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Flashcards in Exam #4 extras Deck (73)
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1
Q

which pathways allow different parts of the nervous system to affect the activity of a neuron and when several neurons synapse with a smaller number of neurons?

A

convergent pathway

2
Q

which pathway allows one part of the nervous system to affect more than one part of the nervous system and a small number of neurons synapse with a larger number of neurons?

A

divergent pathway

3
Q

what is a reverberating circuit?

A

important functions that are periodically active such as sleep/wake cycle and respiration

4
Q

where is sodium concentration higher?

A

extracellular

5
Q

what is a nucleus

A

a cluster of cell bodies and their dendrites in the CNS

6
Q

what is a ganglion?

A

a cluster of cell bodies and their dendrites in the PNS

7
Q

what are some similarities between EPSPs and IPSPs? (3) (BCS)

A

1) both are graded potentials
2) conducted in a decremental fashion
3) size is proportional to the strength of the stimulus

8
Q

what ionic changes in the membrane will promote depolarization?

A

sodium and calcium

9
Q

are graded potentials reversable?

A

yes

10
Q

what is temporal summation?

A

a single synapse fires rapidly in sequence

11
Q

what is a IPSP?

A

when the hyperpolarization of a postsynaptic neuron occurs to a neurotransmitter

12
Q

why does hyperpolarization of a postsynaptic neuron occur with a IPSP?

A

because it is more likely to reach a threshold

13
Q

what are IPSPs due to?

A

the opening of chloride and potassium channels (hyperpolarization)

14
Q

what is the purpose of the absolute refractory period?

A

to prevent potentials from being generated in the reverse direction

15
Q

what is a plexus?

A

an extensive network of nerves outside the CNS

16
Q

during an action potential what is repolarization due to?

A

potassium ions leaving the cell

17
Q

which nerve fibers form the autonomic system?

A

B and C

18
Q

the propagation of action potentials from one node of ranvier to another along a myelenated axon

A

saltatory conduction

19
Q

what type of neurons are motor neurons and interneurons structurally?

A

multipolar

20
Q

what does gray matter primarily contain?

A

neuron cell bodies

21
Q

compared with the inside of the resting plasma membrane what is the outside surface of the membrane?

A

positively charged

22
Q

what are leak channels responsible for?

A

the ion permeability of the resting plasma membrane

23
Q

if the permeability of the plasma membrane to potassium increases what happens to the resting membrane potential difference and what is that called?

A

it increases and it’s called hyperpolarization

24
Q

what happens to the plasma membrane during repolarization?

A

potassium diffuses out of the cell

25
Q

what is occurring during the absolute refractory period? (2) (LP)

A

1) limiting of how many action potentials can be produced during a given time
2) prevention of an action potential from starting another action potential at the same time at the same point on the plasma membrane

26
Q

where are neurotransmitter substances stored in vessicles located?

A

in specialized portions of the axon

27
Q

in convergent pathways what does the response of the postsynaptic neuron depend on?

A

the summation of EPSPs and IPSPs

28
Q

what is the function of reciprocal innervation?

A

promotes relaxation of extensor muscles while opposing flexor muscles contract

29
Q

what do gamma motor neuron do?

A

they stimulate contraction of muscle spindles

30
Q

what do alpha motor neurons do?

A

stimulate muscle contraction

31
Q

what is a muscle spindle?

A

the sensory receptor of a stretch reflex

32
Q

which of the ramis for plexuses?

A

the ventral ramis

33
Q

what is the function of a crossed extensor reflex?

A

promotes relaxation of extensor muscles while opposing flexor muscles contract

34
Q

how many of each nerve are there?

A

8 cervical, 12 in the thoracic, 5 in the lumbar, 5 in the sacral and 1 in the coccygeal.

35
Q

whata kind of fibers (axons) does dorsal roots ONLY consist of?

A

sensory

36
Q

where do axons of sensory neurons synapse with cell bodies of interneurons?

A

in the posterior horn of spinal cord gray matter

37
Q

what is the possible reason for a reflex response accompanied by conscious sensation of pain?

