When considering fluid balance, which of the following is INCORRECT?

fluid intake and output may be altered in response to a change in extracellular osmolarity

the minimum daily fluid output may normally be estimated by measuring the urine output and adding 500ml

urine output is always the single largest contributor to fluid output

fluid intake and output may be altered in response to a change in extracellular osmolarity

fluid intake and output may be altered in response to a change in extracellular volume

the hypothalamus is an important regulator of fluid intake

Regarding heterotrimeric G proteins

They are not serpentine receptors

The delta unit separates from the other subunits to bring about the biological effect

The intrinsic GTPase activity of the alpha subunit converts GTP to GDP

They span the membrane seven times

is produced predominantly in the spleen in neonates

is produced in the juxtaglomerular cells of the kidney

production is stimulated by theophylline

secretion is facilitated by the acidosis that develops at high altitude

has a half-life in the circulation of about 5 hours

is produced predominantly in the spleen in neonates

Normal urinary values include all of the following EXCEPT:

specific gravity = 1.010 to 1.035

osmolality = 3 to 1400 millismol/litres

Regarding the function of the heart:

the pericardial sac normally contains about 50ml of fluid

at increased heart rates, diastole is shortened more than systole

the pericardial sac normally contains about 50ml of fluid

during the cardiac cycle, left ventricular ejection begins before right ventricular ejection

during expiration, the aortic valve closes before the pulmonary valve

the end diastolic ventricular volume is about 170ml

Regarding gas exchange in the lungs:

diffusing capacity of the lung for a gas is inversely proportionate to the surface area of the alveolocapillary membrane and directly proportional to its thickness

O2 is between N2O and CO but at rest, is perfusion limited

diffusing capacity of the lung for a gas is inversely proportionate to the surface area of the alveolocapillary membrane and directly proportional to its thickness

at rest, it takes blood 0.25secs to traverse the pulmonary capillaries

Inhibitory post synaptic potentials involve:

localised decrease in membrane permeability to K+

localised increase in membrane permeability to Na+

localised decrease in membrane permeability to Cl-

localised increase in membrane permeability to PO4

localised increase in membrane permeability to Cl-

localised decrease in membrane permeability to K+

With regard to the effect of hormones on renal tubules, which is CORRECT?

ADH increases water reabsorption in the proximal tubule

aldosterone increases K reabsorption from the distal tubule

angiotensin II increases H+ secretion from the proximal tubules

ADH increases water reabsorption in the proximal tubule

atrial naturetic peptide decreases Na+ reabsorption from the proximal tubules

parathyroid hormone increases phosphate reabsorption

With regard to the normal Hb-ox-y-en dissociation curve, which is the most likely to be CORRECT?

when arterial PO2 = 30mmHg, Hb saturation is 40%

when arterial PO2 = 60mmHg, Hb saturation is 80%

when arterial PO2 = 40mmHg, Hb saturation is 75%

when arterial PO2 = 30mmHg, Hb saturation is 40%

acidosis shifts the curve to the left

decreased PCO2 shifts the curve to the right

With regard to CO2 carriage in the blood:

the CO2 concentration in blood is independent of the saturation of haemoglobin with oxygen

dissolved CO2 has an insignificant role in the carriage of CO2 in the blood

HCO3 production is fast in plasma

ionic dissociation of carbonic acid in the red cell is fast without an enzyme

the CO2 concentration in blood is independent of the saturation of haemoglobin with oxygen

the majority of CO2 is carried in the blood in the forms of dissolved CO2 and carbamino-compounds

Regarding the vomiting reflex, which is INCORRECT?

it is integrated by the medilla

there are afferents from vestibular nuclei

With respect to the EEG and brain wave activity which is FALSE?

the frequency of the rhythm can be decreased with hypoglycaemia, hypothermia and increased ???

the rhythm (adults) has a frequency of 18-30/second

infants have a faster rhythm than adults

the frequency of the rhythm can be decreased with hypoglycaemia, hypothermia and increased ???

young adult 25% sleep is REM sleep

REM sleep is characterised by no muscle tone, but increased extraocular movement

All of the following are features of acclimatisation to high altitude EXCEPT:

shift to the right of the oxygen dissociation curve

increased number of capillaries in peripheral tissues

increased maximum breathing capacity

Considering conduction rates in myocardial cells, which statement is TRUE?

the duration of the action potential and refractory period in fast fibres is shorter than slow fibres

