01. CELL PHYSIOLOGY AND GENERAL PHYSIOLOGY OF EXCITABLE TISSUES

1. The concept of homeostasis:

a) refers to the unwavering control of a physiological set point;

b) refers to the 'all-or-none' law;

c) refers only to the regulation of body temperature;

d) refers to maintaining a stable external environment;

e) refers to maintaining physiological functions in a stable state.

E

2. Utilization time is:

a) the maximal time period for which a threshold stimulus should act, in order an AP to occur;

b) the duration of the depolarization phase of the AP;

c) the duration of the AP;

d) the duration of the absolute refractory period;

e) the minimal period of time for which a threshold stimulus should act, in order an AP to occur.

E

3. The highest lability has:

a) muscle cells;

b) nerve cells;

c) epithelial cells;

d) glial cells;

e) glandular cells.

B

4. Hormones:

a) are only with lipid structure;

b) may be secreted by exocrine glands;

c) may be secreted by nerve cells;

d) are used only in synapses;

e) are only with peptide structure.

C

5. For an action potential to occur:

a) the cell membrane must be in the absolutely refractory period;

b) K* influx must exceed Na+ efflux;

c) the cell membrane must be out of the relative refractory period;

d) the stimulus must reach or exceed threshold;

e) Cl influx must exceed K* efflux.

D

6. During the rising phase of the action potential:

a) voltage-gated K* channels close;

b) voltage-gated K* channels open;

c) voltage-gated N+ channels close;

d) voltage-gated Na+ channels open;

e) voltage-gated Cl channels open

D

7. The plasma membrane:

a) is permeable to lipophilic molecules;

b) is permeable to hydrophilic molecules;

c) may burst in hypertonic extracellular solutions;

d) cannot generate action potentials in excitable cells;

e) can generate action potentials in non-excitable cells.

A

8. Overcooling the nerve will cause:

a) increase of the threshold;

b) increase of the liability;

c) increase of the excitability;

d) decrease of the threshold

e) increased release of neurotransmitters.

A

9. The properties of local response:

a) 'all-or-none' law;

b) transmission with energy consumption;

c) summation;

d) transmission without energy consumption;

e) excitability is decreased.

C

10. The property of the living systems to react to changes of the external or the internal environment is called:

a) excitation;

b) excitability;

c) irritability;

d) action potential;

e) resting potential.

C

11. A less negative membrane potential means:

a) it is "less positive" than the resting potential;

b) it is closer to +20 mV;

c) the resting membrane potential is closer to the sodium equilibrium;

d) slight repolarization;

e) the cell cannot generate an action potential.

C

12. The membrane of a typical resting neuron is largely impermeable to:

a) Cl-;

b) K*;

c) Na+;

d) Ca2+;

e) Fe2+

C

13. The ion with the lowest intracellular concentration is:

a) Са2+

b) НСОз-;

c) Na+;

d) Mg2+;

e) K*.

A

14. The blockers of the calcium ion channels are called:

a) calcium agonists;

b) calcium binding proteins;

c) calcium receptors;

d) calcium antagonists;

e) calcium binding lipids.

D

15. Which of the following requires energy?

a) diffusion;

b) osmosis;

c) facilitated diffusion;

d) active transport;

e) filtration.

D

16. The most common intracellular cation is:

a) calcium;

b) sodium;

c) magnesium;

d) phosphorus;

e) potassium.

E

17. Most appropriate solution for intravenous infusion is:

a) hypertonic NaCI solution;

b) hypotonic NaCI solution;

c) isotonic NaCI solution;

d) distilled water;

e) ionized water.

C

18. What is the normal pH value of the body fluids?

a) 7.35-7.45;

b) 7.15-7.25;

c) 7.55 - 7.65;

d) 7.00-7.35;

e) 6.5-7.5.

A

19. Which of the following is not found in the cell membrane?

a) galactose;

b) phospholipids;

c) proteins;

d) cholesterol;

e) nucleic acids.

A

20. The main structural elements in the cell membrane are:

a) proteins;

b) phospholipids, cholesterol, and proteins;

c) carbohydrates;

d) cholesterol;

e) nucleic acids.

