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Physiology MCQs 2004
1 With regards to the oxygen dissociation curve:
a) decrease in CO2 shifts the curve to the left
b) decrease in temperature shifts the curve to the left
c) increase in pH shifts the curve to the right
d) decrease in DPG shifts the curve to the right
e) carboxyhaemoglobin shifts the curve to the right
2 With regard to coronary circulation:
a) there are more people with a dominant right coronary artery than a left coronary
artery
b) the flow in all coronary arteries is greater in diastole
c) with exercise the O2 extraction of the blood increases markedly
d) inflammatory reaction plays no role in atherosclerosis which is mostly a
degenerative process
e) the average coronary blood flow is 20ml/min
3 Regarding calcium homeostasis:
a) distal renal tubular resorption is regulated by parathyroid hormone
b) 20% of renal reabsorption occurs in the proximal tubules
c) 90% of Ca2+ in blood is in a diffusable form
d) decreased serum calcium causes a decrease in parathyroid hormone
e) 80% of calcium is in the skeleton
4 V/Q ratio is:
a) 0.8 for the whole lung at rest
b) not affected by posture
c) reduced in PE
d) increased in areas of shunting
e) low at the apices which favors tuberculosis bacilli
Physiology MCQs (2004)
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5 With regard to cerebral circulation:
a) the cerebral blood flow is about 700ml/min
b) circumventricular organs have fenestrated capillaries and are outside the blood /
brain barrier
c) the anterior communicating artery comes off the middle cerebral artery
d) the cerebral spinal fluid flows from the subarachnoid space through the foramen
magendie and luschka
e) capillaries in the choroid plexus do not have gaps between the endothelial cells
6 Regarding O2 transport in blood:
a) O2 is transported by haemoglobin A, a 5 polypeptide chain protein globin
b) O2 is carried in three forms; dissolved, combined with haemoglobin and
combined with methaemoglobin
c) the O2 saturation of arterial blood with a PO2 of 40mmHg is about 85%
d) anaemia decreases O2 saturation
e) O2 affinity for Hb is reduced by decreased blood pH
7 Exercise:
a) increases heart rate due to increased cardiac sympathetic tone
b) involving isotonic muscle contraction causes increased heart rate and stroke
volume
c) decreases peripheral vascular resistance and increases systolic and diastolic
pressure
d) induced tachycardia can increase with age
e) increases the venous return and is the primary cause of increased cardiac output
8 In relation to lung volumes, which is TRUE?
a) vital capacity is measured as the amount of air inspired with a maximal
inspiratory effort
b) residual volume is the volume left after a maximal expiratory effort
c) the average tidal volume in men is 1 litre
d) FEV1 is the volume of air expired during the first second of passive expiration
e) the respiratory dead space is unaffected by pulmonary embolism
Physiology MCQs (2004)
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9 Which of the following is activated in the lung?
a) surfactant
b) prostaglandins
c) bradykinin
d) angiotensin
e) serotonin
10 Renal compensatory mechanisms for metabolic acidosis cause:
a) increased HCO3- excretion in urine
b) a drop in urine pH below 4.0
c) increased urinary excretion of NH4+
d) increased urinary excretion of HPO42e) increased urinary excretion of -betagluterate
11 At high altitude:
a) hyperventilation is primarily due to stimulation of the central chemoreceptors
b) polycythaemia can increase the O2 concentration of arterial blood to above
normal levels
c) the oxygen haemoglobin dissociation curve shifts to the right
d) pulmonary arterial pressure drops
e) renal excretion of HCO3- decreases
12 Regarding control of respiration:
a) the cerebral cortex has no effect on respiration
b) efferent neurons in the vagus regulate the depth of inspiration
c) afferent neurons from the proprioceptors affect the respiratory centre
d) O2 plays a major role linking the ventilation to metabolism
e) respiratory minute volume is inversely correlated to alveolar PCO2
13 In regard to oxygen uptake along the pulmonary capillary:
a) capillary pO2 approaches alveolar PO2 two thirds of the way along the capillary in
resting subjects
b) diffusion reserves of the lung are minimal
c) exhausting exercise at altitude causes increased O2 diffusion in normal subjects
d) O2 moves more slowly across the pulmonary capillary at altitude