Perkinje fibres are subepicardial and are the largest fibres, 4-7 times the width of other fibres

Perkinje fibres are fast fibres , and can conduct a wave of depolarisation at a speed of 4m/sec

the duration of the action potential and refractory period in fast fibres is shorter than slow fibres

initial depolarisation occurs in fast fibres with a rapid influx of Ca2+ ions from the sarcoplasmic reticulum

none of the above statements are true

Regarding the heart, which is TRUE?

the left ventricle pump action is via reducing cross-sectional area, as a function of radius cubed

the right and left ventricles perform the same amount of work, because the same volume of blood is pumped by each

the cross sectional shape of both ventricles is approximately cylindrical

the right ventricle pumps by a bellows type mechanism

the left ventricle pump action is via reducing cross-sectional area, as a function of radius cubed

in pulmonary disease the right ventricle hypertrophies and assumes a crescented shape in cross section

Regarding buffers in the body

Initial correction of pH disturbance is achieved by the kidneys

The phosphate buffer system is the predominant buffer in the blood

Bones contribute to buffering by taking up bicarbonate

Hb is an important buffer in the blood

Regarding the neural control of breathing, which statement is INCORRECT?

inspiratory medullary neurons discharge spontaneously at a rate of 12-15 times/minute

medullary centres are close to but separate from central chemoreceptors

during quiet respiration, expiration is a passive event

inspiratory medullary neurons supply both phrenic nerves

ventral medullary neurons are expiratory and do not discharge spontaneously

inspiratory medullary neurons discharge spontaneously at a rate of 12-15 times/minute

Which of the following statements regarding erythropoietin is INCORRECT in an adult?

hypoxia can increase secretion within minutes

is secreted by spleen and salivary glands

is secreted in adequate amounts by liver in absence of kidneys

Regarding body fluid compartments

Plasma volume in a 70 kg male is approximately 5 litres

ECF / intracellular fluid volume ratio is larger in infants than in adults

Plasma volume in a 70 kg male is approximately 5 litres

A 30 year old male has 40% water as a percentage of body weight

Transcellular fluid has a greater volume than intracellular fluids

Which factor increases renal blood flow?

reduced systemic blood pressure

Coronary circulation:

at rest, heart extracts 50% O2 / unit of blood delivered

left coronary artery has greater flow in 50% of people

thebesian veins connect arterioles to the heart chambers

cusps of the aortic valve occlude orifices of coronary arteries during LV ejection

coronary flow at rest is 250ml/min

at rest, heart extracts 50% O2 / unit of blood delivered

Hypoxia at high altitudes:

causes severe symptoms in an unacclimatised person at 3,000m

can always be reversed with 100% O2

With regard to the metabolism of carbohydrates:

in the absence of liver glycogen stores, glycogen administration does not cause hyperglycaemia

glucocorticoids have a minor effect on gluconeogenesis

growth hormone causes increased use of glucose for energy

glucose is absorbed by most cells by active sodium glucose co-transport

during starvation, stores last for less than 24 hours

With regard to lipid metabolism:

only HDL is formed in the liver

fatty acids in the plasma form 1:1 complexes with albumin

plasma cholesterol levels rise considerably with an increase in daily ingestion

free fatty acids are metabolised in preference to glucose in a non-exercising individual

utilisation of fatty acids is stimulated by glucocorticoids

pH of a solution is the log to base 10 of the reciprocal hydrogen ion concentration

Is the negative log of the concentration of hydrogen ions

For each pH unit less than 7 the concentration of hydrogen ion is increased 10 fold

A pH of 7 is equal to a hydrogen ion concentration of 10-7 mmol/l

With respect to protein synthesis:

each amino acid found in human protein has its own individual single transfer RNA

pre mRNA processing occurs in the cytoplasm prior to binding to ribosomes on the endoplasmic retic???

each gene has regulatory, promoter, coding and non coding regions which are all transcribed into pre mRNA

introns no recognised physiological function

the promoter site of a gene is the site where RNA polymerase binds

With respect to the loop of Henle:

tubular fluid becomes concentrated as it passes through the ascending limb

the ascending limb is highly permeable to water

the descending limb is impermeable to water

the thick ascending limb co-transports sodium, potassium and chloride out of the lumen

tubular fluid becomes concentrated as it passes through the ascending limb

the ascending limb removes approximately 15% of filtered water

Renal blood pressure:

the pressure drop across the glomerulus is about 20mmHg

pressure in the renal vein is about 15mmHg

the glomerular capillary pressure is about 80% that of arterial

the greatest drop in pressure (percentage wise) is from the efferent arteriole to the peritubular capillary

Regarding movement to high altitude, which statement is INCORRECT?

hyperventilation occurs due to hypoxic stimulation of peripheral chemoreceptors

pro-erythroblasts mature into erythrocytes more rapidly than normal

renal bicarbonate excretion increases

increased numbers of mitochondria appear in the tissues

FiO2 decreases with increasing altitude

For transmembrane movement, which is TRUE?