B

21. The local response is:

a) a potential that is generated as a result of the action of a sub- threshold stimulus and propagated along the nerve cell membrane;

b) a potential that is generated as a result of the action of a sub- threshold stimulus and could be registered only at the site of

irritation;

c) a potential that is generated as a result of the action of a super- threshold stimulus and propagated along the nerve cell membrane;

d) a potential that is generated on the postsynaptic membrane as a result of the action of a neurotransmitter;

e) a potential that is generated as a result of the action of a super- irritation.

threshold stimulus and could be registered only at the site of irritation.

B

22. Norepinephrine is a neurotransmitter with the highest affinity to:

a) N-cholinergic receptors;

b) B-adrenergic receptors;

c) a- and ß-adrenergic receptors;

d) a-adrenergic receptors;

e) M-cholinergic receptors.

D

23. The oculocardiac reflex is an example of:

a) somato-somatic reflex;

b) viscero-somatic reflex;

c) somato-visceral reflex;

d) viscero-visceral reflex;

e) integrated conditioned reflex.

C

24. The parasympathetic postganglionic neurons of the ANS secrete:

a) norepinephrine (98%) and epinephrine (2%);

b) epinephrine (80%) and norepinephrine (20%);

c) L-DOPA;

d) norepinephrine (2%) and epinephrine (98%);

e) acetylcholine.

E

25. A structure that permits an excitable cell to pass an electrical or

chemical signal to another cell (neural or otherwise) with excitatory or

inhibitory effects, is called:

a) juxtaglomerular apparatus;

b) synapse;

c) intercalated disc;

d) Golgi apparatus;

e) modulator.

B

26. The critical (firing) level of depolarization is:

a) a level of AP at which depolarization goes into repolarization.

b) a level of AP at which repolarization goes into depolarization.

c) a degree of depolarization of the postsynaptic membrane, at which further action of the neurotransmitter is abolished.

d) a degree of depolarization of the excitable membrane at which its intensity does not depend on irritant action.

e) a degree of depolarization of the nerve cell membrane at which its sources of energy are completely exhausted.

D

27. H1-receptors are situated on the smooth muscle cell membrane of the:

a) gastrointestinal tract;

b) bronchi;

c) urinary tract;

d) uterus;

e) blood vessels.

B

28. The Horveg-Weiss curve represents:

a) the intensity/duration relationship of the threshold stimulus;

b) the phases of the AP;

c) the conduction of the excitation through myelinated nerve fiber;

d) the intensity/duration relationship of the subthreshold stimulus;

e) the conduction of the excitation through unmyelinated nerve iber.

A

29. The adrenergic effect on the cardiac conduction system and working myocardium is exercised by affecting:

a) M-choline receptors;

b) a1-receptors;

c) B1-receptors;

d) a2-receptors;

e) B2-receptors.

C

30. The parasympathetic spinal centers, regulating the reservoir functions,

are situated in the following segments:

a) C8-Th1;

b) S2-S4;

c) Thi0-L2;

d) Th1-Th8;

e) L2-L4.

B

31. Facilitated diffusion is a mechanism:

a) that works with the help of a carrier in the membrane;

b) for transporting substances against their concentration gradient;

c) connected with membrane polarity;

d) associated with loss of energy;

e) for transporting lipid soluble substances through the membrane.

A

32. The diffusion through the phospholipid layer of the cellular membrane

is possible for:

a) lipophilic substances;

b) only for oxygen and carbon dioxide;

c) hydrophilic substances;

d) lipophobic substances;

e) only for water.

A

33. A distinguishing feature of the membrane potential at rest is:

a) high permeability for K+ ions;

b) low permeability for Na and high for K* ions;

c) low permeability for Cl- ions;

d) the small difference between the equilibrium potentials for Na+, and

K† ions;

e) low permeability for Na+.

B

34. The common expression of excitation is:

a) membrane transport;

b) muscle cell contraction;

c) nerve cell conduction and excitation;

d) glandular cell secretion;

e) the action potential;

E

35. Acetylcholine is a neurotransmitter which has:

a) always an excitatory effect on the postsynaptic membrane;

b) always an inhibitory effect on the postsynaptic membrane;

c) excitatory or inhibitory effect depending on the amount released;

d) excitatory or inhibitory effect on the postsynaptic membrane

depending on the type of receptors;

e) no effect on the postsynaptic membrane.

D

36. An example of a ligand dependent membrane is:

a) the axon membrane;

b) the postsynaptic membrane;

c) the nodes of Ranvier;

d) the skeletal muscle T-tubule membrane;

e) the axon hillock.

B

37. Curare is a substance that blocks:

a) M-cholinergic receptors;

b) a-adrenergic receptors;

c) N-cholinergic receptors in neuromuscular synapses;

d) B-adrenergic receptors;

e) all types of cholinergic receptors.

C

38. Which statement for the electrical synapses is true:

a) they are unidirectional;

b) the information is transmitted bidirectionally;

c) the synaptic cleft is bigger than in chemical synapses;

d) the transmission of the information is slower;

e) they can be controlled.

B

39. Throughout the relative refractory period:

a) the excitability becomes equal to zero;

b) the excitability is equal to that at rest;

c) the excitability is higher than that at rest;

d) the excitability is lower than that at rest;

e) accommodation occurs.

D

40. Na/K pump is called electrogenic, because it: a) exports equal amount of Na, and K;

b) imports equal amount of Na* and K+;

c) exchanges equal amount of Na and K;

d) imports Na, and exports K;

e) the exchanged amount of Na, and K is not equal.

E

41. The conditioned reflexes are:

a) formed on the basis of unconditioned reflexes;

b) inborn;

c) permanent;

d) typical of the species;

e) not individual.

A

42. Excitability is a property of:

a) nerve, muscle, and some endocrine cells;

b) all cells in the body;

c) only nerve cells;

d) only muscle cells;

e) only endocrine cells.

A

43. Which of the statements is not true:

a) at the chemical synapse transmission of excitation is one way;

b) the velocity of transmission of excitation is higher at the chemical synapses than at the electrical ones;

c) at most of the electrical synapses transmission is two-way;

d) the velocity of transmission of excitation is greater at the electrical synapses than at the chemical ones;

e) when there is continuous excitation at a synapse, fatigue occurs.

B

44. Which is the basic inhibitory neurotransmitter in CNS:

a) glutamate;

b) GABA;

c) neuropeptide Y;

d) substance P;

e) nitric oxide.

B

45. Which of the following transmitters does not bind with a membrane

receptor, to fulfil its effect:

a) glutamate;

b) serotonin;

c) dopamine;

d) histamine;

e) nitric oxide.

E

46. The basic factor for the ion asymmetry on both sides of the excitable

membrane is:

a) Ca2+ pump and the low permeability for Na+;

b) Na+ pump and the low permeability for Na+;

c) iodine pump;

d) K* pump and the high permeability for Na+;

e) Na+/K* pump and the low permeability for Na+.

E

47. The velocity of AP propagation along the axon membrane depends on:

a) the strength of irritation;

b) the cross-sectional area of the axon;

c) the duration of irritation;

d) the direction of its propagation;

e) the threshold.

B

48. Saltatory conduction:

a) occurs only in myelinated fibers;

b) has a faster velocity in cold than in warm conditions;

c) is slower than non-saltatory conduction in nerve fibers with diameters around 10 um;

d) transmits impulses with a velocity proportional to fibers length;

e) occurs only in non-myelinated fibers.

A

49. The result of activated o-adrenergic receptors is:

a) relaxation of the gastrointestinal tract smooth muscles and

contraction of the sphincters;

b) increased heart rate;

c) constriction of the vessels smooth muscle;

d) dilation of the vessels smooth muscle and relaxation of the uterus;

e) constriction of the bronchi smooth muscles.

C

50. Intracellular depot for Ca2* ions is:

a) mitochondria;

b) endoplasmic reticulum;

c) microtubules;

d) Golgi's apparatus;

e) nucleus.

B

51. The result of activated a2-adrenergic receptors is:

a) increased heart rate;

b) constriction of the vessels smooth muscle;

c) relaxation of the gastrointestinal tract smooth muscles and contraction of the sphincters;

d) dilation of the vessels smooth muscle and relaxation of the uterus;

e) constriction of the bronchi smooth muscles.

C

52. Secretion of more than one transmitter by a neuron is called:

a) habituation;

b) cotransmition;

c) sensitisation;

d) perception;

e) inhibition.

