are similar to other endothelial cells in the vascular tree

have a role in the control of GFR

are similar to other endothelial cells in the vascular tree

are responsible for tubuloglomerular balance

contract in response to dopamine

relax in response to vasopressin

Regarding the glomerulus filtration fx:

positively charged molecules pass more easily than neutral

it allows passage of molecules up to 4nm diameter freely, and up to 8nm with some difficulty depending on charge

positively charged molecules pass more easily than neutral

endothelial pores have a greater diameter than podocyte filtration slits

the basal lamina contains interruptions

Regarding the dorsal column:

receives efferents from contralateral stimuli

carries ipsilateral pain and temperature

ascends to the nuclei gracillis and ?????

receives efferents from contralateral stimuli

For the Erlanger and Gasser classification, which is TRUE?

C fibres have the largest diameter

Sunday morning syndrome mainly affects C fibres

local anaesthetics primarily affect A fibres

preganglionic autonomic fibres are type B

C fibres have the largest diameter

B fibres are the least susceptible to hypoxia

Nerve fibres, which is FALSE?

A and B fibres are all myelinated

70% of energy requirement of nerves is used in maintaining polarity across the recytlemina by action of Na-K ATPase

metabolic rate of nerves doubles in max action

C type fibres are non-myelinated and include some of the sympathetic preganglionic fibres

A and B fibres are all myelinated

effects of local anaesthetic are maximal in C fibres

When the cholinergic vagal fibres to nodal tissues are stimulated:

the membrane becomes hyper-polarised

the slope of the pre-potential is decreased

acetylcholine decreases conductance to Ca++ via muscarinic receptors

acetylcholine increases the permeability of nodal tissues to K+ via muscarinic receptors

provide motor supply to intrafusal muscle fibres

are usually the first fibres affected by local anaesthetics

provide pre-ganglionic autonomic supply

Dorsal root (type C) fibres:

are amongst the largest of the nerve fibres

are the fibres most susceptible to hypoxia

administration of lignocaine suppresses transmission in C fibres before affecting A fibres

In the Erlanger and Gasser classification of nerve fibres:

A fibres have the fastest conduction velocity and the longest absolute refractory period

C fibres have the fastest conduction velocity

A fibres are responsible for touch and pressure

C fibres are most susceptible to local anaesthetics

A fibres have the fastest conduction velocity and the longest absolute refractory period

A fibres are most susceptible to hypoxia

Which is FALSE regarding secondary active transport?

energy required is obtained by Na+ /K+ ATPase pump

it always transports substances in one direction

energy required is obtained by Na+ /K+ ATPase pump

a good example is Na+ / glucose co-transport

Na+ / Ca2+ antiport is an example of secondary active transport

secondary active transport occurs in renal tubules

With regard to diuretics:

antagonists to V2 vasopressin receptors act on the early portion of the distal convoluted tubule

frusemide acts on the thick ascending limb of the loop of Henle

antagonists to V2 vasopressin receptors act on the early portion of the distal convoluted tubule

thiazides act primarily on the thick ascending limb of the loop of Henle

loop diuretics act on the collecting ducts

aldosterone antagonists act on the early portion of the distal convoluted tubule

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

clearance cannot be determined from the information given

The Haldane effect describes:

the shift of chloride ions into red blood cells to balance HCO3 shift from those cells

the shift to the right of the O2 dissociation curve caused by increased PCO2

the enhanced loading of CO2 iii the presence of deoxygenated Hb

the shift of chloride ions into red blood cells to balance HCO3 shift from those cells

the action of carbonic anhydrase on carbonic acid

If [urine]PAH = 14mg/ml, urine flow = 0.9ml/min and [plasma]PAH = 0.02mg/mli) What is the clearance of PAH?ii) If the extraction ratio of PAH is 0.9, what is the renal blood flow (Hct=45%)?