Na+ -K+ -ATPase is an example of facilitated diffusion

exocytosis requires Ca2+ and energy

Na+ -K+ -ATPase is an example of facilitated diffusion

amiloride activates epithelial Na+ channels

clathrin is essential for vesicle exocytosis

water can only enter cells via water channels

The righting reflex is pronounced after sectioning of the neural axis above which level:

all above intact but decerebellate

In a polysynaptic reflex, which of the following happen when the strength of the adequate stimulus is increased?

the motor response spreads to include other muscles and even other limbs

the amplitude of the motor response is increased

the motor response spreads to include other muscles and even other limbs

there is increased inhibition of stretch reflexes

the duration of the motor response increases

Regarding muscle spindles:

all subtypes send afferents via flower spray ended 1a nerves

are composed of extrafusal fibres

all subtypes send afferents via flower spray ended 1a nerves

nuclear chain fibres show dynamic response

afferent discharge decreased with muscle stretch

Regulation of renal blood flow which is FALSE?

noradrenaline constricts intertubular arteries and afferent arterioles

angiotensin II constricts the afferent arteriole and efferent arteriole

noradrenaline constricts intertubular arteries and afferent arterioles

dopamine causes vasodilation in renal vessels and natriuresis

prostaglandins increase blood flow to the cortex and decrease it in the medulla

Regarding body temperature:

oral temperature is usually higher than rectal temperature

children have more precise temperature regulation

emotion has no effect on core temperature

The tympanic reflex :

is activated by foreign bodies in the external auditory canal

is activated by high-pitched sounds only

results in the decreased transmission of sound

Regarding compliance, which statement is INCORRECT?

functional residual capacity is the equilibrium volume when elastic recoil of lung is balanced by normal tendency for chest wall to spring out

hysteresis is due to frictional resistance to air movement

compliance is greater in expiration than in inspiration

compliance is increased in emphysema

compliance is a dynamic measure of lung and chest wall recoil

Temperature sensation:

warm receptors respond 30 - 100

respond to compartitive temp gradient ??? skin

warm receptors respond 30 - 100

afferents carried via the dorsal column

warm and cold afferents carried via Ad fibre

involves impulses being conducted from the muscle spindle to the motor cortex

is classically initiated by tapping on the quadriceps muscle

is initiated by stretch of the muscle

involves impulses being conducted from the muscle spindle to the motor cortex

involves extrafusal fibres stimulating annulospiral and flowerspray sensory fibres

involves gamma afferents of leksell

With regard to ascending to high altitudes:

in permanent residents of the Andes, arterial and venous PO2 is half normal levels

there is a linear decrease in inspired oxygen pressures with increasing altitude

the partial pressure of water vapour in moist inspired air decreases with PiO2

at 19,200m, barometric pressure = 47mmHg, PiO2 then is approx 9mmHg

at peak at Mt Everest, barometric pressure = 380mmHg, PiO2 is approx 70mmHg

in permanent residents of the Andes, arterial and venous PO2 is half normal levels

The thick ascending limb of the loop of Henle:

has maximal permeability to NaCl

is relatively permeable to water

is a site where there is no active transport of sodium

The thin ascending loop of Henle is:

relatively impermeable to both water and sodium ion

relatively impermeable to sodium ion

permeable to both water and sodium ion

relatively impermeable to water

relatively impermeable to both water and sodium ion

697 + Mcqs in Physiology in Biology Page 11 McqOptions

501.	Normal values for renal function include all of the following EXCEPT:
A.	filtration fraction =0.2
B.	22% of cardiac output
C.	GFR = 180 litres/day
D.	RPF = 900 litres/day
E.	Tm glucose = 450 mg/minute
Answer» F.

