McqMate
Chapters
| 1. |
Regarding cellular components: |
| A. | peroxisomes are larger than lysosomes |
| B. | pH of lysosomes is higher than the rest of the cytoplasm |
| C. | microfilaments are hollow |
| D. | myosin 1 molecules are characteristically found in muscle cells |
| E. | microfilaments are made up of actin |
| Answer» E. microfilaments are made up of actin | |
| 2. |
Na+ -K+ -ATPase is an example of a/an: |
| A. | symport |
| B. | uniport |
| C. | biport |
| D. | antiport |
| E. | airport |
| Answer» D. antiport | |
| 3. |
Which decreases Na+ -K+ -ATPase pump activity? |
| A. | thyroid hormones |
| B. | dopamine |
| C. | G-actin |
| D. | intracellular sodium |
| E. | insulin |
| Answer» B. dopamine | |
| 4. |
Given that a person weighs 60kg and their haematocrit is 40%, their total blood volume is: |
| A. | 6L |
| B. | 5L |
| C. | 4L |
| D. | 3L |
| E. | cannot be calculated with the given information |
| Answer» B. 5L | |
| 5. |
What percentage of body weight is plasma? |
| A. | 2% |
| B. | 5% |
| C. | 8% |
| D. | 15% |
| E. | 20% |
| Answer» B. 5% | |
| 6. |
ECF volume can be estimated using: |
| A. | inulin |
| B. | D2O |
| C. | Evan’s blue |
| D. | radioactive chromium |
| E. | iron isotopes |
| Answer» A. inulin | |
| 7. |
The number of molecules in a mole is: |
| A. | 1 X 1026 |
| B. | 6 X 1026 |
| C. | 4 X 1026 |
| D. | 1 X 1023 |
| E. | 6 X 1023 |
| Answer» E. 6 X 1023 | |
| 8. |
The molecular mass of a substance is expressed in: |
| A. | moles |
| B. | Daltons |
| C. | equivalents |
| D. | osmoles |
| E. | grams |
| Answer» B. Daltons | |
| 9. |
Regarding mitochondria: |
| A. | genome inheritance is strictly maternal |
| B. | the citric acid cycle occurs at the outer membrane |
| C. | the space between the two membranes is called the matrix |
| D. | the mutation rate for mitochondrial DNA is less than for nuclear DNA |
| E. | involutions of the outer membrane are called cristae |
| Answer» A. genome inheritance is strictly maternal | |
| 10. |
Which volume of distribution is evaluated with which substance? |
| A. | plasma – D2O |
| B. | RBC volume – 51Cr |
| C. | ECF – Evans Blue |
| D. | Interstitial fluid – Inulin |
| E. | ICF – mannitol |
| Answer» B. RBC volume – 51Cr | |
| 11. |
Which is correct? |
| A. | blood volume is 8% total body weight |
| B. | 2/3 total body weight is ECF |
| C. | 75% of ECF is blood plasma |
| D. | water content of lean tissue is 25% |
| E. | total body water increases with increasing age |
| Answer» A. blood volume is 8% total body weight | |
| 12. |
For mitochondria, which is TRUE? |
| A. | NADH-DH, 5DH, bc, cox synthesise ATP |
| B. | the matrix is between the inner and outer mitochondrial DNA |
| C. | mitochondrial DNA is not transmitted paternally |
| D. | 99% of mitochondrial proteins are encoded by mitochondrial DNA |
| E. | ATP synthetase is powered by an electron gradient |
| Answer» C. mitochondrial DNA is not transmitted paternally | |
| 13. |
Which is TRUE? |
| A. | the cytoskeleton is composed of hydroxyapatites |
| B. | the mitotic spindle is composed of actin microtubules |
| C. | myosin is the most abundant protein in cells |
| D. | colchicine stabilises microtubules preventing organelle movement |
| E. | actin-myosin interaction allows cells to move |
| Answer» E. actin-myosin interaction allows cells to move | |
| 14. |
For the genome, which is TRUE? |
| A. | the human genome encodes 3 X 109 genes |
| B. | adenine binds to cytosine and guanine to thymine |
| C. | uracil replaces thymine in RNA |
| D. | 3% of DNA are introns |
| E. | haploid DNA in germ cells is single stranded |
| Answer» C. uracil replaces thymine in RNA | |
| 15. |
For transmembrane movement, which is TRUE? |
| A. | exocytosis requires Ca2+ and energy |
| B. | Na+ -K+ -ATPase is an example of facilitated diffusion |
| C. | amiloride activates epithelial Na+ channels |
| D. | clathrin is essential for vesicle exocytosis |
| E. | water can only enter cells via water channels |
| Answer» A. exocytosis requires Ca2+ and energy | |
| 16. |
For the Erlanger and Gasser classification, which is TRUE? |
| A. | Sunday morning syndrome mainly affects C fibres |
| B. | local anaesthetics primarily affect A fibres |
| C. | preganglionic autonomic fibres are type B |
| D. | C fibres have the largest diameter |
| E. | B fibres are the least susceptible to hypoxia |
| Answer» C. preganglionic autonomic fibres are type B | |
| 17. |
For the glial cells, which is TRUE? |
| A. | one schwann cell can myelinate up to 40 neurons |
| B. | oligodenotocytes are the scavenger cells of the CNS |
| C. | microglia are the scavenger cells of the PNS |
| D. | there are up to three glial cells per neuron in the nervous system |
| E. | protoplasmic astrocytesase found in grey matter |
| Answer» E. protoplasmic astrocytesase found in grey matter | |
| 18. |
For cardiac muscle, which is FALSE? |
| A. | HERG really is the acronym for human ether-a-go-go related gene |