ClPAH = 630, renal blood flow = 700mb/min

ClPAH = 630, renal blood flow = 1273ml/min

ClPAH = 630, renal blood flow = 700mb/min

ClPAH = 77, renal blood flow = 155mb/min

ClPAH = 777mb/min, renal blood flow = 1569mb/min

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?

clearance cannot be determined from the information given

Given that a person weighs 60kg and their haematocrit is 40%, their total blood volume is:

cannot be calculated with the given information

The stretch reflex in skeletal muscle:

is a feedback reflex aimed at maintaining muscle length

maintains muscle strength at various levels of muscle strength

is not elicited in the knee jerk which occurs after tapping

Regarding excitation-contraction coupling in skeletal muscle, which statement is INCORRECT?

troponin I tropomyosin complex constitutes a relaxing protein

calcium ions bind to troponin T

troponin I tropomyosin complex constitutes a relaxing protein

each cycle of attachment and detachment shortens muscle length by about 1%

ATP is the immediate source of energy

globular head of myosin II possesses actin binding site

Steps involved in skeletal muscle contraction include all of the following EXCEPT:

binding of acetylcholine to nicotinic receptors

increased Na+ and K+ conductance in end plate membrane

spread of depolarisation along T tubules

binding of calcium to troponin T, with uncovering of its actin-myosin binding site

Chemical composition, which is TRUE?

H2O and CO2 H2CO3 H+ and HCO3-, adding H+ shifts the equilibrium to the right, while adding ??? shifts it to the left

pH is the negative natural logarithm of [H+]

pH 5 to pH 6 involves tenfold increase in [H+]

pH remains 7.4 +/- 0.05 in ECF, stabilised by buffer

H2O and CO2 H2CO3 H+ and HCO3-, adding H+ shifts the equilibrium to the right, while adding ??? shifts it to the left

the Donnan effect does not contribute significantly to the balance of electrolyte between intra and extra vascular compartment

The role of calcium in excitation/contraction couple in skeletal muscle is:

by binding troponin I, it uncovers the binding site of actin to interact with the myosin head

by binding troponin C it uncovers the binding site of actin to interact with the myosin head

by binding troponin I, it uncovers the binding site of actin to interact with the myosin head

by binding to tropomyosin, it allows troponic to bind to myosin

by binding to troponin C, it allows the myosin head to disengage resulting in relaxation

it causes depolarisation to spread along the tubules

Tetanic contraction of skeletal muscle:

occurs only with isometric contractions

occurs because of the short refractory period of skeletal muscle

is due to increased calcium available for binding to troponin C

enables a tension development of approximately four times that of individual twitch contraction

occurs only with isometric contractions

has the same mechanism of that of cardiac muscle

Regarding aldosterone, which statement is INCORRECT?

it is only synthesised in the zona glomerulosa of the adrenal cortex

it responds to changes in plasma sodium more strongly than changes in plasma potassium

it is only synthesised in the zona glomerulosa of the adrenal cortex

its main action is to increase the synthesis of sodium-potassium pumps

angiotensins II and III have about equal mineralocorticoid stimulating activity

it acts via a cytoplasmic receptor that has equal affinity for cortisol

Diffusion is inversely proportional to:

the difference in partial pressure

square root of the molecular weight

the difference in partial pressure

The diffusion constant is proportional to:

square root of the molecular weight

difference in partial pressures

In the visual pathway:

binasal visual field fibres decussate at the opticchiasm

the lateral geniculate bodies are made up of t layers

fibres for reflex pupillary constriction leave the optic nerve at the optic chiasm

pituitary tumours can cause homonymous hemianopia

macular sparing may or may not occur with lesions in the geniculocalcanine tract

binasal visual field fibres decussate at the opticchiasm

When a visual stimulus falls on a given point in the retina for a long time:

there is adaptation in the visual cortex

the image becomes more clearly focused

there is adaptation in the visual cortex

the discharge rate in the bipolar cells increases

Which of the following affect visual activity?

contrast between stimulus and background

Regarding body composition

18% body weight is protein / related substances

15% body weight is interstitial fluid

Which statement regarding cardiac work is FALSE?

the higher resistance in smaller calibre vessels corresponds to greater energy losses

the energy applied to the blood stream is defined as kinetic plus potential

potential energy involves consideration of energy stored in elastic arterial walls and gravity

there is an exchange between kinetic and potential energy

the largest drop in energy occurs at the level of the precupillary sphincters

the higher resistance in smaller calibre vessels corresponds to greater energy losses

697 + Mcqs in Physiology in Biology Page 6 McqOptions

251.	Mesangial cells:
A.	have a role in the control of GFR
B.	are similar to other endothelial cells in the vascular tree
C.	are responsible for tubuloglomerular balance
D.	contract in response to dopamine
E.	relax in response to vasopressin
Answer» B. are similar to other endothelial cells in the vascular tree

