HUMAN ANATOMY AND PHYSIOLOGY

There are 40 multiple choice questions. Answer all of the questions and fill in the answer sheet making it clear which answer (s) you have chosen.PLEASE DO NOT submit all the questions, only submit the answer sheetQuestionnumber A B C D E F G Mark123456789101112131415161718192021222324252627282930313233343536373839401. A single stimulus applied to a skeletal muscle while it is relaxing from a twitch?a) will produce an action potential that will have no effect on the muscle force.b) will produce a second twitch whose force adds to the first.c) will cause a more rapid relaxation.d) will slow the relaxation although no additional force will be produced.e) will result in tetanus.2. The smallest unit of a normally innervated skeletal muscle that can be activated by a single nerve stimulus isa) a single sarcomere.b) a small group of sarcomeres close to the neuromuscular junction.c) a single myofilament.d) a single cell along its entire length.e) all the cells comprising a single motor unit.3. Which statement best describes the movement of calcium ions during the early stages of a skeletal muscle contraction?a) Calcium enter the cell primarily through the sarcolemma and activates the myofilaments.b) Calcium ions are released from the T tubules and diffuse to the myofilaments.c) Calcium ions are released from the terminal cisternae of the sarcoplasmic reticulum and diffuse to the region of the myofilaments.d) Calcium ions in the region of the myofilaments are rapidly pumped into the terminal cisternae of the sarcoplasmic reticulum.e) Calcium ions are released from the myofilaments and diffuse to the sarcoplasmic reticulum.4. Which of the following causes an increase in renal glucose threshold?a) A decrease in glomerular filtration rate.b) A decrease in the number of proximal tubule glucose carriers.c) Administration of a drug that inhibits glucose reabsorption.d) An increase in splay in the glucose reabsorption curve.e) None of the above.5. Which of the following provides the most accurate measure of glomerular filtration rate?a) Blood urea nitrogen.b) Endogenous creatinine clearance.c) Inulin clearance.d. PAH clearance.e) Plasma creatinine concentration.6. IP3 is thought to produce its biologic effects bya) directly activating calmodulin.b) directly stimulating protein kinase C.c) promoting release of calcium from intracellular stores into the cytoplasm.d) activating the alpha subunit of G proteins.e) both b and c.7. Which of the following decreases the rate of ACTH secretion?a) An increase in ADH in hypophyseal portal blood.b) Stress.c) Destruction of the parvicellular neurons in the paraventricular nuclei of the hypothalalmus.d) A decrease in glucocorticoids in the blood.e) Both a and d.8. Thyroid hormonesa) increase the sensitivity of the thyrotroph to TRH.b) stimulate the expression of the genes for the alpha and beta subunits of TSH in the thyrotroph.c) increase the secretion of TSH by thyrotroph.d) stimulate the expression of the gene for GH in the somatotroph.e) down regulate the expression of the gene for POMC.9. Chronic iodine deficiency in the diet would increase all of the following EXCEPTa) thyroid follicle cell numberb) concentration of TSH in the blood.c) thyroid follicle cell height.d) concentration of T4 in the blood.e) both c and d.10. Which statement best describes current knowledge of the postganglionic nerve fibres that control skin blood flow and sweating?a) Skin blood flow is controlled by adrenergic sympathetic nerves and sweating is controlled by cholinergic parasympathetic nerves.b) Skin blood flow is controlled by adrenergic sympathetic nerves and sweating is controlled by cholinergic sympathetic nerves.c) Skin blood flow is controlled by adrenergic sympathetic vasoconstrictor nerves and cholinergic sympathetic vasodilator nerves, sweating is controlled by cholinergic sympathetic nerves.d) Skin blood flow is controlled by adrenergic sympathetic vasoconstrictor nerves and sympathetic vasodilator nerves that secrete a neurotransmitter and sweating is controlled by cholinergic sympathetic nerves.e) Skin blood flow is controlled by adrenergic sympathetic vasoconstrictor nerves and cholinergic sympathetic vasodilator nerves and sweating is controlled by cholinergic parasympathetic nerves.11. Diabetes mellitus can be caused bya) defective insulin receptors.b) pancreatoectomy.c) increased resistance to the effects of insulin.d) Cushing’s syndrome.e) all of the above.12. What classification of epithelium would be present if its main function is protection against mechanical damage?a) Stratified columnar.b) Pseudostratified columnar.c) Stratified cuboid.d) Simple squamous.e) Stratified squamous.13. Which of the following is NOT correct? Release of ADH isa) inhibited by alcohol.b) triggered by ecstasy.c) triggered by exercise.d) inhibited by sleep.e) triggered by an increase in blood osmolarity.14. Select the statement that is NOT correct. After a meala) about 1/3 of the absorbed glucose is metabolized by the gut epithelial cells.b) about 1/3 of the absorbed glucose is metabolized by the skeletal muscle and fat cells.c) about 1/3 