented with easy bruising and petechiae. His prothrombin time, platelet count, partial thromboplastin and bleeding time were all normal. Which of the following would explain the presence of the petechiae and easy bruising tendency?
Your Answer: Scurvy
Explanation:Scurvy is a condition caused by a dietary deficiency of vitamin C, also known as ascorbic acid. Humans are unable to synthesize vitamin C, therefore the quantity of it that the body needs has to come from the diet. The presence of an adequate quantity of vitamin C is required for normal collagen synthesis. In scurvy bleeding tendency is due to capillary fragility and not coagulation defects, therefore blood tests are normal.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 26
Correct
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A patient who complained of pain on the lower left side of the back had an x-ray done which confirmed a hernia passing posterolaterally, just superior to the iliac crest. Where is this hernia passing through?
Your Answer: Lumbar triangle
Explanation:The lumber triangle is bound medially by the border of the latissimus dorsi, laterally by the external abdominal oblique and by the iliac crest inferiorly. This is exactly where the hernia that is described is located.
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 27
Correct
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Selective destruction of which of the following cells will affect antibody synthesis?
Your Answer: Plasma cells
Explanation:Plasma cell are memory cells. After the antigen Is engulfed by the B cells it is presented to the CD4+ helper cells via the MCH II receptor and this leads to their activation which in turn stimulates the B cells to form antibodies against that specific antigen. Some B cells differentiate into plasma cells also called memory cells that get activated after subsequent infection.
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This question is part of the following fields:
- General
- Physiology
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Question 28
Incorrect
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A 57-year-old male smoker noted a lump on his inner lip. Upon physical examination the lump measured more than 2 cm but less than 4 cm in its greatest dimension. He is diagnosed with squamous cell carcinoma of the lip. What is the stage of the patient's cancer according to the TNM staging for head and neck cancers?
Your Answer: T1
Correct Answer: T2
Explanation:Head and neck cancer is a group of cancers that starts within the mouth, nose, throat, larynx, sinuses, or salivary glands. The TNM staging system used for head and neck cancers is a clinical staging system that allows physicians to compare results across patients, assess prognosis, and design appropriate treatment regimens. The staging is as follows; Primary tumour (T): Tis: pre-invasive cancer (carcinoma in situ), T0: no evidence of primary tumour, T1: tumour 2 cm or less in its greatest dimension, T2: tumour more than 2 cm but not more than 4 cm, T3: tumour larger than 4 cm, T4: tumour with extension to bone, muscle, skin, antrum, neck, etc and TX: minimum requirements to assess primary tumour cannot be met. Regional lymph node involvement (N): N0: no evidence of regional lymph node involvement, N1: evidence of involvement of movable homolateral regional lymph nodes, N2: evidence of involvement of movable contralateral or bilateral regional lymph nodes, N3: evidence of involvement of fixed regional lymph nodes and NX: Minimum requirements to assess the regional nodes cannot be met. Distant metastases (M): M0: no evidence of distant metastases, M1: evidence of distant metastases and MX: minimum requirements to assess the presence of distant metastases cannot be met. Staging: Stage I: T1 N0 M0, Stage II: T2 N0 M0, Stage III: T2NOMO and T3N1MO, Stage IV: T4N1M0, any TN2M0, any TN3M0, any T and any NM1. The depth of infiltration is predictive of the prognosis. With increasing depth of invasion of the primary tumour, the risk of nodal metastasis increases and survival decreases. The patient in this scenario therefore has a T2 tumour.
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This question is part of the following fields:
- Neoplasia
- Pathology
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Question 29
Correct
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If the blood flow is constant, oxygen extraction by tissues will show the greatest decrease due to which of the following interventions?
Your Answer: Tissue cooling
Explanation:With a constant blood flow to a given tissue bed, there will be an increase in oxygen extraction by the tissue with the following; an increase in tissue metabolism and oxygen requirements: warming (or fever), exercise, catecholamines and thyroxine. With cooling, the demand for oxygen decreases, leading to decreased oxygen extraction.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 30
Incorrect
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A patient is diagnosed with a tumour of the parotid gland. During surgical removal of the gland, which artery is vulnerable to injury?
Your Answer: Chorda tympani nerve
Correct Answer: External carotid artery
Explanation:The external carotid artery is a major artery of the head and neck. It arises from the common carotid artery when it splits into the external and internal carotid artery. It supplies blood to the face and neck. The external carotid artery begins opposite the upper border of the thyroid cartilage and, taking a slightly curved course, passes upward and forward and then inclines backward to the space behind the neck of the mandible, where it divides into the superficial temporal and internal maxillary arteries. It rapidly diminishes in size in its course up the neck, owing to the number and large size of the branches given off from it. At its origin, this artery is more superficial and placed nearer the midline than the internal carotid and is contained within the carotid triangle. The external carotid artery is covered by the skin, superficial fascia, platysma, deep fascia and anterior margin of the sternocleidomastoid. It is crossed by the hypoglossal nerve, by the lingual, ranine, common facial and superior thyroid veins; and by the digastric and stylohyoid; higher up it passes deeply into the substance of the parotid gland, where it lies deep to the facial nerve and the junction of the temporal and internal maxillary veins. It is here that it is in danger during surgery of the parotid gland.
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This question is part of the following fields:
- Anatomy
- Head & Neck
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SESSION STATS - PERFORMANCE PER SPECIALTY
