Nervous System Cells Flashcards Preview

BIO 109 Anatomy and Physiology II > Nervous System Cells > Flashcards

Flashcards in Nervous System Cells Deck (73)
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1
Q

Central Nervous System consists of (2):

A
  • Brain

- Spinal cord

2
Q

Structural and functional center of the nervous system that integrates sensory information

A

Central Nervous System

3
Q

Nerves that lie in “outer regions” of the nervous system

A

Peripheral Nervous System

4
Q

nerves that originate from the brain and brain stem (12 pairs)

A

cranial nerves

5
Q

nerves that originate from the spinal cord (31 pairs)

A

spinal nerves

6
Q

All incoming sensory pathways (northbound)

A

afferent division

7
Q

all outgoing motor pathways (southbound)

A

efferent division

8
Q

system that carries information to the skeletal muscle (or glands)

A

somatic motor division

9
Q

system that carries feedback information from skeletal muscle (or glands) to ____ integration centers in the CNS

A

somatic sensory division

somatic

10
Q

carries info to the visceral effectors (smooth and cardiac muscles and glands)

A

efferent division of autonomic nervous system

11
Q

carries feedback info to _____ integrating centers in the CNS

A

afferent/visceral sensory division

autonomic

12
Q

The autonomic nervous system is normally _____.

A

involuntary

13
Q

The somatic motor division is ____ and under conscious control.

A

voluntary

14
Q

2 subdivisions of efferent division of ANS:

A
  • sympathetic division

- parasympathetic division

15
Q

prepares the body for immediate threats to its internal environment (fight, flight, or freeze response)

A

sympathetic division

16
Q

coordinates body’s normal resting activities (rest and repair)

A

parasympathetic division

17
Q

2 main types of cells in the nervous system:

A
  • neurons

- glial cells (neuroglia)

18
Q

excitable cells that make nervous system functions possible. Form the “wiring” of the nervous system’s information circuits.

A

neurons

19
Q

cells that do not usually conduct information. They support the function of neurons in various ways.
(Helper cells)

A

glial cells (neuroglia)

20
Q

5 main types of glial cells:

A
  • astrocytes
  • microglia
  • ependymal cells
  • oligodendrocytes
  • schwann cells
21
Q

star-shaped, largest, and most numerous type of glial cell. They transfer nutrients from blood to the neurons, help recycle neurotransmitters at synapses, and form tight sheaths around brain capillaries

A

astrocytes

22
Q

double barrier made up of astrocytes and the endothelial cells that make the capillary walls

A

blood-brain barrier, BBB

23
Q

The ________ helps maintain a very stable environment required for normal functioning of the brain by forming a barrier that regulates passage of most ions between the blood and brain tissue.

A

Blood-Brain Barrier, BBB

24
Q

Some ions could disrupt the transmission of nerve impulses if _____ did not exist.

A

Blood-Brain Barrier, BBB

25
Q

small, usually stationary cells that engulf and destroy microorganisms and cellular debris. The “Macrophages” of the nervous system.

A

Microglia

26
Q

____ are usually quiet and inactive, but if brain tissue is inflamed or degenerating, they will enlarge and become mobile, allowing them to carry out phagocytosis.

A

Microglia

27
Q

cells that form thin sheets that line fluid-filled cavities in the CNS. Some take part in producing the fluid that fills these spaces. Some have motile cilia that help circulate fluid.

A

ependymal cells

28
Q

The fluid filled cavities in the CNS

A

ventricles

29
Q

smaller than astrocytes with fewer processes. They hold nerve fibers together and produce the myelin sheath around nerve fibers in CNS only

A

Oligodendrocytes

30
Q

cells found only in the PNS. They support nerve fibers and form myelin sheaths.

A

Schwann cells

31
Q

gaps in the myelin sheath

A

Nodes of Ranvier

32
Q

where the nucleus and cytoplasm are squeezed to perimeter. Essential in normal growth and regeneration.