of the absorbed glucose is metabolized by brain and red blood cells.d) about 1/3 of the absorbed glucose is metabolized by the liver cells.e) glucose is used for energy and is also stored as glycogen.15. There is an increase in which of these glucose transporters on the cell surface of skeletal muscle cells, following an injection of insulin?a) GLUT 2b) GLUT 1c) GLUT 4d) SGLT 1e) GLUT 516. Even though each muscle fibre responds in all-or-none fashion, a whole muscle can contract with varying force because ofa) the lag phase of contraction.b) variable multiple motor unit summation.c) rigor mortis.d) different threshold values of each fibre.e) total tetanus of the muscle.17. A previously healthy 45 year old man is admitted to hospital with pneumonia. His blood pressure is 140/75 mmHg and his plasma concentration of sodium ions is 142 mEq/L; both are within the normal range. His condition is treated with intravenous antibiotics and fluids. On the third hospital day, his blood pressure in unchanged but his plasma sodium concentration is 130 mEq/L. His urine osmolarity is 450 mOsm/kg H20. He has no edema and his blood pressure does not change from a reclining to a standing position. What would be the most appropriate way to return the plasma sodium ion concentration to its normal value?a) Increase NaCl intake.b) Restrict NaCl intake.c) Increase water intake.d) Restrict water intake.e) Administer ADH.18. A 40 year of woman completes the London marathon in record time. Which of the following molecules is decreased in concentration or activity in her liver?a) Fructose 6-phosphate.b) Phosphoenolpyruvate carboxykinase.c) Fructose 2,6-bisphosphatase.d) Glucose-6-phosphatase.e) Phosphorylase.19. What of the following does NOT account for the ability to sustain contraction over a long period of time?a) Tetanus.b) Summation.c) Decreased creatine phosphate levels.d) Repeated firing of neurons.e) Repeated reuptake of calcium.20. The most important determinant of the sensation of thirst is thea) bloodpH.b) body temperature.c) circulating blood volume.d) intake of sodium in the diet.e) osmolarity of the plasma.21. A 50 year old man is frequently short of breath when performing tasks of moderate intensity. He is seen by his doctor who diagnoses exertional angina. The exertional angina is due to which of the following?a) Impaired calcium handling by the cardiac muscle.b) Altered sensitivity of the actin-myosin interactions.c) Depletion of ATP in the cardiac muscle.d) Myocardial energy demands exceeding energy supply.e) Inhibition of sarcolemma calcium channels.22.What are the criteria for classifying epithelia?a) Cell shape, number of layers of cells and basal specialisations.b) Cell shape, number of layers of cells and apical specialisations.c) Function of the epithelium, number of layers of cells and apical specialisations.d) Cell shape, function of the epithelium and apical specialisations.e) Function of the epithelium, number of layers of cells and basal specialisations.23. During a routine medical check-up, a 25 year of man is found to have an enlarged heart. He is a professional athlete and does not have high blood pressure or high cholesterol levels and is otherwise in good health. He mentions that his father and paternal grandfather had both died at an early age of apparent heart attacks. A few months after the check-up, he died of an apparent heart attack. DNA analyses indicate mutations in a gene for cardiac myosin, at a site associated with familial cardiac hypertrophy. Analysis of the heart showed that many cardiac sarcomeres were in disarray, which was probably due to which of the following?a) Effects of physical training.b) Decreased ATP production by cardiac mitochondria.c) Development of arrhythmia.d) Myocardial infarction.e) Development of cardiac hypertrophy.24. The major site for carbohydrate digestion is thea) duodenum.b) colon.c) stomach.d) ileum.e) jejunum.25. A patient received a muscle relaxant before surgery but soon developed massive spontaneous contraction and increased heart rate. The patient began to hyperventilate and experienced a dramatic increase in body temperature. The doctor administered dantrolene, a blocker of SR calcium channels, which reversed the condition. The patient was later shown to have malignant hyperthermia. The massive contractions were likely to have been caused by which of the following?a) Hyperexcitability of the alpha motor neurons.b) Inhibition of acetylcholine esterase.c) Hyperexcitability of calcium channels in the sarcolemma.d) Hyperexcitability of calcium channels in the SR.e) Increased calcium sensitivity of the thin filaments.26. While playing a game of football, a 14 year old girl experiences difficulty in breathing. She exhibits intense anxiety, cyanosis, sweating and wheezing and had a heart rate of 120 beats per minute. A paramedic at the game administers oxygen and then transports her to hospital. The emergency department doctor administers a beta2-adrenergic agonist via an inhaler to relax her bronchiolar smooth muscle. Her breathing improves, but she reports severe fatigue. The beta2-adrenergic agonist was probably able