Discussion

252.	Glucose reabsorption is most marked in which segment of the glomerulus?
A.	the proximal convoluted tubule
B.	the distal convoluted tubule
C.	the descending loop of Henle
D.	the ascending loop of Henle
E.	the collecting system
Answer» B. the distal convoluted tubule

Discussion

253.	Amino acid reabsorption is most marked in which segment of the glomerulus?
A.	the proximal convoluted tubule
B.	the distal convoluted tubule
C.	the descending loop of Henle
D.	the ascending loop of Henle
E.	the collecting duct
Answer» B. the distal convoluted tubule

Discussion

254.	Substance X is freely filtered by the glomerulus and is not reabsorbed, nor secreted nor metabolized.If - serum x concentration = 0.020 mg/mlrenal artery x concentration = 0.020 mg/mlrenal vein x concentration = 0.002 mg/mlurine x concentration = 14 mg/mlurine flow = 54 ml/hrlymphatic x concentration = 0.00001 mg/mlhaematocrit = 0.45Renal plasma flow is:
A.	10.5 ml/min
B.	630 ml/min
C.	700 ml/min
D.	11.7 ml/min
E.	21.2 ml/min
Answer» D. 11.7 ml/min

Discussion

255.	Substance X is freely filtered by the glomerulus and is not reabsorbed, nor secreted nor metabolized.If - serum x concentration = 0.020 mg/mlrenal artery x concentration = 0.020 mg/mlrenal vein x concentration = 0.002 mg/mlurine x concentration = 14 mg/mlurine flow = 54 ml/hrlymphatic x concentration = 0.00001 mg/mlhaematocrit = 0.45Then the CLEARANCE of X is:
A.	10.5 ml/min
B.	630 ml/min
C.	10.5 mg/min
D.	630 mg/min
E.	60 ml/min
Answer» C. 10.5 mg/min

Discussion

256.	Regarding the glomerulus filtration fx:
A.	it allows passage of molecules up to 4nm diameter freely, and up to 8nm with some difficulty depending on charge
B.	positively charged molecules pass more easily than neutral
C.	endothelial pores have a greater diameter than podocyte filtration slits
D.	the basal lamina contains interruptions
Answer» B. positively charged molecules pass more easily than neutral

Discussion

257.	Regarding the dorsal column:
A.	carries ipsilateral pain and temperature
B.	ascends to the nuclei gracillis and ?????
C.	receives efferents from contralateral stimuli
D.	sacral efferents lie laterally
E.	runs anteriorly in the cord
Answer» C. receives efferents from contralateral stimuli

Discussion

258.	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» D. C fibres have the largest diameter

Discussion

259.	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» D. A and B fibres are all myelinated

Discussion

260.	Triglycerides are transported to cells via:
A.	chylomicron remnants
B.	HDL
C.	LDL
D.	VLDL
E.	none of the above
Answer» E. none of the above

Discussion

261.	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» F.

Discussion

262.	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» F.

Discussion

263.	Dorsal root (type C) fibres:
A.	conduct proprioception
B.	are amongst the largest of the nerve fibres
C.	are the fibres most susceptible to hypoxia
D.	administration of lignocaine suppresses transmission in C fibres before affecting A fibres
E.	are myelinated
Answer» E. are myelinated

Discussion

264.	In the Erlanger and Gasser classification of nerve fibres:
A.	C fibres have the fastest conduction velocity
B.	A fibres are responsible for touch and pressure
C.	C fibres are most susceptible to local anaesthetics
D.	A fibres have the fastest conduction velocity and the longest absolute refractory period
E.	A fibres are most susceptible to hypoxia
Answer» D. A fibres have the fastest conduction velocity and the longest absolute refractory period

Discussion

265.	All of the following are transported across renal tubular cell membranes by secondary active transport, using the energy of the active transport of Na+ , EXCEPT:
A.	glucose
B.	lactate
C.	citrate
D.	H+
E.	K+
Answer» F.

Discussion

266.	Which of the following nerve fibres is most susceptible to hypoxia?
A.	group B
B.	group C
C.	group A
D.	dorsal root
E.	somatic motor
Answer» B. group C

Discussion

267.	The chemical agent that initiates impulses in pain fibres is:
A.	ATP
B.	substance P
C.	Ca2+
D.	H+
E.	K+
Answer» C. Ca2+

Discussion

268.	Which is FALSE regarding secondary active transport?
A.	it always transports substances in one direction
B.	energy required is obtained by Na+ /K+ ATPase pump
C.	a good example is Na+ / glucose co-transport
D.	Na+ / Ca2+ antiport is an example of secondary active transport
E.	secondary active transport occurs in renal tubules
Answer» B. energy required is obtained by Na+ /K+ ATPase pump

Discussion

269.	Substance X is freely filtered by the glomerulus and is not reabsorbed, nor secreted nor metabolized.If - serum x concentration = 0.020 mg/mlrenal artery x concentration = 0.020 mg/mlrenal vein x concentration = 0.002 mg/mlurine x concentration = 14 mg/mlurine flow = 54 ml/hrlymphatic x concentration = 0.00001 mg/mlhaematocrit = 0.45The GFR is:
A.	10.5 ml/min
B.	700 ml/min
C.	11.7 ml/min
D.	630 ml/min
E.	778 ml/min
Answer» E. 778 ml/min

Discussion

270.	With regard to diuretics:
A.	frusemide acts on the thick ascending limb of the loop of Henle
B.	antagonists to V2 vasopressin receptors act on the early portion of the distal convoluted tubule
C.	thiazides act primarily on the thick ascending limb of the loop of Henle
D.	loop diuretics act on the collecting ducts
E.	aldosterone antagonists act on the early portion of the distal convoluted tubule
Answer» B. antagonists to V2 vasopressin receptors act on the early portion of the distal convoluted tubule

Discussion

271.	Ethacrynic acid exerts its principle effect in the:
A.	proximal convoluted tubule
B.	descending loop of Henle
C.	thick ascending loop of Henle
D.	distal convoluted tubule
E.	collecting ducts
Answer» D. distal convoluted tubule

Discussion

272.	Renal acid secretion is enhanced by:
A.	respiratory acidosis
B.	respiratory alkalosis
C.	hyperkalaemia
D.	carbonic anhydrase inhibition
E.	collecting duct
Answer» B. respiratory alkalosis

Discussion

273.	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» D. 200ml/min

Discussion

274.	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» C. the shift of chloride ions into red blood cells to balance HCO3 shift from those cells

Discussion

275.	If [urine]PAH = 14mg/ml, urine flow = 0.9ml/min and [plasma]PAH = 0.02mg/mli) What is the clearance of PAH?ii) If the extraction ratio of PAH is 0.9, what is the renal blood flow (Hct=45%)?
A.	ClPAH = 630, renal blood flow = 1273ml/min
B.	ClPAH = 630, renal blood flow = 700mb/min
C.	ClPAH = 77, renal blood flow = 155mb/min
D.	ClPAH = 777mb/min, renal blood flow = 1569mb/min
Answer» B. ClPAH = 630, renal blood flow = 700mb/min

Discussion

276.	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» D. 200ml/min

Discussion

277.	What percentage of filtered sodium is reabsorbed by the kidney?
A.	1%
B.	93%
C.	99%
D.	50%
E.	100%
Answer» D. 50%

Discussion

278.	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» C. 4L

Discussion

279.	The cortical portion of the collecting duct has the capacity to reabsorb approximately 10% of the filtered water. Which substance is most important in regulating this effect?
A.	angiotensin II
B.	histamine
C.	vasopressin
D.	sodium
E.	prostaglandins
Answer» D. sodium

Discussion

280.	The stretch reflex in skeletal muscle:
A.	is a feedback reflex aimed at maintaining muscle length
B.	is a polysynaptic reflex
C.	maintains muscle strength at various levels of muscle strength
D.	is not elicited in the knee jerk which occurs after tapping
E.	none of the above are true
Answer» B. is a polysynaptic reflex

Discussion

281.	Regarding excitation-contraction coupling in skeletal muscle, which statement is INCORRECT?
A.	calcium ions bind to troponin T
B.	troponin I tropomyosin complex constitutes a relaxing protein
C.	each cycle of attachment and detachment shortens muscle length by about 1%
D.	ATP is the immediate source of energy
E.	globular head of myosin II possesses actin binding site
Answer» B. troponin I tropomyosin complex constitutes a relaxing protein

Discussion

282.	Steps involved in skeletal muscle contraction include all of the following EXCEPT:
A.	binding of acetylcholine to nicotinic receptors
B.	increased Na+ and K+ conductance in end plate membrane
C.	spread of depolarisation along T tubules
D.	binding of calcium to troponin T, with uncovering of its actin-myosin binding site
E.	CTP (cytidine triphosphate)
Answer» F.