Discussion

502.	When considering fluid balance, which of the following is INCORRECT?
A.	the minimum daily fluid output may normally be estimated by measuring the urine output and adding 500ml
B.	urine output is always the single largest contributor to fluid output
C.	fluid intake and output may be altered in response to a change in extracellular osmolarity
D.	fluid intake and output may be altered in response to a change in extracellular volume
E.	the hypothalamus is an important regulator of fluid intake
Answer» C. fluid intake and output may be altered in response to a change in extracellular osmolarity

Discussion

503.	Regarding heterotrimeric G proteins
A.	GDP is bound to the B subunit
B.	They are not serpentine receptors
C.	The delta unit separates from the other subunits to bring about the biological effect
D.	The intrinsic GTPase activity of the alpha subunit converts GTP to GDP
E.	They span the membrane seven times
Answer» F.

Discussion

504.	Erythropoietin:
A.	is produced in the juxtaglomerular cells of the kidney
B.	production is stimulated by theophylline
C.	secretion is facilitated by the acidosis that develops at high altitude
D.	has a half-life in the circulation of about 5 hours
E.	is produced predominantly in the spleen in neonates
Answer» E. is produced predominantly in the spleen in neonates

Discussion

505.	Normal urinary values include all of the following EXCEPT:
A.	albumin 150mg/day
B.	pH = 4.5 to 8.0
C.	volume = 0.5 to 2.4 litres/day
D.	specific gravity = 1.010 to 1.035
E.	osmolality = 3 to 1400 millismol/litres
Answer» B. pH = 4.5 to 8.0

Discussion

506.	Regarding the function of the heart:
A.	at increased heart rates, diastole is shortened more than systole
B.	the pericardial sac normally contains about 50ml of fluid
C.	during the cardiac cycle, left ventricular ejection begins before right ventricular ejection
D.	during expiration, the aortic valve closes before the pulmonary valve
E.	the end diastolic ventricular volume is about 170ml
Answer» B. the pericardial sac normally contains about 50ml of fluid

Discussion

507.	Regarding gas exchange in the lungs:
A.	N2O is diffusion limited
B.	CO is perfusion limited
C.	O2 is between N2O and CO but at rest, is perfusion limited
D.	diffusing capacity of the lung for a gas is inversely proportionate to the surface area of the alveolocapillary membrane and directly proportional to its thickness
E.	at rest, it takes blood 0.25secs to traverse the pulmonary capillaries
Answer» D. diffusing capacity of the lung for a gas is inversely proportionate to the surface area of the alveolocapillary membrane and directly proportional to its thickness

Discussion

508.	The surface area of the lungs is:
A.	three times the area of skin
B.	ten times the area of skin
C.	30 times the area of skin
D.	100 times the area of skin
E.	none of the above
Answer» D. 100 times the area of skin

Discussion

509.	Inhibitory post synaptic potentials involve:
A.	localised increase in membrane permeability to Na+
B.	localised decrease in membrane permeability to Cl-
C.	localised increase in membrane permeability to PO4
D.	localised increase in membrane permeability to Cl-
E.	localised decrease in membrane permeability to K+
Answer» E. localised decrease in membrane permeability to K+

Discussion

510.	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» C. ADH increases water reabsorption in the proximal tubule

Discussion

511.	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» C. when arterial PO2 = 30mmHg, Hb saturation is 40%

Discussion

512.	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» D. the CO2 concentration in blood is independent of the saturation of haemoglobin with oxygen

Discussion

513.	Regarding the vomiting reflex, which is INCORRECT?
A.	it is integrated by the medilla
B.	breath is held in expiration
C.	the glottis closes
D.	it involves salivation
E.	there are afferents from vestibular nuclei
Answer» C. the glottis closes

Discussion

514.	Which drug is NOT involved in facilitating Cl- conductance?
A.	benzodiazepines
B.	progesterone
C.	oestrogen
D.	barbiturates
E.	alcohol
Answer» D. barbiturates

Discussion

515.	Which of the following does NOT increases synthesis of 2, 3-DPG?
A.	growth hormone
B.	phosphate deficiency
C.	thyroid hormone
D.	exercise for one hour
E.	androgens
Answer» C. thyroid hormone

Discussion

516.	With respect to the EEG and brain wave activity which is FALSE?
A.	the rhythm (adults) has a frequency of 18-30/second
B.	infants have a faster rhythm than adults
C.	the frequency of the 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» C. the frequency of the rhythm can be decreased with hypoglycaemia, hypothermia and increased ???