e) pO2 in a red cell entering the pulmonary capillary is normally 60mmHg
Physiology MCQs (2004)
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14 If the O2 content of radial artery blood is 190ml/minute and the O2 content of
pulmonary artery blood is 90ml/minute and O2 consumption is 250ml/min, the
cardiac output is:
a) 5 L/minute
b) 2.5 L/minute
c) unable to be calculated
d) 0.4 L/minute
e) 4 L/minute
15 Cardiac output:
a) increases on the descending limb of Frank Starling curve
b) is unchanged in acidosis
c) is unchanged in transplanted hearts during exercise
d) increases with increased ventricular and diastolic pressure
e) is increased by quinidine
16 The vasomotor centre:
a) has a resting tonic discharge that is mediated through parasympathetic output
b) has a vasodilator area located in the upper medulla
c) exerts a purely excitatory action in the heart
d) will be inhibited by stimulation of the motor cortex
e) causes secretion of both adrenaline and noradrenaline from the adrenal medulla
17 Baroreceptors:
a) are located in the carotid bodies
b) discharge at a decreased rate when pressure rises
c) have afferent fibres with glutamate as an excitatory transmitter
d) are located in the adventitia of vessels
e) are reset in chronic hypertension to bring blood pressure back to normal
18 In the sinoatrial mode:
a) sympathetic stimulation causes hyperpolarisation
b) the resting membrane potential is –90mV
c) opening of the first Na channels produces the rapid upstroke of the AP
d) Influx of chloride ions causes hyperpolarisation after termination of the AP
e) slow Na/Ca channels are activated above the resting membrane potential
Physiology MCQs (2004)
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19 Lymph:
a) flow is about 6-8L per day
b) is initially carried in vessels which do not contain smooth muscle valves
c) is propelled primarily by skeletal muscle contraction
d) is made up of interstitial macromolecules endocytosed by endothelial cells
e) carries 80L of the total circulatory protein back to the circulation each day
20 Regarding Starling’s forces:
a) variations in capillary permeability are insignificant
b) the hydrostatic pressure gradient is never subatmospheric
c) in glomerular capillaries fluid moves out along almost their entire length
d) capillary hydrostatic pressure is increased by arteriolar vasoconstriction
e) oncotic pressure is inversely proportional to plasma albumin levels
21 Local mechanisms controlling blood flow include:
a) vasodilation secondary to adenosine release from cardiac muscle
b) vasoconstriction via release of prostacylin from platelets in injured cells
c) endothelin mediated smooth muscle constriction of arterioles > veins
d) vasoconstriction following histamine release
e) vasoconstriction secondary to decreased pCO2 and osmolality
22 Poiseuille’s law states that flow:
a) is inversely proportional to the pressure gradient
b) is proportional to viscosity
c) increases 8-fold when diameter is doubled
d) is not significantly affected by small changes in vessel calibre
e) is halved when vessel length is doubled
23 Which of the following statements about Starling’s Law of the heart is INCORRECT?
a) the decrease in developed tension at high degrees of stretch is not due to a
decrease in the number of cross bridges between actin and myosin
b) energy of contraction is inversely proportional to initial length of cardiac muscle
fibre
c) standing decreases cardiac muscle fibre length
d) force of contraction is increased by catecholamines without a change in muscle
length
e) increased total blood volume increases the length of cardiac muscle fibres
Physiology MCQs (2004)
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24 Regarding the cardiac cycle:
a) the mitral valve closes late in ventricular systole
b) during isovolumetric ventricular contraction, the aortic valve bulges into the
ventricle
c) peak right ventricular pressure is 40mmHg or less
d) the stroke volume at rest is 130mL per ventricle
e) right atrial systole precedes left atrial systole
25 Regarding fats:
a) the most abundant fat in the diet is cholesterol
b) lecithin is secreted by the pancreas to facilitate chain absorption
c) the most important enzyme for their digestion is pancreatic lipase
d) the hydrolysis of triglycerides is an irreversible process
e) larger quantities of short chain fatty acids, eg butterfat, are absorbed directly into
the portal blood
26 Which of the following substances is completely removed in the pulmonary
circulation:
a) vasopressin
b) dopamine
c) histamine
d) serotonin
e) prostaglandin A2
27 The major site of airways resistance is/are the:
a) trachea
b) large bronchi
c) medium sized bronchi
d) bronchioles
e) alveoli
28 Which of the following substances increases renal blood flow?
a) nitric oxide
b) adrenaline
c) endothelin
d) prostaglandins
e) angiotensin II
Physiology MCQs (2004)
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29 The role of secretin produced by the pancreas is:
a) neutralising the acid from the stomach
b) oxidising the acid from the stomach
c) increase the secretion of the digestive enzymes
d) decrease the secretion of digestive enzymes
e) breaking down fatty acids
30 Thyroid:
a) function is controlled by posterior pituitary stimulating hormone
b) function does not involved the production of calcitonin
c) gland capillaries are fenestrated
d) function can be maintained with a daily iodine intake of 50g
e) produced T3 and T4 is not metabolised
31 Regarding buffers in body fluids:
a) phosphate is the most important buffer in the blood
b) the pk of the bicarbonate buffer system is 7.1
c) haemoglobin in blood has six times the buffering capacity of the plasma proteins
d) protein and bicarbonate are the principal buffers in the CSF and urine
e) phosphate and bicarbonate are the principal intracellular buffers
32 With regard to osteomalacia:
a) demineralisation of the skeleton causes a fall in serum phosphate levels
b) the bones are stronger
c) vitamin D is converted by a two stage process into an active form in kidney
d) active vitamin D decreases intestinal absorption of calcium
e) increased plasma serum calcium stimulates parathyroid hormone secretion
33 Which of the following is activated by heat to regulate body temperature?
a) cutaneous vasoconstriction
b) shivering
c) hunger
d) cutaneous vasodilatation
e) increased secretion of norepinephrine and epinephrine
Physiology MCQs (2004)
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34 Regarding fluid volumes in the body:
a) plasma accounts for 8% of the body weight
b) the intracellular fluid accounts for 15% of the body’s weight
c) the interstitial fluid space can be directly measured
d) the ratio of total body water to body weight varies with the amount of fat present
e) intracellular fluid can be directly measured using dueterium oxide
35 In the visual pathways:
a) occipital lesions may spare macular areas of the visual field
b) fibres from the optic tract end in the medial geniculate nucleus
c) impulses from the left eye are relayed only to the right optic tract
d) the primary visual receiving area is in the frontal cortex
e) optic nerve fibres compose the innermost layer of the retina
36 In intercellular communication:
a) synaptic transmission involves transmission directly from cell to cell
b) paracrine transmission involves hormones and growth factors reaching cells via
circulating fluids
c) the same chemical messenger can function as a neurotransmitter, paracrine
mediator and as a neural hormone
d) messengers pass from cell to cell always entering extra cellular fluid
e) autocrine transmission involves binding of chemical messengers to receptors on
a different cell
37 During skeletal muscle contraction:
a) acetylcholine binds to muscarinic acetylcholine receptors
b) the endoplasic reticulum releases Ca2+
c) binding of Ca2+ to troponin-T uncovers the myosin binding sites on actin
d) Ca2+ reaccummulates via a voltage gated Ca2+ channel
e) the troponin-tropomyosin complex inhibits the interaction between actin and
myosin
38 Resting membrane potential:
a) is defined as negative outside and positive inside
b) is determined by relative permeability to sodium and potassium
c) in skeletal muscle has the same value as cardiac muscle membrane potential
d) has a slight excess of cations inside and anions outside the cell
e) is hyperpolarised in infarcted tissue
Physiology MCQs (2004)
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Physiology Answers (2004)
Ganong 21st Edition, unless otherwise stated
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
B
A
A
A
B
E
B
B
D
C
B
C
D
B
D
E
C
E
B
C
A
E
B
E
C
D
C
A
A
C
C
A
D
D
A
C
E
C
Pages
66 – 68
623 – 627
385 – 386
665
614 – 623
62 – 64
636
655
667 – 668
739
119 – 122
649 – 653
24 – 26
572
576 – 577
186 – 187
576 – 578
107 – 112
595
594
550
586 – 587
81, 574 – 575
567 – 570
756 – 760
43
94
224 – 225
286
320 – 321
735 – 738
911
257
2–3
151 – 153
35 – 36
64 – 65
8, 52, 56 and 541
Physiology MCQs (2004)
West 6th Edition
Wests 6th Edition
West, 6th Edition
Ganong, 20th Edition
West, 3rd Edition
Guyton, 10th Edition
Ganong, 19th Edition
Guyton, 10th Edition
Ganong, 19th Edition
Guyton, 10th Edition
West, 6th Edition
West, 6th Edition
Guyton
Guyton, 10th Edition
Ganong, 20th Edition
Ganong, 19th Edition
Ganong, 20th Edition
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