B

53. Protein synthesis occurs at the:

a) ribosomes;

b) lysosomes;

c) within the nucleus;

d) mitochondria;

e) vacuoles.

A

54. During repolarization of the cell membrane:

a) Na+ move inside of the cell;

b) Na+ move outside of the cell;

c) K+ move outside of the cell;

d) K* move inside of the cell;

e) Cl- move outside of the cell.

C

55. Movement of solvent and dissolved substances across a cell

membrane by hydrostatic pressure is:

a) osmosis;

b) facilitated diffusion;

c) filtration;

d) simple diffusion;

e) active transport.

C

56. In a cell, movement of molecules from an area of low concentration to an area of high concentration:

a) uses facilitated diffusion;

b) requires cellular energy;

c) is passive transport;

d) requires both cellular energy and facilitated diffusion;

e) uses its concentration gradient to move.

B

57. Cell membranes:

a) are formed entirely by protein molecules;

b) are impermeable to fat soluble substances;

c) are not changed throughout life;

d) in some tissues permit transport of glucose at a greater rate in the presence of insulin;

e) are permeable to water soluble substances.

D

58. The substance acetylcholine is released from synaptic vesicles by the process of:

a) phagocytosis;

b) simple diffusion;

c) passive transport;

d) endocytosis;

e) exocytosis.

E

59. Inhibitory postsynaptic potentials (IPSP) can be generated by:

a) opening of calcium channels;

b) closing of potassium channels;

c) opening of sodium channels;

d) opening of chlorine channels;

e) closing of chlorine channels.

D

60. Proteins that are secreted by cells are generally:

a) not synthesized on ribosomes that are bound to endoplasmic reticulum;

b) packed in the Golgi apparatus;

c) synthesized in the mitochondria;

d) across the cell membrane by endocytosis;

e) synthesized in the lysosomes.

B

61. Transmission across a synapse is dependent on the release of?

a) hormones;

b) synaptic vesicle;

c) neurons;

d) receptor proteins;

e) neurotransmitters.

E

62. The unique feature in mitochondria is:

a) myosin;

b) DNA;

c) actin;

d) prothrombin;

e) hemoglobin.

B

63. An example of co-transport is:

a) Na+ glucose transport;

b) Ca++ pump;

c) Na+- H† pump;

d) Na+-K* pump;

e) Na/Ca pump.

A

64. The resting membrane potential of a cell:

a) is equal to the equilibrium potential of Na*;

b) falls to zero if Na+/K* ATP-ase in the membrane is inhibited;

c) is equal to the equilibrium potential for K+;

d) is dependent on the permeability of the cell membrane to K being greater to Na;

e) is equal to the equilibrium potential of CI-.

D

65. Mitochondria:

a) are the chief site of lipid synthesis;

b) are the chief site of protein synthesis;

c) are more numerous in white than in brown fat cells;

d) are the chief sites for generation of ATP;

e) are absent near the membranes of actively secreting cells.

D

66. For the endoplasmic reticulum it is not true that:

a) it is a complex system of intracellular tubules;

b) it has a membrane structure similar to the cell membrane;

c) it is associated with ribonucleoprotein;

d) it is well developed in secretory cells;

e) it stores sodium ions.

E

67. The mammalian cell membrane:

a) is seen as an optically dense line using light microscopy;

b) consists mainly of protein;

c) contains enzymes DNA;

d) is more permeable to fat- than to water-soluble particles;

e) contains the receptors for steroid hormones.

D

68. Which of the following is an example for active transport:

a) filtration;

b) osmosis;

c) simple diffusion;

d) ATP binding cassette;

e) facilitated diffusion.

D

69. An action potential in a nerve fiber:

a) occurs when its membrane potential is hyperpolarized to a critical level;

b) is associated with a transient decrease in membrane permeability to potassium;

c) is associated with a transient increase in membrane permeability to sodium;

d) induces local response;

e) has an amplitude which varies directly with the strength of stimulus.

C

70. Which of the following receptors controls the ion permeability of the

postsynaptic membrane by a direct pathway:

a) ß-adrenergic receptors;

b) N-cholinergic receptors;

c) receptors for serotonin;

d) a-adrenergic receptors;

e) M-cholinergic receptors.

B

71. EPSP can be generated by:

a) closing of sodium-potassium channels;

b) closing of sodium channels;

c) opening of chlorine channels;

d) closing of potassium channels;

e) closing of sodium-potassium-calcium channels.