Discussion

283.	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» D. H2O and CO2 H2CO3 H+ and HCO3-, adding H+ shifts the equilibrium to the right, while adding ??? shifts it to the left

Discussion

284.	The role of calcium in excitation/contraction couple in skeletal muscle is:
A.	by binding troponin C it uncovers the binding site of actin to interact with the myosin head
B.	by binding troponin I, it uncovers the binding site of actin to interact with the myosin head
C.	by binding to tropomyosin, it allows troponic to bind to myosin
D.	by binding to troponin C, it allows the myosin head to disengage resulting in relaxation
E.	it causes depolarisation to spread along the tubules
Answer» B. by binding troponin I, it uncovers the binding site of actin to interact with the myosin head

Discussion

285.	Which glucose transporter is responsible for the facilitated diffusion of glucose into pancreatic B cells?
A.	glut 1
B.	glut 2
C.	glut 3
D.	glut 4
E.	glut 5
Answer» C. glut 3

Discussion

286.	Tetanic contraction of skeletal muscle:
A.	occurs because of the short refractory period of skeletal muscle
B.	is due to increased calcium available for binding to troponin C
C.	enables a tension development of approximately four times that of individual twitch contraction
D.	occurs only with isometric contractions
E.	has the same mechanism of that of cardiac muscle
Answer» D. occurs only with isometric contractions

Discussion

287.	Fick s Law of Diffusion is dependent on all EXCEPT
A.	The posture of the subject
B.	The solubility of the gas
C.	Thickness of membrane barrier
D.	Molecular weight of the gas
E.	Area of the membrane
Answer» B. The solubility of the gas

Discussion

288.	Regarding aldosterone, which statement is INCORRECT?
A.	it responds to changes in plasma sodium more strongly than changes in plasma potassium
B.	it is only synthesised in the zona glomerulosa of the adrenal cortex
C.	its main action is to increase the synthesis of sodium-potassium pumps
D.	angiotensins II and III have about equal mineralocorticoid stimulating activity
E.	it acts via a cytoplasmic receptor that has equal affinity for cortisol
Answer» B. it is only synthesised in the zona glomerulosa of the adrenal cortex

Discussion

289.	Thiazide diuretics exert their main effect in the:
A.	proximal convoluted tubule
B.	descending loop of Henle
C.	thick ascending loop of Henle
D.	distal convoluted tubule
E.	collecting ducts
Answer» E. collecting ducts

Discussion

290.	Aldosterone has its principle effect in the:
A.	proximal convoluted tubule
B.	descending loop of Henle
C.	thick ascending loop of Henle
D.	distal convoluted tubule
E.	collecting ducts
Answer» F.

Discussion

291.	Which of these is NOT a factor affecting acid secretion?
A.	intracellular PCO2
B.	carbonic anhydrase level
C.	K+ concentration
D.	aldosterone concentration
E.	none of the above
Answer» F.

Discussion

292.	Diffusion is inversely proportional to:
A.	the diffusion constant
B.	tissue area
C.	solubility of the gas
D.	square root of the molecular weight
E.	the difference in partial pressure
Answer» E. the difference in partial pressure

Discussion

293.	The diffusion constant is proportional to:
A.	tissue thickness
B.	square root of the molecular weight
C.	difference in partial pressures
D.	tissue area
E.	gas solubility
Answer» F.