to reverse the difficulty breathing by which of the following?a) cAMP-dependent phosphorylation of cardiac phospholamban.b) cGMP-dependent stimulation of airway smooth muscle myosin phosphatase.c) cAMP-dependent inhibition of airway smooth muscle myosin light-chain kinase.d) cGMP-dependent stimulation of cardiac sarcolemmal calcium pump.e) Phosphorylation of troponin 1 in cardiac and airway smooth muscle.27. Protective functions of the integumentary system include all of these EXCEPT:a) hairs in the nose and ears prevent entry of foreign materials.b) nails protect the ends of digits.c) skin glands produce alkaline secretions that kill bacteria.d) hair protects the head from abrasion and ultraviolet light.e) callus formation prevents damage by friction.28. The urine of a 13 year of boy turned dark brown several weeks after a bout of “strep throat”. The diagnosis is glomerulonephritis. The urine is dark brown because red blood cells are in the urine. Which of the flowing will also be in high concentration in this boy’s urine?a) Sodium ions.b) Potassium ions.c) Serum albumin.d) Creatinine.e) Urea.29. Recruitmenta) involves the formation of stronger cross bridges between actin and myosin.b) means more muscles are used.c) is the increasing activation of more motor units to increase contractile tension.d) involves more action potentials fired within a shorter time.e) means that more muscle cells are activated by the same neuron.30. Given these sources of energy during exercise:1. anaerobic glycolysis2. ATP and creatine phosphate in the cell3. aerobic respirationThe correct sequence for the use of these energy sources by muscle cells when an individual starts exercising is:a) 1,2,3b) 3,2,1c) 3,1,2d) 2,1,3e) 2,3,131. With a sustained fixed grip, muscle contraction is:a) isometricb) isoscelesc) isokineticd) isosmotice) isotonic32. Select all that apply. Bile saltsa) aresynthesised from haem.b) are steroid structures synthesised from cholesterol.c) are necessary for the absorption of water soluble vitamins.d) include salts of taurocholic acid and glycocholic acid.e) emulsify fats in the digestive tract.f) are conjugated to glucuronic acid.g) are produced in the liver.33. From the dialysis practical, which of the following is true?a) Salts equilibrate across the membrane tubing the fastest because they are the smallest molecule.b) Starch does not move through the dialysis tubing because there is no diffusion gradient.c) Water will not move into the dialysis tubing.d) Glucose moves across the dialysis tubing but does so more slowly because it can only move by facilitated diffusion.e) Starch is converted to glucose, and moves out of the tubing.34. Select the statement about insulin that is NOT correct.a) It is not needed for glucose entry into red blood cells.b) It is not needed for glucose entry into brain cells.c) It is needed for glucose entry into adipose cells.d) It is not needed for glucose entry into liver cells.e) It is not needed for glucose entry into skeletal muscle cells.35. Select all that apply. Kidney dialysisa) works on the principles of diffusion and ultrafiltration.b) uses a dialysate with a low pH so protons move out of the blood.c) utilises the principle of countercurrent flow to maximize extraction of waste products.d) uses a dialysate with a higher concentration of bicarbonate than is found in the blood to act as a buffer.e) utilises the principle of concurrent flow to maximize extraction of waste products.f) uses a dialysate with a high concentration of potassium and a low concentration of sodium.g) allows the removal of urea and creatinine from the blood.36. The most important determinant of the release of ADH from the neurohypophysis is thea) intake of sodium in the diet.b) bloodpH.c) osmolarity of the plasma.d) circulating blood volume.e) body temperature.37. Select the statement about renal function in a healthy young adult is NOT correct.a) The urine can be more or less concentrated than the plasma.b) Most of the filtered water is reabsorbed secondary to solute reabsorption.c) 65% of water and solute reabsorption occurs in the proximal convoluted tubule.d) Most of the filtered water is excreted in the urine unless ADH is present.e) About 100 ml of plasma are filtered each minute.38. Salivaa) contains lipase, to initiate fat digestion.b) production stimulated by the parasympathetic nervous system results in watery saliva to facilitate digestion.c) production stimulated by the sympathetic nervous system results in thick saliva to facilitate respiration.d) contains lysozyme, a natural antibiotic.e) All of the above.39. Select the statement about gastric function that is NOT correct.a) Gastric emptying is faster when the stomach becomes more distended.b) Gastric emptying is not affected by hormonal or nervous influences.c) Gastric emptying is slower when fat is present in the stomach.d) Lipid soluble substances such as alcohol can be absorbed from the stomach.e) Gastric emptying is faster when liquids are ingested compared to solids.40. Substances that activate glucagon release includea) insulin.b) adrenaline.c) glucose.d) somatostatin.e) None of the above.