The Nervous System Flashcards Preview

Anatomy and Physiology1 > The Nervous System > Flashcards

Flashcards in The Nervous System Deck (46):
1

what is the functions of the nervous system?

control and communication

2

3 basic functions?

1. sensing change, 2. interpreting and remembering change 3. reacting to change

3

what composes the central nervous system?

brain and spinal cord

4

what composes peripheral nervous system?

cranial nerves and spinal nerves

5

functional division of the peripheral nervous system?

somatic, autonomic and enteric

6

what is somatic nervous system?

sensory neurons from somatic receptors to CNS and Motor neurons form CNS to muscle tissue

7

what is autonomic nervous system?

sensory from visceral organs to CNS, motor neurons to smooth muscle tissue, cardiac muscle and glands; sympathetic (fight), parasympathetic (stop)

8

what is enteric nervous system?

network of sensory and motor neurons in wall of GI tract

9

the cell body of a neuron contains?

nucleun, cytoplasm, nissl body, neurofilament, microtubules, lipofuscin pigment granules

10

dendrites contain?

nissl body, neurofibrils

11

axon contain?

mitochondria, micotubules, neurofibrils

12

axon begins at?

axon hillock

13

structural classification of neurons?

multipolar, bipolar, unipolar

14

what is multipolar neuron?

one axon many dendrites

15

what is bipolar neuron?

one axon, one main dendrite

16

what is unipolar?

one process, always sensory

17

what are association neurons?

based on how they look or who described thenm first

18

what are neuroglia?

supportive, protective, "nerve glue", smaller than neurons 50%, half the volume in CNS, capable of mitosis

19

glia in CNS?

astrocytes, oligodendrocytes, microglia, ependymal cells

20

glia in PNS?

schwann cell and satellite cells

21

what is astrocytes?

star-shaped, covers capillary, anchors neuron to capillary, metabolizes neurotransmitter, regulates Ca++ and K+, half neural tissue

22

oilgodendrocytes?

forms myelin sheath

23

ependymal?

forms membrane of epithelial tissue, produces CSF

24

microglia?

macrophages (WBC), clean up dead neurons

25

satellite cells?

support ganglia

26

schwann cells?

myelin sheath on axon

27

grey matter =

unmyelinated cell body

28

white matter =

myelinated axons

29

what are the electrical signals in neurons?

action potentials and local graded potentials

30

membrane ion channels in neurons?

active (gated) channels and passive (leakage) channel

31

what is active (gated) channels?

can be open/closed 1. voltage-gated 2. ligand-gated 3. mechanically-gated

32

what is leakage channel?

opens randomly, more K+ inside and Na++ outside

33

what is hyperpolarization

more negative then resting potential of -70 mv

34

what is depolarization?

membrane potential more positive

35

what occurs in the resting state?

Na+ channel closed and K+ channel closed, inactivation gate open activation gate closed

36

what occurs in depolarization phase?

Na+ channel activation gates open Na+ rushing into cell

37

what occurs in repolarization phase?

voltage gate K+ channel opens, Na+ channel inactivation gate closes, K+ leaves cell

38

what occurs in repolarization continue phase?

Na+ channel reset; inactivation gate reopens, K+ channel closed

39

what is propagated action potential?

the chances of Na+ travelling along axon and creating another action potential

40

type of propagations?

continuous conduction, saltatory conduction

41

what is continuous conduction?

slow occurs in unmyelinated fibers, one by one

42

what is saltatory conduction?

occurs in myelinated fibers, faster

43

Action potentials travel faster along?

larger diameter axons and myelinated axons

44

A fibers are largest

myelinated somatic sensory fibers, motor fibers

45

B fibers are medium

myelinated visceral sensory fibers, autonomic preganglionic fibers

46

C fibers are smallest

unmyelinated sensory fibers