A

Neurolemma

33
Q

special schwann cells that surround the cell body of a neuron, usually in ganglia

A

satellite cells

34
Q

excitable cells that initiate and conduct impulses to make all nervous system functions possible

A

neurons

35
Q

The 3 components of a neuron:

A
  • cell body
  • dendrites
  • axon
36
Q

AKA perikaryon or soma

A

cell body

37
Q
  • provides neurotransmitters needed for transmission of nerve signals
  • provides proteins for maintaining and regenerating nerve fibers
  • contains mitochondria, which are transported to end of axon
A

cell body

38
Q

cells that do not have a myelin sheath, and conduct nerve signals to the cell body of the neuron

A

dendrites

39
Q

Each neuron has one or more _____, which branch from the cell body

A

dendrites

40
Q

portion of the cell body from which the axon extends

A

axon hillock

41
Q

part of neuron that conducts nerve impulses away from the cell body of the neuron. Is sometimes covered by a myelin sheath

A

axon

42
Q

zone where dendrites and cell body receive stimulus and initiates impulse

A

Input zone

43
Q

zone where axon hillock collects all the nerve impulses arriving from the cell body and dendrites and decides whether to send the impulse any farther along the neuron

A

summation zone

44
Q

zone where the axon conducts the nerve impulse from the axon hillock all the way to the end of the neuron

A

conduction zone

45
Q

zone where telodendria and synaptic knobs (release neurotransmitters)

A

output zone

46
Q

The 3 structural classifications of neurons:

A
  • multipolar
  • bipolar
  • unipolar
47
Q

structural class: one axon and several dendrites

A

multipolar

48
Q

structural class: only one axon and one dendrite; least numerous kind of neuron

A

bipolar

49
Q

structural class: one process comes off neuron cell body but divides almost immediately into two fibers; central process and peripheral process

A

(pseudo)unipolar

50
Q

______ are always sensory

A

unipolar

51
Q

a signal conduction route to and from the CNS, with the electrical signal beginning in receptors and ending in effectors

A

reflex arc

52
Q

simplest form; consists of an aferrent neuron and an efferent neuron

A

two-neuron arc

53
Q

most common; consists of an afferent neuron, an interneuron, and an efferent neuron

A

three-neuron arc

54
Q

conduct impulses from afferent neurons to or toward motor neurons. They lie within CNS

A

Interneurons

55
Q

____ ____ are an example of regulatory feedback loop

A

Reflex arcs

56
Q

The location where nerve signals are transmitted from one neuron to another. Located at junction of synaptic knob of one neuron and dendrites or cell body of another neuron

A

synapse

57
Q

bundles of peripheral nerve fibers held together by several layers of connective tissue that form a sheath

A

nerves

58
Q

bundles of nerve fibers located within the CNS

A

tracts

59
Q

_____ : surrounds Schwann cell

A

endoneurium

60
Q

____ : surrounds a fascicle

A

perineurium

61
Q

____ : surrounds a whole nerve (and numerous fascicles and the blood vessels that supply them)

A

epineurium

62
Q

Most nerves in the nervous system are ____ ____, and contain both afferent and efferent fibers.

A

mixed nerves

63
Q

____ do not have connective tissue coverings.

A

tracts

64
Q

bundles of myelinated fibers

A

white matter

65
Q

made up of cell bodies and unmyelinated fibers

A

gray matter

66
Q

Gray matter: In the CNS bundles of cell bodies referred to as ____.

A

nuclei

67
Q

gray matter: In the PNS bundles of cell bodies referred to as ____.

A

ganglia

68
Q

____ have a limited capacity to repair themselves.

A

neurons

69
Q

Nerve fibers can be repaired if the damage is not extensive. The ____ and ____ have to be intact.

A

cell body, schwann cell

70
Q
  1. The distal portion of the axon and the myelin sheath regenerate
  2. Macrophages remove debris
  3. Remaining neurolemma and endoneurium form tunnel from the point of injury to the effector
  4. New schwann cells grow in the tunnel to maintain a path for regrowth of the axon
  5. cell body reorganizes itself to provide the necessary proteins to extend the remaining healthy portion of the axon
  6. axon sprouts appear.
  7. Skeletal muscle cell atrophies until the nervous connection is reestablished
A

Stages of nerve repair

71
Q

CNS neurons lack the _____: no tunnel to guide the repair from the point of injury

A

neurolemma

72
Q

____ fill the damaged areas and block regrowth within the CNS

A

astrocytes

73
Q

Most injuries to the ____ and ___ cause permanent damage.

A

brain, spinal cord