The Nervous System

Question 1

what is the functions of the nervous system?

Answer 1

control and communication

Question 2

3 basic functions?

Answer 2

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

Question 3

what composes the central nervous system?

Answer 3

brain and spinal cord

Question 4

what composes peripheral nervous system?

Answer 4

cranial nerves and spinal nerves

Question 5

functional division of the peripheral nervous system?

Answer 5

somatic, autonomic and enteric

Question 6

what is somatic nervous system?

Answer 6

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

Question 7

what is autonomic nervous system?

Answer 7

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

Question 8

what is enteric nervous system?

Answer 8

network of sensory and motor neurons in wall of GI tract

Question 9

the cell body of a neuron contains?

Answer 9

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

Question 10

dendrites contain?

Answer 10

nissl body, neurofibrils

Question 11

axon contain?

Answer 11

mitochondria, micotubules, neurofibrils

Question 12

axon begins at?

Answer 12

axon hillock

Question 13

structural classification of neurons?

Answer 13

multipolar, bipolar, unipolar

Question 14

what is multipolar neuron?

Answer 14

one axon many dendrites

Question 15

what is bipolar neuron?

Answer 15

one axon, one main dendrite

Question 16

what is unipolar?

Answer 16

one process, always sensory

Question 17

what are association neurons?

Answer 17

based on how they look or who described thenm first

Question 18

what are neuroglia?

Answer 18

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

Question 19

glia in CNS?

Answer 19

astrocytes, oligodendrocytes, microglia, ependymal cells

Question 20

glia in PNS?

Answer 20

schwann cell and satellite cells

Question 21

what is astrocytes?

Answer 21

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

Question 22

oilgodendrocytes?

Answer 22

forms myelin sheath

Question 23

ependymal?

Answer 23

forms membrane of epithelial tissue, produces CSF

Question 24

microglia?

Answer 24

macrophages (WBC), clean up dead neurons

Question 25

satellite cells?

Answer 25

support ganglia

Question 26

schwann cells?

Answer 26

myelin sheath on axon

Question 27

grey matter =

Answer 27

unmyelinated cell body

Question 28

white matter =

Answer 28

myelinated axons

Question 29

what are the electrical signals in neurons?

Answer 29

action potentials and local graded potentials

Question 30

membrane ion channels in neurons?

Answer 30

active (gated) channels and passive (leakage) channel

Question 31

what is active (gated) channels?

Answer 31

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

Question 32

what is leakage channel?

Answer 32

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

Question 33

what is hyperpolarization

Answer 33

more negative then resting potential of -70 mv

Question 34

what is depolarization?

Answer 34

membrane potential more positive

Question 35

what occurs in the resting state?

Answer 35

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

Question 36

what occurs in depolarization phase?

Answer 36

Na+ channel activation gates open Na+ rushing into cell

Question 37

what occurs in repolarization phase?

Answer 37

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

Question 38

what occurs in repolarization continue phase?

Answer 38

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

Question 39

what is propagated action potential?

Answer 39

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

Question 40

type of propagations?

Answer 40

continuous conduction, saltatory conduction

Question 41

what is continuous conduction?

Answer 41

slow occurs in unmyelinated fibers, one by one

Question 42

what is saltatory conduction?

Answer 42

occurs in myelinated fibers, faster

Question 43

Action potentials travel faster along?

Answer 43

larger diameter axons and myelinated axons

Question 44

A fibers are largest

Answer 44

myelinated somatic sensory fibers, motor fibers

Question 45

B fibers are medium

Answer 45

myelinated visceral sensory fibers, autonomic preganglionic fibers

Question 46

C fibers are smallest

Answer 46

unmyelinated sensory fibers