A

divergent pathways

38
Q

what is responsible for regulating the sensitivity of the muscle spindle?

A

gamma motor neurons

39
Q

what is a collection of spinal nerves that join together after leaving the spinal cord called?

A

a plexus

40
Q

what are some characteristics of a dermatome? (3) (AEC)

A

1) area of skin supplied by a pair of spinal nerves
2) exists for each spinal nerve except C1
3) can be used to locate the site of spinal cord or nerve root damage

41
Q

what 2 nerves combined with the same sheath make up the sciatic nerve?

A

common fibular (peroneal) and tibial

42
Q

what would effect the damage to some afferent neurons of the PNS?

A

it would interfere with a person’s ability to sense a variety of stimuli.

43
Q

what are the basic functions of the cerebrum? (3)

A

1) controls conscious motor activity
2) controls thought
3) controls conscious perception

44
Q

what is the function of the brainstem?

A

it’s a critical center for essential survival reflexes and strong areas of destruction can be fatal

45
Q

what are the functions of the midbrain?

A

1) involved in maintaining muscle tone and coordinating movements
2) reflex movements of head, eyes and body towards visual, auditory or tactile stimuli
3) aids in unconscious regulation and coordination of motor activities

46
Q

what serves as a visual reflex center?

A

the midbrain

47
Q

which cranial nerve innervates skeletal muscles of the neck and back?

A

accessory (XI)

48
Q

which nerve is primarily a motor nerve with two branches; the spinal branch and the cranial branch

A

accessory (XI)

49
Q

which cranial nerves are only sensory

A

1, 2 and 8 (vestibulochlear)

50
Q

which cranial nerves are somatic motor and parasympathetic?

A

3

51
Q

which cranial nerves are somatic motor only?

A

4 (trochlear), 6 (abducens), 11 (accessory) and 12

52
Q

which cranial nerves are sensory and somatic motor?

A

5 (trigeminal)

53
Q

which cranial nerves are sensory, somatic motor and parasympathetic?

A

7 (facial), 9 (glossopharyngeal) and 10

54
Q

where in the brain is basal nuclei located?

A

1) midbrain
2) cerebrum
3) diencephalon

55
Q

what connects parts of the cerebrum to other parts of the brain and spinal cord?

A

projection fibers

56
Q

what connects areas of the cerebral cortex within the same hempisphere?

A

association fibers

57
Q

what structures connect the cerebellum to the brainstem and allow communication between the cerebellum and other parts of the CNS

A

the peduncles

58
Q

which cranial nerve is involved in reflexes necessary to maintain homeostasis?

A

vagus (X)

59
Q

what part of the diencephalon is directly connected to the pituitary gland?

A

the hypothalamus

60
Q

what area is located in the postcentral gyrus of the cerebral cortex?

A

the primary somatic sensory cortex

61
Q

what is it called when water-soluble molecules of the blood plasma move across the blood-brain barrier?

A

symport

62
Q

which nerves are involved in the sense of taste?

A

facial (VII), glossopharyngeal (IX) and vagus (X)

63
Q

what nerve has the greatest cutaneous sensory distribution of any of the cranial nerves?

A

trigeminal (V)

64
Q

what does the accessory nerve only have?

A

a spinal component

65
Q

where is the excess CSF returned to?

A

the venous circulation

66
Q

which portion of the spinal cord would be affected by a disease that damages myelin sheaths?

A

the white columns

67
Q

if a person with polio lost use of their leg, which area of their spinal cord would you expect the virus-infected motor cell neurons to be?

A

in the anterior grey horns

68
Q

what is the minimum number of neurons in a reflex arc?

A

2

69
Q

which part of the brain stem contain cranial nerves V and VI and a respiratory center?

A

pons

70
Q

where in the brain are basal nuclei located?

A

the cerebrum , medulla oblongata and midbrain

71
Q

what is part of the epithalamus?

A

the pineal gland and thalamus

72
Q

what is permeable across the BBB?

A

caffeine, glucose and oxygen

73
Q

what type of reflex arc are interneurons used?

A

polysynaptic

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