McqMate
Chapters
1. |
With reference to the action potential: |
A. | decreasing the external Na+ concentration increases the size of the action potential |
B. | decreasing the external K+ concentration decreases the resting membrane potential |
C. | increasing the external Na+ concentration decreases the resting membrane potential |
D. | decreasing the external K+ concentration has little effect on the resting membrane potential |
E. | none of the above are true |
Answer» E. none of the above are true |
2. |
In the Erlanger and Gasser classification of nerve fibres: |
A. | C fibres have the fastest conduction velocity |
B. | Aγ fibres are responsible for touch and pressure |
C. | C fibres are most susceptible to local anaesthetics |
D. | Aα fibres have the fastest conduction velocity and the longest absolute refractory period |
E. | A fibres are most susceptible to hypoxia |
Answer» C. C fibres are most susceptible to local anaesthetics |
3. |
Regarding neurotrophins: |
A. | NGF and BDNF share the same receptor |
B. | the structure of the β subunit of NGF resembles that of insulin |
C. | CNTF is necessary for the growth and maintenance of sympathetic neurons |
D. | disruption of GDNF by gene knockout causes a marked loss of cutaneous mechanoreceptors |
E. | none of the above are true |
Answer» B. the structure of the β subunit of NGF resembles that of insulin |
4. |
Regarding cardiac muscle: |
A. | cardiac muscle has high ATPase activity |
B. | only the α MHC isoform is found in the atria |
C. | resting membrane potential is about -70mV |
D. | force of contraction is mediated by catecholamines acting via β1 -adrenergic receptors |
E. | mutations of the human ether-a-go-go gene causes minks to shake their legs uncontrollably |
Answer» D. force of contraction is mediated by catecholamines acting via β1 -adrenergic receptors |
5. |
Which of the following does not decrease smooth muscle membrane potential? |
A. | acetylcholine |
B. | stretch |
C. | cold |
D. | noradrenaline |
E. | parasympathetic stimulation |
Answer» D. noradrenaline |
6. |
In regard to plasma volume: |
A. | it contributes to 10% of body weight |
B. | can easily be measured by radioisotope chromium |
C. | if the plasma volume is known, the blood volume can be calculated by multiplying100-HCT/100 |
D. | measured by injecting Evans blue |
E. | the average plasma volume is 500ml |
Answer» D. measured by injecting Evans blue |
7. |
Which of the following is FALSE? |
A. | the ECF represents 20% of body weight |
B. | the blood volume represents 8% of the body weight |
C. | the 2/3 of the body water is in ICF |
D. | 18% of the body weight is protein |
E. | the transcellular fluids contribute to 5% of the body weight |
Answer» E. the transcellular fluids contribute to 5% of the body weight |
8. |
Which of the following is FALSE? |
A. | diffusion depends on concentration gradient of the solutes |
B. | osmotic pressure of a solution is inversely related to the volume of the solution |
C. | when 5% dextrose is infused, it becomes hypotonic to the plasma in the body |
D. | osmolality is defined as osmotically active particles in 1L of solution |
E. | osmolality is defined as a number of osmotically active particles in 1kg of solvent |
Answer» D. osmolality is defined as osmotically active particles in 1L of solution |
9. |
Regarding cell membrane, which of the following is FALSE? |
A. | the diameter of the cell membrane is about 7.5nm |
B. | 50% of the cell membrane is made up of proteins |
C. | the main lipids of the cell membrane are phospholipids |
D. | the hydrophilic ends of the lipid molecules are faced towards the interior of the cell membrane |
E. | the proteins in the cell membrane function as carriers, ion channels, enzymes and receptors |
Answer» D. the hydrophilic ends of the lipid molecules are faced towards the interior of the cell membrane |
10. |
Regarding mitochondria, which of the following is TRUE? |
A. | 99% of mitochondrial proteins are products of mitochondrial DNA |
B. | the outer membrane of the mitochondria is folded to form cristae |
C. | the space between the outer and inner mitochondrial space is called matrix space |
D. | it is the sperm which contributes to the formation of mitochondria in the zygote |
E. | the synthesis of ATP in the mitochondria is triggered by diffusion of H+ from matrix to intracristal space |
Answer» E. the synthesis of ATP in the mitochondria is triggered by diffusion of H+ from matrix to intracristal space |
11. |
Which is FALSE? |
A. | fast fibres have small number of mitochondria |
B. | fast fibres are called white muscles |
C. | the glycolic processes are more important in energy supply in fast fibres |
D. | slow fibres are also called red fibres |
E. | fast fibres have more extensive blood supply than slow fibres |
Answer» E. fast fibres have more extensive blood supply than slow fibres |
12. |
Smooth muscles differ from skeletal muscle by: |
A. | not having actin/myosin |
B. | not having striated appearance |
C. | not using ATP for contraction |
D. | not using Ca2+ for contraction |
E. | not having sarcoplasmic reticulum |
Answer» B. not having striated appearance |
13. |
Which of the following is absent in smooth muscle? |
A. | tropomysin |
B. | actin |
C. | myosin |
D. | troponin |
E. | mitochondria |
Answer» D. troponin |
14. |
The highest number of voltage gated Na+ channels are found in: |
A. | initial segment of axon |
B. | nodes of Ranvier |
C. | cell body |
D. | terminal buttons |
E. | myeline sheath |
Answer» A. initial segment of axon |
15. |
Which of the following nerve fibres is most susceptible to hypoxia? |
A. | group B |
B. | group C |
C. | group A – α |
D. | dorsal root |
E. | somatic motor |
Answer» A. group B |
16. |
Which of the following is most susceptible to pressure? |
A. | group A – motor |
B. | group C |
C. | group B |
D. | pre ganglionic-autonomic |
E. | muscle spindle fibres |
Answer» A. group A – motor |
17. |
Regarding nerve action potential, which is TRUE? |
A. | normal resting membrane potential is -40mV |
B. | initial rapid depolarisation is due to rapid influx of Ca2+ via fast channels |
C. | during depolarisation, Na+ permeality is greater than K+ permeality |
D. | hyperpolarisation is due to continuous opening of Na+ channels |
E. | plateau is formed by slow Ca2+ channels |
Answer» C. during depolarisation, Na+ permeality is greater than K+ permeality |
18. |
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» A. it always transports substances in one direction |
19. |
Which is TRUE? |
A. | steroids act via cAMP |
B. | insulin acts via IP3 |
C. | EGF+ erythropoietin act via cAMP |
D. | thyroid hormones act via G proteins |
E. | retinoic acid act via intracellular receptor → transcription of genes |
Answer» E. retinoic acid act via intracellular receptor → transcription of genes |
20. |
Na+ / K+ ATPase pump – which is FALSE? |
A. | it is electrogenic in nature |
B. | it is important in maintaining cell volume |
C. | plays a major role in secondary active transport |
D. | it is the main factor which determine the resting membrane potential |
E. | it is an example of primary active transport |
Answer» D. it is the main factor which determine the resting membrane potential |
21. |
Regarding serotonin: |
A. | the highest concentration is in the brain |
B. | formed by hydroxylation and decarboxylation of tyrosine |
C. | catabolised by COMT |
D. | some receptors are ion channels |
E. | mediates smooth muscle relaxation |
Answer» D. some receptors are ion channels |
22. |
GABA: |
A. | decreases Cl- conductance |
B. | is broken down by glutamate decarboxylase (GA????) |
C. | there are five receptor subtypes |
D. | benzodiazepines bind to the β subunit of the GABA receptor |
E. | is involved in 20% of CNS synapses |
Answer» E. is involved in 20% of CNS synapses |
23. |
Which is NOT present in high concentrations, at the active zone of synapses? |
A. | syntaxin |
B. | catecholamine vesicles |
C. | neuropeptide vesicles |
D. | synaptobrevin |
E. | calcium channels |
Answer» C. neuropeptide vesicles |
24. |
Which is not a ligand-gated ion channel? |
A. | nicotinic receptor |
B. | GABAA receptor |
C. | glycine receptor |
D. | NMDA receptor |
E. | 5-HT1 receptor |
Answer» E. 5-HT1 receptor |
25. |
Which drug is NOT involved in facilitating Cl- conductance? |
A. | benzodiazepines |
B. | progesterone |
C. | oestrogen |
D. | barbiturates |
E. | alcohol |
Answer» C. oestrogen |
26. |
Regarding skeletal muscle: |
A. | isotonic contraction does no work |
B. | calcium is released from troponin during contraction |
C. | the resting membrane potential is -70mV |
D. | treppe occurs in skeletal muscle only |
E. | white muscle has short twitch durations |
Answer» E. white muscle has short twitch durations |
27. |
Regarding cardiac muscle: |
A. | gap junctions provide high resistance bridges |
B. | T system of tubules located at A-I junctions |
C. | calcium binds to calmodulin |
D. | tetany is not possible due to the latch bridge mechanism |
E. | ↑cAMP leads to ↑ force of contraction |
Answer» E. ↑cAMP leads to ↑ force of contraction |
28. |
Regarding smooth muscle: |
A. | tropomyosin is absent |
B. | the resting membrane potential is -90mV |
C. | there is a highly developed sarcoplasmic reticulum |
D. | there are no spike potentials |
E. | dense bodies are attached to the cell membrane |
Answer» E. dense bodies are attached to the cell membrane |
29. |
Regarding synapses: |
A. | large vesicles contain ACh |
B. | Na+ influx triggers fusion / exocytosis of vesicles |
C. | I PSP can be produced by closing K channels |
D. | the synaptic cleft is 100-150nm |
E. | neurotransmitters migrate down the axon by fast axoplasmic transport |
Answer» E. neurotransmitters migrate down the axon by fast axoplasmic transport |
30. |
Regarding acetylcholine: |
A. | it is oxidised to choline and acetate by acetylcholinesterase |
B. | nicotinic receptors are blocked by atropine |
C. | it is the main excitatory transmitter in the spinal cord |
D. | it is secreted by the adrenal medulla |
E. | tetanus blocks its release at the NMJ |
Answer» E. tetanus blocks its release at the NMJ |
31. |
Regarding synaptic structure / function: |
A. | small clear vesicles in the presynaptic tunnel contain catecholamines |
B. | tetanus toxin causes spastic paralysis by blocking release of ACh at NMJ |
C. | chemical mediators located in ???? of presynaptic fibres contain one-way conduction of impulses |
D. | the EPSP is an all-or-none response |
E. | An I-PSP can be produced by localised increase in membrane permeability to Cl- |
Answer» C. chemical mediators located in ???? of presynaptic fibres contain one-way conduction of impulses |
32. |
Transmitters – all are true EXCEPT: |
A. | angiotensin II is a neurotransmitter of the polypeptidillars |
B. | glutamate is an inhibitory amino acid |
C. | glucagons is found in hypothalamus and retina |
D. | vasopressin is found in posterior pituitary, medulla, spinal cord |
E. | serotonin is an amine |
Answer» B. glutamate is an inhibitory amino acid |
33. |
Neurotransmitters: |
A. | atropine blocks effect of acetylcholine at ???? receptor |
B. | reaction between active acetate and choline is catalysed by acetylcholinesterase |
C. | nicotinic cholinergic receptors are serpentine receptors |
D. | the rate limiting step in synthesis of NOVA is ?????(concussion) of tyrosine to dopa |
E. | MAOA is found in nerve endings and platelets |
Answer» D. the rate limiting step in synthesis of NOVA is ?????(concussion) of tyrosine to dopa |
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