Discussion

517.	All of the following are features of acclimatisation to high altitude EXCEPT:
A.	shift to the right of the oxygen dissociation curve
B.	increased number of capillaries in peripheral tissues
C.	pulmonary vasodilation
D.	polycythaemia
E.	increased maximum breathing capacity
Answer» D. polycythaemia

Discussion

518.	Considering conduction rates in myocardial cells, which statement is TRUE?
A.	Perkinje fibres are subepicardial and are the largest fibres, 4-7 times the width of other fibres
B.	Perkinje fibres are fast fibres , and can conduct a wave of depolarisation at a speed of 4m/sec
C.	the duration of the action potential and refractory period in fast fibres is shorter than slow fibres
D.	initial depolarisation occurs in fast fibres with a rapid influx of Ca2+ ions from the sarcoplasmic reticulum
E.	none of the above statements are true
Answer» C. the duration of the action potential and refractory period in fast fibres is shorter than slow fibres

Discussion

519.	Regarding the heart, which is TRUE?
A.	the right and left ventricles perform the same amount of work, because the same volume of blood is pumped by each
B.	the cross sectional shape of both ventricles is approximately cylindrical
C.	the right ventricle pumps by a bellows type mechanism
D.	the left ventricle pump action is via reducing cross-sectional area, as a function of radius cubed
E.	in pulmonary disease the right ventricle hypertrophies and assumes a crescented shape in cross section
Answer» D. the left ventricle pump action is via reducing cross-sectional area, as a function of radius cubed

Discussion

520.	Regarding buffers in the body
A.	Initial correction of pH disturbance is achieved by the kidneys
B.	The phosphate buffer system is the predominant buffer in the blood
C.	Bones contribute to buffering by taking up bicarbonate
D.	Hb is an important buffer in the blood
E.	All of the above are true
Answer» E. All of the above are true

Discussion

521.	Regarding the neural control of breathing, which statement is INCORRECT?
A.	medullary centres are close to but separate from central chemoreceptors
B.	during quiet respiration, expiration is a passive event
C.	inspiratory medullary neurons supply both phrenic nerves
D.	ventral medullary neurons are expiratory and do not discharge spontaneously
E.	inspiratory medullary neurons discharge spontaneously at a rate of 12-15 times/minute
Answer» E. inspiratory medullary neurons discharge spontaneously at a rate of 12-15 times/minute

Discussion

522.	Which of the following statements regarding erythropoietin is INCORRECT in an adult?
A.	half-life of about 5 hours
B.	hypoxia can increase secretion within minutes
C.	is secreted by spleen and salivary glands
D.	is secreted in adequate amounts by liver in absence of kidneys
E.	is a glycoprotein
Answer» E. is a glycoprotein

Discussion

523.	Regarding body fluid compartments
A.	About 2/3 TBW is extracellular
B.	ECF / intracellular fluid volume ratio is larger in infants than in adults
C.	Plasma volume in a 70 kg male is approximately 5 litres
D.	A 30 year old male has 40% water as a percentage of body weight
E.	Transcellular fluid has a greater volume than intracellular fluids
Answer» C. Plasma volume in a 70 kg male is approximately 5 litres

Discussion

524.	Which factor increases renal blood flow?
A.	1 adrenergic stimulation
B.	2 adrenergic stimulation
C.	reduced systemic blood pressure
D.	exercise
E.	lying down
Answer» F.

Discussion

525.	Coronary circulation:
A.	left coronary artery has greater flow in 50% of people
B.	thebesian veins connect arterioles to the heart chambers
C.	cusps of the aortic valve occlude orifices of coronary arteries during LV ejection
D.	coronary flow at rest is 250ml/min
E.	at rest, heart extracts 50% O2 / unit of blood delivered
Answer» E. at rest, heart extracts 50% O2 / unit of blood delivered

Discussion

526.	Which of the following is inhibitory neurotransmitter?
A.	gallamine
B.	acetylcholine
C.	glutamate
D.	glycine
E.	aspartate
Answer» E. aspartate

Discussion

527.	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» B. serotonin

Discussion

528.	Hypoxia at high altitudes:
A.	is a form of stagnant hypoxia
B.	causes symptoms of cyanosis
C.	causes severe symptoms in an unacclimatised person at 3,000m
D.	can always be reversed with 100% O2
E.	increased H+ concentration
Answer» C. causes severe symptoms in an unacclimatised person at 3,000m

Discussion

529.	With regard to the metabolism of carbohydrates:
A.	in the absence of liver glycogen stores, glycogen administration does not cause hyperglycaemia
B.	glucocorticoids have a minor effect on gluconeogenesis
C.	growth hormone causes increased use of glucose for energy
D.	glucose is absorbed by most cells by active sodium glucose co-transport
E.	during starvation, stores last for less than 24 hours
Answer» F.