D

72. The conduction velocity of a nerve impulse can be determined by

which of the following factors?

1. temperature; 2. diameter of axon; 3. stimulus frequency; 4. myelin sheath; 5. stimulus strength:

a) 1, 3, 5 and 4;

b) 1, 2 and 3;

c) 3 and 1;

d) 4, 2 and I;

e) 3 and 2.

D

73. The junction between one neuron and the next, or between a neuron

and an effector is called:

a) a dendrite;

b) a synapse,

c) a neurotransmitter;

d) a ventricle;

e) none of the above.

B

74. The vesicular transport from the cell to the extracellular environment is called:

a) endocytosis;

b) exocytosis;

c) pinocytosis;

d) phagocytosis;

e) apoptosis.

B

75. Which of the following blocks acetylcholine receptor sites causing muscle relaxation?

a) novocaine;

b) nicotine;

c) curare;

d) nerve gases;

e) carbon monoxide.

C

76. The nerve center of the pharyngeal reflex, manifested with urge to vomit, is located in:

a) the midbrain;

b) the spinal cord;

c) the medulla oblongata;

d) the limbic system;

e) the cerebral cortex.

C

77. The elements of the reflex arc do not include:

a) receptor;

b) conducting pathways;

c) nerve center;

d) effector;

e) stimulus.

E

78. The most important element of the reflex are is:

a) receptor;

b) conducting pathways;

c) nerve center;

d) effector;

e) all are equally important.

E

79. Electroneurography (ENG) is:

a) the method for recording the bioelectrical activity of the brain;

b) the method for recording the bioelectrical activity of peripheral nerve fibers;

c) the method for recording the bioelectrical activity of the myocardial cells;

d) the method for recording the bioelectrical activity of glial cells;

e) the method for recording the bioelectrical activity of spinal cord.

B

80. The innervation of the adrenal medulla is carried out by:

a) postganglionic cholinergic fibers;

b) preganglionic cholinergic fibers;

c) preganglionic adrenergic fibers;

d) postganglionic adrenergic fibers;

e) preganglionic dopaminergic fibers.

B

81. The ability to generate action potential without external irritation is called:

a) automaticity;

b) accommodation;

c) acclimatization;

d) absolute refractory period;

e) ambivalent effect.

A

82. The minimum time required for a stimulus with the strength of two rheobases to generate an action potential is called:

a) utilization time;

b) rheobase;

c) chronaxie;

d) threshold of irritation;

e) time constant.

C

83. Which of the following types of nerve fibers has the slowest conduction

velocity?

a) A⍺;

b) Aß;

c) С;

d) B;

e) А∂.

C

84. The main mechanism involved in the formation of short-term memory is:

a) convergence;

b) divergence;

c) the formation of reverberating circles in the brain;

d) generalization;

e) encephalization.

C

85. General manifestation of the excitation is:

a) contraction of the muscle cell;

b) action potential;

c) conduction through nerve cells;

d) secretion by glandular cells;

c) motion.

B

86. Secondary messengers are:

a) substances that bind to membrane receptors;

b) substances that mediate the intracellular response;

c) hormones that are formed in the cell in response to its stimulation;

d) substances which are outside the cell and modulate the strength of the cellular response;

e) substances which create new cellular functions.

B

87. The cellular response is not determined by:

a) the type of receptors on the cell membrane;

b) the location of the synapse in the body;

c) the number of the second messenger molecules;

d) the number of the activated intracellular kinases;

c) the number of the receptors on the cell membrane.

B

88. Which is not an element of the chemical synapse:

a) presynaptic membrane;

b) connexon;

c) postsynaptic membrane;

d) synaptic cleft;

e) vesicles with neurotransmitters.

B

90. Which of the following types of nerve fibers has the fastest conduction

velocity?

a) A⍺;

b) Aß;

c) С;

d) B;

e) А∂.

A

89. Which statement is not true for electrical synapses:

a) the transmission of the information is faster in comparison with chemical synapses;

b) the transmission of the information is facilitated by

neurotransmitters;

c) the transmission of the information is bidirectional;

d) the transmission of the information happens trough a connexon;

e) they are also called gap junctions.

B