Discussion

294.	The visual cortex is situated at the:
A.	parieto-occipital sulcus
B.	cuneus
C.	calcanine fissure
D.	lateral geniculate body
E.	angular gyrus
Answer» E. angular gyrus

Discussion

295.	In the visual pathway:
A.	the lateral geniculate bodies are made up of t layers
B.	fibres for reflex pupillary constriction leave the optic nerve at the optic chiasm
C.	pituitary tumours can cause homonymous hemianopia
D.	macular sparing may or may not occur with lesions in the geniculocalcanine tract
E.	binasal visual field fibres decussate at the opticchiasm
Answer» E. binasal visual field fibres decussate at the opticchiasm

Discussion

296.	Which is the least significant buffering system in the blood?
A.	H+ + plasma protein HProt
B.	H+ +HPO4 2- H2PO4-
C.	H+ + HCO3 - H2CO3
D.	H+ + Hb HHb
E.	collecting duct
Answer» C. H+ + HCO3 - H2CO3

Discussion

297.	When a visual stimulus falls on a given point in the retina for a long time:
A.	the image becomes more clearly focused
B.	there is adaptation in the visual cortex
C.	the discharge rate in the bipolar cells increases
D.	the pupils constrict
E.	the image fades and disappears
Answer» B. there is adaptation in the visual cortex

Discussion

298.	Which of the following affect visual activity?
A.	cataracts
B.	vitamin A deficiency
C.	astigmatism
D.	contrast between stimulus and background
E.	all of the above
Answer» F.

Discussion

299.	Regarding body composition
A.	18% body weight is protein / related substances
B.	15% body weight is interstitial fluid
C.	60% body weight is water
D.	5% body weight is plasma
E.	All of the above are true
Answer» F.

Discussion

300.	Which statement regarding cardiac work is FALSE?
A.	the energy applied to the blood stream is defined as kinetic plus potential
B.	potential energy involves consideration of energy stored in elastic arterial walls and gravity
C.	there is an exchange between kinetic and potential energy
D.	the largest drop in energy occurs at the level of the precupillary sphincters
E.	the higher resistance in smaller calibre vessels corresponds to greater energy losses
Answer» E. the higher resistance in smaller calibre vessels corresponds to greater energy losses

Discussion

Explore topic-wise MCQs in Biology.

Mesangial cells:

Glucose reabsorption is most marked in which segment of the glomerulus?

Amino acid reabsorption is most marked in which segment of the glomerulus?

Regarding the glomerulus filtration fx:

Regarding the dorsal column:

For the Erlanger and Gasser classification, which is TRUE?

Nerve fibres, which is FALSE?

Triglycerides are transported to cells via:

When the cholinergic vagal fibres to nodal tissues are stimulated:

B nerve fibres:

Dorsal root (type C) fibres:

In the Erlanger and Gasser classification of nerve fibres:

All of the following are transported across renal tubular cell membranes by secondary active transport, using the energy of the active transport of Na+ , EXCEPT:

Which of the following nerve fibres is most susceptible to hypoxia?

The chemical agent that initiates impulses in pain fibres is:

Which is FALSE regarding secondary active transport?

With regard to diuretics:

Ethacrynic acid exerts its principle effect in the:

Renal acid secretion is enhanced by:

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

The Haldane effect describes:

If [urine]PAH = 14mg/ml, urine flow = 0.9ml/min and [plasma]PAH = 0.02mg/mli) What is the clearance of PAH?ii) If the extraction ratio of PAH is 0.9, what is the renal blood flow (Hct=45%)?

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?

What percentage of filtered sodium is reabsorbed by the kidney?

Given that a person weighs 60kg and their haematocrit is 40%, their total blood volume is:

The cortical portion of the collecting duct has the capacity to reabsorb approximately 10% of the filtered water. Which substance is most important in regulating this effect?

The stretch reflex in skeletal muscle:

Regarding excitation-contraction coupling in skeletal muscle, which statement is INCORRECT?

Steps involved in skeletal muscle contraction include all of the following EXCEPT:

Chemical composition, which is TRUE?

The role of calcium in excitation/contraction couple in skeletal muscle is:

Which glucose transporter is responsible for the facilitated diffusion of glucose into pancreatic B cells?

Tetanic contraction of skeletal muscle:

Fick s Law of Diffusion is dependent on all EXCEPT

Regarding aldosterone, which statement is INCORRECT?

Thiazide diuretics exert their main effect in the:

Aldosterone has its principle effect in the:

Which of these is NOT a factor affecting acid secretion?

Diffusion is inversely proportional to:

The diffusion constant is proportional to:

The visual cortex is situated at the:

In the visual pathway:

Which is the least significant buffering system in the blood?

When a visual stimulus falls on a given point in the retina for a long time:

Which of the following affect visual activity?

Regarding body composition

Which statement regarding cardiac work is FALSE?