Discussion

530.	With regard to lipid metabolism:
A.	only HDL is formed in the liver
B.	fatty acids in the plasma form 1:1 complexes with albumin
C.	plasma cholesterol levels rise considerably with an increase in daily ingestion
D.	free fatty acids are metabolised in preference to glucose in a non-exercising individual
E.	utilisation of fatty acids is stimulated by glucocorticoids
Answer» F.

Discussion

531.	In regard to pH
A.	pH of a solution is the log to base 10 of the reciprocal hydrogen ion concentration
B.	Is the negative log of the concentration of hydrogen ions
C.	For each pH unit less than 7 the concentration of hydrogen ion is increased 10 fold
D.	A pH of 7 is equal to a hydrogen ion concentration of 10-7 mmol/l
E.	All of the above are true
Answer» F.

Discussion

532.	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» F.

Discussion

533.	With respect to the loop of Henle:
A.	the ascending limb is highly permeable to water
B.	the descending limb is impermeable to water
C.	the thick ascending limb co-transports sodium, potassium and chloride out of the lumen
D.	tubular fluid becomes concentrated as it passes through the ascending limb
E.	the ascending limb removes approximately 15% of filtered water
Answer» D. tubular fluid becomes concentrated as it passes through the ascending limb

Discussion

534.	Renal blood pressure:
A.	the pressure drop across the glomerulus is about 20mmHg
B.	pressure in the renal vein is about 15mmHg
C.	the glomerular capillary pressure is about 80% that of arterial
D.	the greatest drop in pressure (percentage wise) is from the efferent arteriole to the peritubular capillary
Answer» E.

Discussion

535.	Which of the following is NOT involved in the control of ventilation?
A.	peripheral chemoreceptors
B.	lung stretch receptors
C.	basal ganglia
D.	pons
E.	respiratory muscles
Answer» D. pons

Discussion

536.	Regarding movement to high altitude, which statement is INCORRECT?
A.	hyperventilation occurs due to hypoxic stimulation of peripheral chemoreceptors
B.	pro-erythroblasts mature into erythrocytes more rapidly than normal
C.	renal bicarbonate excretion increases
D.	increased numbers of mitochondria appear in the tissues
E.	FiO2 decreases with increasing altitude
Answer» F.

Discussion

537.	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» B. Na+ -K+ -ATPase is an example of facilitated diffusion

Discussion

538.	The righting reflex is pronounced after sectioning of the neural axis above which level:
A.	spinal cord
B.	medulla
C.	mid-brain
D.	subcortical nuclei
E.	all above intact but decerebellate
Answer» D. subcortical nuclei

Discussion

539.	In a polysynaptic reflex, which of the following happen when the strength of the adequate stimulus is increased?
A.	the amplitude of the motor response is increased
B.	the motor response spreads to include other muscles and even other limbs
C.	there is increased inhibition of stretch reflexes
D.	the duration of the motor response increases
E.	all of the above are true
Answer» B. the motor response spreads to include other muscles and even other limbs

Discussion

540.	Regarding muscle spindles:
A.	are composed of extrafusal fibres
B.	receive efferents
C.	all subtypes send afferents via flower spray ended 1a nerves
D.	nuclear chain fibres show dynamic response
E.	afferent discharge decreased with muscle stretch
Answer» C. all subtypes send afferents via flower spray ended 1a nerves

Discussion

541.	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» B. noradrenaline constricts intertubular arteries and afferent arterioles

Discussion

542.	Regarding body temperature:
A.	humans are poikilothermic
B.	oral temperature is usually higher than rectal temperature
C.	it is usually lowest at 6am
D.	children have more precise temperature regulation
E.	emotion has no effect on core temperature
Answer» F.