| B. | intercolated discs are calcified structures within cardiac muscle cells |
| C. | resting membrane potential is -90mV |
| D. | cardiac muscle requires continuous supply of O2 to function |
| E. | cardiac muscle action potential time decreases with increasing heart rate |
| Answer» B. intercolated discs are calcified structures within cardiac muscle cells | |
| 19. |
For neurotransmitters, which is TRUE? |
| A. | acetylcholine is synthesised by true cholinesterase |
| B. | atropine blocks muscarinic cholinergic receptors |
| C. | catecholamines are formed from VMA (vanillylmandelic acid) |
| D. | adrenaline has a higher affinity for α rather than β adrenergic receptors |
| E. | dopamine is formed by COMT from tryptophan |
| Answer» B. atropine blocks muscarinic cholinergic receptors | |
| 20. |
Regarding body water, which is FALSE? |
| A. | 1/3 total body weight is extra and 2/3 intra cellular |
| B. | 60% of body weight is water |
| C. | plasma is 8% and total blood 10%, of body weight |
| D. | of extracellular fluid, 25% is vascular, 75% extravascular |
| E. | interstitial fluid is 15% of body weight |
| Answer» C. plasma is 8% and total blood 10%, of body weight | |
| 21. |
Chemical composition, which is TRUE? |
| A. | pH is the negative natural logarithm of [H+] |
| B. | pH 5 to pH 6 involves tenfold increase in [H+] |
| C. | pH remains 7.4 +/- 0.05 in ECF, stabilised by buffer |
| D. | H2O and CO2 H2CO3 H+ and HCO3-, adding H+ shifts the equilibrium to the right, while adding ??? shifts it to the left |
| E. | the Donnan effect does not contribute significantly to the balance of electrolyte between intra and extra vascular compartment |
| Answer» C. pH remains 7.4 +/- 0.05 in ECF, stabilised by buffer | |
| 22. |
Nerve fibres, which is FALSE? |
| A. | 70% of energy requirement of nerves is used in maintaining polarity across the recytlemina by action of Na-K ATPase |
| B. | metabolic rate of nerves doubles in max action |
| C. | “C” type fibres are non-myelinated and include some of the sympathetic preganglionic fibres |
| D. | “A” and “B” fibres are all myelinated |
| E. | effects of local anaesthetic are maximal in “C” fibres |
| Answer» C. “C” type fibres are non-myelinated and include some of the sympathetic preganglionic fibres | |
| 23. |
Regarding skeletal muscle, which is FALSE? |
| A. | metabolic rate of muscle may increase 100 times in maximal activity |
| B. | muscle cells can be excited chemically, mechanically and electrically, to produce action potentials in the cell membrane |
| C. | actin is a myosin-binding protein which is a molecular motor, converting ATP energy to monomers |
| D. | mitochondria are packed in between myofibrils |
| E. | T tubules occur over the junction of I and A bands |
| Answer» C. actin is a myosin-binding protein which is a molecular motor, converting ATP energy to monomers | |
| 24. |
More on muscles; which is TRUE? |
| A. | skeletal muscle cells act as syncytram, though intercellular communications |
| B. | some skeletal muscles are not subject to voluntary control |
| C. | smooth muscle contains regularly discharging pacemaker |
| D. | a variant of smooth muscle is found in the eye, which resembles skeletal muscle |
| E. | cardiac muscle does not contain regular striation |
| Answer» D. a variant of smooth muscle is found in the eye, which resembles skeletal muscle | |
| 25. |
More on muscles; which is FALSE? |
| A. | T tubules are extensions of extracellular space |
| B. | “cystems’ of SR are in contact with T-tubules |
| C. | myosin molecules combine to form thick filaments while actin, tropomyosin, and the troponins the t….. |
| D. | an individual muscle cell is a myofibril, containing myofilaments |
| E. | the sarcolemnia transmits action potentials |
| Answer» D. an individual muscle cell is a myofibril, containing myofilaments | |
| 26. |
In muscle construction, which is TRUE? |
| A. | only contraction is energy requiring, not relaxing |
| B. | sequestering of Ca2+ causes separation of actin-myosin bands and muscle relaxation |
| C. | ATPase clefts are on the tips of the myosin beads |
| D. | ryanodine receptors are voltage gated Ca2+ chains |
| E. | Troponin T inhibits the interaction of actin and myosin |
| Answer» B. sequestering of Ca2+ causes separation of actin-myosin bands and muscle relaxation | |
| 27. |
Action potentials: |
| A. | travel along neurons at a set velocity |
| B. | are only seen in neurons |
| C. | are generated initially by action of K+ voltage gated channels |
| D. | result from variation in Na+ and K+ membrane permeability |
| E. | are unidirectional impulses |
| Answer» D. result from variation in Na+ and K+ membrane permeability | |
| 28. |
The Na+ K+ ATPase pump: |
| A. | utilises ATP to pump out 2 Na+ ions for every 3 K+ ions |
| B. | activity is altered by insulin, aldosterone and thyroid hormones |
| C. | is only found in muscle and nervous tissue |
| D. | is made of α, β, and δ subunits |
| E. | ATP binds to the α subunit causing a protein configuration change |
| Answer» B. activity is altered by insulin, aldosterone and thyroid hormones | |
| 29. |
Which is TRUE? |
| A. | active transport is the major method for transport of glucose into cells |
| B. | facilitated diffusion utilises ATP to transport ions against their chemical or electrical gradients |
| C. | an example of an active transporter is the K+ H+ ATPase found in the gastric mucosa |
| D. | the H+ K+ ATPase is an example of an electrogenic pump |
| E. | none of the above |
| Answer» C. an example of an active transporter is the K+ H+ ATPase found in the gastric mucosa | |
| 30. |
The golgi apparatus, which is TRUE? |
| A. | is found only in secretory cells |
| B. | vesicles containing newly synthesised proteins bind to trans side of the apparatus |
| C. | constitutive pathway of cell secretion is responsible for further processing and storage of proteins |
| D. | is responsible for glycorylation of proteins |
| E. | none of the above |
| Answer» E. none of the above | |
| 31. |
With respect to protein synthesis: |
| A. | each amino acid found in human protein has its own individual single transfer RNA |
| B. | pre mRNA processing occurs in the cytoplasm prior to binding to ribosomes on the endoplasmic retic??? |
| C. | each gene has regulatory, promoter, coding and non coding regions which are all transcribed into pre mRNA |
| D. | introns no recognised physiological function |
| E. | the promoter site of a gene is the site where RNA polymerase binds |
| Answer» E. the promoter site of a gene is the site where RNA polymerase binds | |
| 32. |
Which is TRUE? |
| A. | polymerase chain reaction may be used to repair damaged DNA |
| B. | restriction fragment length polymorphism detects differences in DNA sequences between different individuals |
| C. | protein encoding genes make up only 15% of the human genome |
| D. | the only difference between DNA and RNA is the substitution of uracil for thymine |
| E. | the haploid human genome is made up of 3 X 106 base pairs |
| Answer» B. restriction fragment length polymorphism detects differences in DNA sequences between different individuals | |
| 33. |
Action potentials in skeletal muscle: |
| A. | travel along muscle fibres at varying rates |
| B. | have larger retratory periods compared to nerves |
| C. | causes uptake of Ca++ into sacroplasmic reticulum |
| D. | results in sustained contraction of muscle fibres |
| E. | the haploid human genome is made up of 3 X 106 base pairs |
| Answer» B. have larger retratory periods compared to nerves | |
| 34. |
Regarding membrane potential: |
| A. | it is only found in nervous tissue |
| B. | Na+/K+ pump does not contribute to the membrane potential |
| C. | its magnitude does not change from tissue to tissue |
| D. | the membrane potential is negative inside in relation to the outside |
| E. | it is mainly caused by leaking Na+/K+ channels |
| Answer» D. the membrane potential is negative inside in relation to the outside | |
| 35. |
Gamma amino butyric acid: |
| A. | is an excitatory mediator in the brain |
| B. | it is formed by decarboxylation of glutamates |
| C. | there are three different classes of GABA receptors |
| D. | it is mostly excreted unchanged in the urine |
| E. | is the main mediator in glutamate metabolism |
| Answer» B. it is formed by decarboxylation of glutamates | |
| 36. |
Substance P: |
| A. | is a carbohydrate |
| B. | is a polypeptide found in intestine and nervous tissue |
| C. | is a beta II amino acid residue mainly found in the liver |
| D. | it is not involved in the neuroendocrine system |
| E. | it is a lipid |
| Answer» B. is a polypeptide found in intestine and nervous tissue | |
| 37. |
Opioid peptides: |
| A. | are not formed from precursors |
| B. | morphine is an example of opioid peptides |
| C. | they form the opioid receptors in the brain |
| D. | are mainly found in the brain and gastrointestinal |
| E. | they are excreted unchanged almost always |
| Answer» D. are mainly found in the brain and gastrointestinal | |
| 38. |
Regarding the autonomic nervous system: |
| A. | does not have a reflex arc like somatic nervous system |
| B. | dopamine is the main transmitter |
| C. | cholinergic division of the autonomic nervous system increases activity of the intestinal musculature and increases gastric secretion |
| D. | norepinepherine is metabolised by pseudocholinesterase |
| E. | it is not involved with visceral sensation |
| Answer» C. cholinergic division of the autonomic nervous system increases activity of the intestinal musculature and increases gastric secretion | |
| 39. |
With respect to blood volume: |
| A. | the greater proportion is present in the arterial system |
| B. | the pulmonary vessels contain 50% |
| C. | the systemic capillaries and arterioles contain 7% |
| D. | the heart contains 20% |
| E. | the aorta contains 20% |
| Answer» C. the systemic capillaries and arterioles contain 7% | |
| 40. |
Blood pressure: |
| A. | fluctuates in the aorta between 180 and 20mmHg |
| B. | is approaching 0mmHg at the right atrium |
| C. | is half in the pulmonary arteries of that in the aorta |
| D. | is greater in large veins than the vena cava |
| E. | drops significantly at capillary level |
| Answer» B. is approaching 0mmHg at the right atrium | |
| 41. |
With respect to blood flow: |
| A. | during laminar flow, blood moves at greater velocity adjacent to the vessel wall |
| B. | turbulent flow can occur in long straight vessels |
| C. | during turbulent flow, there is less resistance to flow |
| D. | the tendency for turbulent flow increases inversely with the velocity of blood flow |
| E. | turbulent flow does not normally occur in the aorta |
| Answer» B. turbulent flow can occur in long straight vessels | |
| 42. |
As a percentage of total blood volume, which of the following values are CORRECT? |
| A. | 40% is in the pulmonary circulation |
| B. | 13% is in the systemic arteries |
| C. | 20% is in the systemic arterioles and capillaries |
| D. | 30% is in the veins |
| E. | none of the above are correct |
| Answer» B. 13% is in the systemic arteries | |
| 43. |
Which is NOT correct about reflex mechanisms acting on the circulation? |
| A. | the baroreceptors in the carotid bodies are stimulated when blood pressure increases |
| B. | the Bainbridge reflex causes increase in heart rate |
| C. | the Cushing reflex is a special central nervous system ischaemic response resulting from increased intracranial pressure |
| D. | the maximum firing per change in pressure of the carotid baroreceptors occurs at a mean arterial pressure of 90mmHg |
| E. | the glossopharyngeal nerve is involved in baroreceptor reflex system |
| Answer» A. the baroreceptors in the carotid bodies are stimulated when blood pressure increases | |
| 44. |
When the cholinergic vagal fibres to nodal tissues are stimulated: |
| A. | the membrane becomes hyper-polarised |
| B. | the slope of the pre-potential is decreased |
| C. | acetylcholine decreases conductance to Ca++ via muscarinic receptors |
| D. | acetylcholine increases the permeability of nodal tissues to K+ via muscarinic receptors |
| E. | all of the above are true |
| Answer» E. all of the above are true | |
| 45. |
Heart rate is accelerated by: |
| A. | decreased activity of baroreceptors in the left ventricle |
| B. | increased activity of baroreceptors in the pulmonary circulation |
| C. | increased intracranial pressure |
| D. | expiration |
| E. | increased activity of baroreceptors in the arteries |
| Answer» A. decreased activity of baroreceptors in the left ventricle | |
| 46. |
Regarding the physical characteristics of the circulation: |
| A. | arterioles have a strong muscular wall but can close completely |
| B. | the arterial system contains the greatest volume of blood at any given time |
| C. | the aorta has a greater total cross sectional area than the venae cavae |
| D. | velocity is directly proportional to the cross sectional area of the blood vessel |
| E. | Reynold’s number represents a measure of laminar blood flow |
| Answer» A. arterioles have a strong muscular wall but can close completely | |
| 47. |
Regarding a coronary blood flow: |
| A. | systolic blood flow in subendocardial arteries is greater than in the epicardial |
| B. | less than 50% of oxygen is removed during passage when in the resting state |
| C. | the coronary circulation is well supplied by parasympathetic vasodilatory fibres |
| D. | sympathetic vasoconstrictory fibres predominate in epicardial vessels |
| E. | none of the above |
| Answer» D. sympathetic vasoconstrictory fibres predominate in epicardial vessels | |
| 48. |
Active transport of Na+/K+ accounts for what percentage of energy utilised in cells and neurons? |
| A. | 20% cells, 50% neurons |
| B. | 24% cells, 50% neurons |
| C. | 24% cells, 70% neurons |
| D. | 30% cells, 70% neurons |
| E. | 30% cells, 90% neurons |
| Answer» C. 24% cells, 70% neurons | |
| 49. |
Human DNA – what proportion codes for proteins? |
| A. | 3% |
| B. | 13% |
| C. | 23% |
| D. | 33% |
| E. | 53% |
| Answer» A. 3% | |
| 50. |
Comparing nerve fibre types – which is FALSE? |
| A. | C fibres are most susceptible to local anaesthetic |
| B. | A fibres are least susceptible to local anaesthetic |
| C. | B fibres are found preganglionic – autonomic |
| D. | Aδ fibres transmit motor to muscle spindles |
| E. | some C fibres transmit postganglionic sympathetic impulses |
| Answer» D. Aδ fibres transmit motor to muscle spindles | |
| 51. |
Nicotinic receptors, which is FALSE? |
| A. | are found on sympathetic ganglia |
| B. | are found at the neuromuscular junction |
| C. | are activated by ACh |
| D. | cause activation of a G protein and ↑cAMP |
| E. | cause influx of Na+ via open Na+ channels |
| Answer» D. cause activation of a G protein and ↑cAMP | |
| 52. |
Serotonin is noted in all but: |
| A. | sexual behaviour |
| B. | obesity |
| C. | platelet aggregation |
| D. | mood |
| E. | vomiting |
| Answer» A. sexual behaviour | |
| 53. |
With respect to the ascending pathways of sensation within the spinal cord: |
| A. | the ??? columns connect with the medial branches (crosses midline) |
| B. | the central spinothalamic tract carries pain/temp fibres |
| C. | the lateral spinothalamic tract has small fibres medially |
| D. | gracile fasiculatus contains fibres from thoracic and cervical nerves |
| E. | proprioception is transmitted in the lateral spinothalamic tract |
| Answer» A. the ??? columns connect with the medial branches (crosses midline) | |
| 54. |
With respect to the EEG and brain wave activity – which is FALSE? |
| A. | the α rhythm (adults) has a frequency of 18-30/second |
| B. | infants have a faster β rhythm than adults |
| C. | the frequency of the α rhythm can be decreased with hypoglycaemia, hypothermia and increased ??? |
| D. | young adult – 25% sleep is REM sleep |
| E. | REM sleep is characterised by no muscle tone, but increased extraocular movement |
| Answer» B. infants have a faster β rhythm than adults | |
| 55. |
Which of the following decreases basal metabolic rate? |
| A. | recent ingestion of food |
| B. | stress |
| C. | increased thyroid hormones |
| D. | sleep |
| E. | lactation |
| Answer» D. sleep | |
| 56. |
Which of the following is an example of a low energy phosphate compound: |
| A. | creatine phosphate |
| B. | UTP |
| C. | acetyl CoA |
| D. | glucose-6 phosphate |
| E. | ATP |
| Answer» D. glucose-6 phosphate | |
| 57. |
Creatinuria occurs in measurable amounts in all but: |
| A. | women during and after pregnancy and occasionally in non-pregnant women |
| B. | normal men |
| C. | starvation |
| D. | thyrotoxicosis |
| E. | poorly controlled diabetes mellitus |
| Answer» B. normal men | |
| 58. |
Plasma lipids and lipid transport: |
| A. | apoprotein B48 occurs in VLDL |
| B. | apoprotein B166 and apoprotein C occurs in chylomicrons |
| C. | lecithin cholesterol acyltrasferase is responsible for transferring cholesterol esters from HDL to… |
| D. | chylomicron remnants travel from the intestine within lymphatic fluid in the thoracic duct |
| E. | one half of all LDL molecules is taken up by macrophages and other cells by means other than the LDL receptor |
| Answer» C. lecithin cholesterol acyltrasferase is responsible for transferring cholesterol esters from HDL to… | |
| 59. |
Adrenal insufficiency may cause all but which of the following? |
| A. | inability to excrete a water load |
| B. | personality changes |
| C. | sodium loss with circulatory insufficiency |
| D. | hypoglycaemia in the presence of fasting |
| E. | leukocytosis |
| Answer» E. leukocytosis | |
| 60. |
Hyperaldosteronism: |
| A. | causes low plasmic Na+ and high H+ |
| B. | retains acid H+ ions and can cause acidosis |
| C. | doesn’t cause oedema due to the escape phenomenon |
| D. | may cause hypocalcaemic nephropathy |
| E. | may be caused by high sodium intake |
| Answer» C. doesn’t cause oedema due to the escape phenomenon | |
| 61. |
Bone: |
| A. | osteoblasts are multinucleate |
| B. | osteoclasts attach to bone via integins |
| C. | compact bone makes up 60% of a long bone |
| D. | osteoblasts secrete large quantities of type IV collagen and other bone matrix proteins |
| E. | oestrogens inhibit osteoblasts and stimulate osteoclasts |
| Answer» B. osteoclasts attach to bone via integins | |
| 62. |
Daily water turnover in the gastrointestinal tract: |
| A. | the stomach contributes about 2500ml resorption |
| B. | jejunum resorbs 1300ml of the water |
| C. | the colon absorbs the bulk of the water load |
| D. | the ??? toxin causes achenyl cyclase therefore ↑cAMP and ↑ Clsecretion, ↓ ??? |
| E. | stool balance (average) is 500ml |
| Answer» D. the ??? toxin causes achenyl cyclase therefore ↑cAMP and ↑ Clsecretion, ↓ ??? | |
| 63. |
Functional anatomy of the kidney – which is TRUE? |
| A. | 5 million nephrons in each human kidney |
| B. | pores in terestrated kidneys are 170-190nm in diameter |
| C. | mesengial cells are located between the basal lumina and podocytes |
| D. | glomerular membrane permits passage of small (???) neutral substances |
| E. | proximal tubule is 100nm long |
| Answer» D. glomerular membrane permits passage of small (???) neutral substances | |
| 64. |
Functional anatomy of the kidney – which is FALSE? |
| A. | total length of the nephrons ranges from 45-65mm |
| B. | the macula densa is ??? tubular epithelium of the collecting duct |
| C. | juxtaglomerular cells are found in the walls of the different arteriole |
| D. | intercolated cells are involved in acid secretion and bicarbonate transport |
| E. | total glomerular capillary endothelium across which filtration occurs, is 0.8m2 |
| Answer» B. the macula densa is ??? tubular epithelium of the collecting duct | |
| 65. |
Regulation of renal blood flow – which is FALSE? |
| A. | angiotensin II constricts the afferent arteriole and efferent arteriole |
| B. | noradrenaline constricts intertubular arteries and afferent arterioles |
| C. | dopamine causes vasodilation in renal vessels and natriuresis |
| D. | ACh – renal vasodilation |
| E. | prostaglandins increase blood flow to the cortex and decrease it in the medulla |
| Answer» A. angiotensin II constricts the afferent arteriole and efferent arteriole | |
| 66. |
All but which of the following cause contraction of the mesengial cells? |
| A. | endothelins |
| B. | angiotensin II |
| C. | ADH |
| D. | noradrenaline |
| E. | cAMP |
| Answer» E. cAMP | |
| 67. |
All but which of the following are involved in the movement of Na+/Cl- across the apical membrane of the proximal tubules? |
| A. | Na+ / 2Cl- / K+ co-transporter (CT) |
| B. | Na+/ glucose CT |
| C. | Na+/P??? CT |
| D. | Cl- / base exchanges |
| E. | Na+ / H+ exchanges |
| Answer» A. Na+ / 2Cl- / K+ co-transporter (CT) | |
| 68. |
B nerve fibres: |
| A. | provide motor supply to intrafusal muscle fibres |
| B. | are usually the first fibres affected by local anaesthetics |
| C. | are 12-20umol in diameter |
| D. | are unmyelinated |
| E. | provide pre-ganglionic autonomic supply |
| Answer» E. provide pre-ganglionic autonomic supply | |
| 69. |
Ionic: |
| A. | movement across an impermeable membrane occurs due to an osmotic gradient |
| B. | equilibrium potential can be determined using the Nernst equation |
| C. | movement across the capillary wall is not affected by the Donnan effect |
| D. | valency determines osmotic effect in an ideal solution |
| E. | forms of weak acids cross cell membranes easily |
| Answer» B. equilibrium potential can be determined using the Nernst equation | |
| 70. |
Steroid hormones: |
| A. | open ion channels in cell membrane |
| B. | act via cytoplasmic or nuclear receptors |
| C. | increase intracellular cAMP |
| D. | increase tyrosine kinase activity of transmembrane receptors |
| E. | act via a serpentine receptor |
| Answer» B. act via cytoplasmic or nuclear receptors | |
| 71. |
Cardiac muscle fibres: |
| A. | develop tetany only at very high stimulation frequencies |
| B. | develop less tension when stretched due to decreased actin-myosin overlap |
| C. | can derive only 5% of basal caloric requirement from fat |
| D. | have a T-system located at the A-I junctions |
| E. | remain absolutely refractory until the membrane potential repolarises to - 50mV |
| Answer» E. remain absolutely refractory until the membrane potential repolarises to - 50mV | |
| 72. |
Glomeruli: |
| A. | minimally filters protein, so plasma protein concentration is not altered |
| B. | are supplied by an extensive anastomotic arterial network |
| C. | lie distal to the juxtaglomerular apparatus |
| D. | each receive approximately 20-25% of resting cardiac output |
| E. | do not filter appreciable albumin since membrane pores are too small |
| Answer» C. lie distal to the juxtaglomerular apparatus | |
| 73. |
The distal tubule: |
| A. | absorbs most of the filtered sodium ions in the presence of aldosterone |
| B. | absorbs glucose in the normal state |
| C. | absorbs most of the filtered water in the presence of ADH |
| D. | secretes hydrogen via secondary active transport |
| E. | is almost entirely impermeable to urea |
| Answer» E. is almost entirely impermeable to urea | |
| 74. |
Regarding vitamin D metabolism: |
| A. | 25-hydroxycholecalciferol is converted to 1,25-dihydroxycholecalciferol in the distal convoluted tubule of the kidney |
| B. | 1,25-dihydroxycholecalciferol receptors can be found in skin |
| C. | when calcium levels are high, 24,25-dihydroxycholecalciferol levels are also high |
| D. | transport in plasma is by binding to haemoglobin |
| E. | formation of 25-hydroxycholecalciferol is tightly regulated |
| Answer» B. 1,25-dihydroxycholecalciferol receptors can be found in skin | |
| 75. |
Regarding protein metabolism: |
| A. | NH4 + is formed by reductive deamination of amino acids |
| B. | most of the body’s urea is formed in the kidney |
| C. | phosphorylcreatine is formed in the liver |
| D. | creatinuria occurs normally in children |
| E. | purines and pyrimidines are mainly sourced from dietary intake |
| Answer» D. creatinuria occurs normally in children | |
| 76. |
Which pattern of laboratory findings in the tale below is most consistent with a diagnosis of diabetes insipidis? 24 Hr Urine Volume Ketones Glucose Protein |
| A. | 4.0 + 0 0 |
| B. | 6.2 2+ 4+ 0 |
| C. | 1.6 0 0 4+ |
| D. | 6.4 0 0 0 |
| E. | 5.0 0 0 3+ |
| Answer» D. 6.4 0 0 0 | |
| 77. |
Angiotensin H causes: |
| A. | greater constriction of efferent than afferent arterioles |
| B. | greater constriction of afferent than efferent arterioles |
| C. | constriction of afferent arterioles only |
| D. | constriction of efferent arterioles only |
| E. | has no effect on arteriolar constriction |
| Answer» A. greater constriction of efferent than afferent arterioles | |
| 78. |
With regard to tuboglomerular feedback: |
| A. | the GFR increases when flow through the distal tubule increases |
| B. | the macula densa on the afferent arteriole is the sensor |
| C. | the afferent arteriole is constricted by thromboxane A2 |
| D. | it is designed to maintain Na+ reabsorption |
| E. | it does not operate in individual nephrons |
| Answer» C. the afferent arteriole is constricted by thromboxane A2 | |
| 79. |
With respect to the counter current system: |
| A. | the loops of Henle act as counter current exchanges |
| B. | solutes diffuse out of vessels conducting blood towards the cortex |
| C. | water diffuses out of ascending vessels |
| D. | water diffuses into the collecting ducts |
| E. | counter current exchange is passive and can operate even if counter current multiplication ceases |
| Answer» B. solutes diffuse out of vessels conducting blood towards the cortex | |
| 80. |
What is the clearance of a substance when its concentration in plasma is 1mg/ml, its concentration in urine is 10mg/ml and the urine flow is 2ml/min |
| A. | 2ml/min |
| B. | 10ml/min |
| C. | 20ml/min |
| D. | 200ml/min |
| E. | clearance cannot be determined from the information given |
| Answer» C. 20ml/min | |
| 81. |
Regarding the proximal tubule, the following statements are true EXCEPT: |
| A. | Na is co-transported out of the tubule with glucose |
| B. | Na is actively transported into the intercellular spaces by Na-K ATPase |
| C. | the cells are characterised by a brush border and tight junctions |
| D. | vasopressin increases the permeability to water by causing the rapid insertion of water channels into the luminal membrane |
| E. | water moves passively out of the tubule along osmotic gradients |
| Answer» D. vasopressin increases the permeability to water by causing the rapid insertion of water channels into the luminal membrane | |
| 82. |
With regard to the effect of hormones on renal tubules, which is CORRECT? |
| A. | aldosterone increases K reabsorption from the distal tubule |
| B. | angiotensin II increases H+ secretion from the proximal tubules |
| C. | ADH increases water reabsorption in the proximal tubule |
| D. | atrial naturetic peptide decreases Na+ reabsorption from the proximal tubules |
| E. | parathyroid hormone increases phosphate reabsorption |
| Answer» B. angiotensin II increases H+ secretion from the proximal tubules | |
| 83. |
The thin ascending loop of Henle is: |
| A. | relatively permeable to water |
| B. | relatively impermeable to Na+ |
| C. | permeable to both water and Na+ |
| D. | relatively impermeable to water |
| E. | relatively impermeable to both water and Na+ |
| Answer» D. relatively impermeable to water | |
| 84. |
Action potential initiation in the sinoatrial and atrioventricular nodes results from: |
| A. | Na+ influx |
| B. | K+ influx |
| C. | Ca++ influx |
| D. | Na+ and Ca++ influx |
| E. | increased K+ conductance |
| Answer» C. Ca++ influx | |
| 85. |
Regarding isometric ventricular reaction: |
| A. | it occurs late in diastole |
| B. | ventricular filling occurs |
| C. | intraventricular pressure remains constant during this phase |
| D. | it ends when the AV valve close |
| E. | it ends when the AV valve open |
| Answer» E. it ends when the AV valve open | |
| 86. |
Local vasoconstriction results from: |
| A. | increased potassium concentration |
| B. | increased magnesium concentration |
| C. | increased sodium concentration |
| D. | decrease in pH |
| E. | increased calcium concentration |
| Answer» E. increased calcium concentration | |
| 87. |
In compensated low output cardiac failure: |
| A. | venous resistance is decreased |
| B. | cardiac contractility is increased |
| C. | mean systemic filling pressure is decreased |
| D. | right atrial pressure is decreased |
| E. | venous return is decreased |
| Answer» D. right atrial pressure is decreased | |
| 88. |
With regard to ascending to high altitudes: |
| A. | there is a linear decrease in inspired oxygen pressures with increasing altitude |
| B. | the partial pressure of water vapour in moist inspired air decreases with PiO2 |
| C. | at 19,200m, barometric pressure = 47mmHg, PiO2 then is approx 9mmHg |
| D. | at peak at Mt Everest, barometric pressure = 380mmHg, PiO2 is approx 70mmHg |
| E. | in permanent residents of the Andes, arterial and venous PO2 is half normal levels |
| Answer» D. at peak at Mt Everest, barometric pressure = 380mmHg, PiO2 is approx 70mmHg | |
| 89. |
A 28-year-old lady has taken an overdose of sedatives causing her to hypoventilate. Given that her arterial PCO2 is now doubled to 80mmHg, which of the following is most likely to be correct, given that she is breathing room air at normal barometric pressures? |
| A. | arterial PO2 will be approximately 70mmHg |
| B. | arterial PO2 will be approximately 35mmHg |
| C. | arterial Hb O2 saturation will be approximately 50% |
| D. | arterial Hb O2 saturation will be approximately 80% |
| E. | arterial Hb O2 saturation will be approximately 27% |
| Answer» D. arterial Hb O2 saturation will be approximately 80% | |
| 90. |
Which of the following has the greatest effect on the ability of the blood to transport O2? |
| A. | the capacity of the blood to dissolve O2 |
| B. | the amount of Hb in the blood |
| C. | the pH of the plasma |
| D. | the CO2 content of red blood cells |
| E. | the temperature of the blood |
| Answer» B. the amount of Hb in the blood | |
| 91. |
The Haldane effect describes: |
| A. | the shift to the right of the O2 dissociation curve caused by increased PCO2 |
| B. | the enhanced loading of CO2 iii the presence of deoxygenated Hb |
| C. | the shift of chloride ions into red blood cells to balance HCO3 shift from those cells |
| D. | the action of carbonic anhydrase on carbonic acid |
| E. | none of the above |
| Answer» B. the enhanced loading of CO2 iii the presence of deoxygenated Hb | |
| 92. |
With regard to CO2 carriage in the blood: |
| A. | dissolved CO2 has an insignificant role in the carriage of CO2 in the blood |
| B. | HCO3 production is fast in plasma |
| C. | ionic dissociation of carbonic acid in the red cell is fast without an enzyme |
| D. | the CO2 concentration in blood is independent of the saturation of haemoglobin with oxygen |
| E. | the majority of CO2 is carried in the blood in the forms of dissolved CO2 and carbamino-compounds |
| Answer» C. ionic dissociation of carbonic acid in the red cell is fast without an enzyme | |
| 93. |
Substances cleared from the circulation by the lungs include all the following EXCEPT: |
| A. | angiotensin H |
| B. | serotonin |
| C. | leukotrienes |
| D. | bradykinin |
| E. | prostaglandin |
| Answer» A. angiotensin H | |
| 94. |
With regard to the normal Hb-ox-y-en dissociation curve, which is the most likely to be CORRECT? |
| A. | when arterial PO2 = 60mmHg, Hb saturation is ∼ 80% |
| B. | when arterial PO2 = 40mmHg, Hb saturation is ∼ 75% |
| C. | when arterial PO2 = 30mmHg, Hb saturation is ∼ 40% |
| D. | acidosis shifts the curve to the left |
| E. | decreased PCO2 shifts the curve to the right |
| Answer» B. when arterial PO2 = 40mmHg, Hb saturation is ∼ 75% | |
| 95. |
Increased lung compliance is associated with: |
| A. | increasing age |
| B. | increasing pulmonary venous pressure |
| C. | high expanding pressures |
| D. | interstitial fibrosis |
| E. | low lung volumes associated with hypoventilation |
| Answer» A. increasing age | |
| 96. |
The following physiological events that occur in the body are listed in random sequence:
|
| A. | a, b, c, d, e |
| B. | d, a, c, b, e, |
| C. | c, d, e, b, a, |
| D. | e, b, c, a, d, |
| E. | e, c, b, d, a |
| Answer» D. e, b, c, a, d, | |
| 97. |
In relation to acid base balance in the body: |
| A. | respiratory compensation in metabolic alkalosis is limited by carotid and aortic chemoreceptor response |
| B. | HCO3 concentration will decrease in compensated respiratory acidosis |
| C. | the rate of renal H+ secretion is not affected by PCO2 in respiratory acidosis |
| D. | chloride excretion is decreased in respiratory acidosis |
| E. | hepatic glutamine synthesis is decreased in chronic metabolic acidosis |
| Answer» A. respiratory compensation in metabolic alkalosis is limited by carotid and aortic chemoreceptor response | |
| 98. |
The action potential of a neuron: |
| A. | is initiated by efflux of Na+ |
| B. | is terminated by efflux of K+ |
| C. | declines in amplitude as it moves along the axon |
| D. | results in transient reversal of the concentration gradient of Na+ across the cell membrane |
| E. | is not associated with any net movement of Na+ or K+ across the cell membrane |
| Answer» B. is terminated by efflux of K+ | |
| 99. |
The functions of tropomyosin in skeletal muscle include: |
| A. | releasing Ca++ after an action potential |
| B. | sliding on actin to produce shortening |
| C. | binding to myosin during contraction |
| D. | acting as a “relaxing protein” at rest by covering up the sites where myosin binds to actin |
| E. | generating ATP which passes to the contractile mechanism |
| Answer» D. acting as a “relaxing protein” at rest by covering up the sites where myosin binds to actin | |
| 100. |
Regarding the autonomic nervous system: |
| A. | does not have a reflex like somatic nervous system |
| B. | has dopamine as the main transmitter |
| C. | has cholinergic division which increases activity of the intestinal musculature and increases gastric secretion |
| D. | neurotransmitter noradrenaline is metabolised by pseudocholinesterase |
| E. | is not involved with visceral sensation |
| Answer» C. has cholinergic division which increases activity of the intestinal musculature and increases gastric secretion | |
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