Discussion

543.	The tympanic reflex :
A.	is activated by foreign bodies in the external auditory canal
B.	results in vertigo
C.	is activated by high-pitched sounds only
D.	results in the decreased transmission of sound
E.	none of the above
Answer» E. none of the above

Discussion

544.	Regarding compliance, which statement is INCORRECT?
A.	functional residual capacity is the equilibrium volume when elastic recoil of lung is balanced by normal tendency for chest wall to spring out
B.	hysteresis is due to frictional resistance to air movement
C.	compliance is greater in expiration than in inspiration
D.	compliance is increased in emphysema
E.	compliance is a dynamic measure of lung and chest wall recoil
Answer» F.

Discussion

545.	The neurotransmitter secreted by primary afferent fibres for severe pain is:
A.	glutamate
B.	acetylcholine
C.	substance P
D.	opioid peptides
E.	noradrenaline
Answer» E. noradrenaline

Discussion

546.	Temperature sensation:
A.	respond to compartitive temp gradient ??? skin
B.	cold receptors predominate
C.	warm receptors respond 30 - 100
D.	afferents carried via the dorsal column
E.	warm and cold afferents carried via Ad fibre
Answer» C. warm receptors respond 30 - 100

Discussion

547.	The stretch reflex:
A.	is classically initiated by tapping on the quadriceps muscle
B.	is initiated by stretch of the muscle
C.	involves impulses being conducted from the muscle spindle to the motor cortex
D.	involves extrafusal fibres stimulating annulospiral and flowerspray sensory fibres
E.	involves gamma afferents of leksell
Answer» C. involves impulses being conducted from the muscle spindle to the motor cortex

Discussion

548.	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» E. in permanent residents of the Andes, arterial and venous PO2 is half normal levels

Discussion

549.	The thick ascending limb of the loop of Henle:
A.	is impermeable to water
B.	has maximal permeability to NaCl
C.	is relatively permeable to water
D.	is impermeable to NaCl
E.	is a site where there is no active transport of sodium
Answer» B. has maximal permeability to NaCl

Discussion

550.	The thin ascending loop of Henle is:
A.	relatively permeable to water
B.	relatively impermeable to sodium ion
C.	permeable to both water and sodium ion
D.	relatively impermeable to water
E.	relatively impermeable to both water and sodium ion
Answer» E. relatively impermeable to both water and sodium ion

Discussion

Explore topic-wise MCQs in Biology.

Normal values for renal function include all of the following EXCEPT:

When considering fluid balance, which of the following is INCORRECT?

Regarding heterotrimeric G proteins

Erythropoietin:

Normal urinary values include all of the following EXCEPT:

Regarding the function of the heart:

Regarding gas exchange in the lungs:

The surface area of the lungs is:

Inhibitory post synaptic potentials involve:

With regard to the effect of hormones on renal tubules, which is CORRECT?

With regard to the normal Hb-ox-y-en dissociation curve, which is the most likely to be CORRECT?

With regard to CO2 carriage in the blood:

Regarding the vomiting reflex, which is INCORRECT?

Which drug is NOT involved in facilitating Cl- conductance?

Which of the following does NOT increases synthesis of 2, 3-DPG?

With respect to the EEG and brain wave activity which is FALSE?

All of the following are features of acclimatisation to high altitude EXCEPT:

Considering conduction rates in myocardial cells, which statement is TRUE?

Regarding the heart, which is TRUE?

Regarding buffers in the body

Regarding the neural control of breathing, which statement is INCORRECT?

Which of the following statements regarding erythropoietin is INCORRECT in an adult?

Regarding body fluid compartments

Which factor increases renal blood flow?

Coronary circulation:

Which of the following is inhibitory neurotransmitter?

Substances cleared from the circulation by the lungs include all the following EXCEPT:

Hypoxia at high altitudes:

With regard to the metabolism of carbohydrates:

With regard to lipid metabolism:

In regard to pH

With respect to protein synthesis:

With respect to the loop of Henle:

Renal blood pressure:

Which of the following is NOT involved in the control of ventilation?

Regarding movement to high altitude, which statement is INCORRECT?

For transmembrane movement, which is TRUE?

The righting reflex is pronounced after sectioning of the neural axis above which level:

In a polysynaptic reflex, which of the following happen when the strength of the adequate stimulus is increased?

Regarding muscle spindles:

Regulation of renal blood flow which is FALSE?

Regarding body temperature:

The tympanic reflex :

Regarding compliance, which statement is INCORRECT?

The neurotransmitter secreted by primary afferent fibres for severe pain is:

Temperature sensation:

The stretch reflex:

With regard to ascending to high altitudes:

The thick ascending limb of the loop of Henle:

The thin ascending loop of Henle is: