Nervous System for Exam 2

Question 1

list the 6 components of the central nervous system

Answer 1

1. gray matter
2. white matter
3. spinal cord
4. cauda equina
5. meninges
6. cerebrospinal fluid

Question 2

describe gray matter

Answer 2

groups of cell bodies (nuclei) around brain and in center of spinal cord

Question 3

describe white matter

Answer 3

groups of myelinated axons (tracts) inside of brain and on the outside of the spinal cord

Question 4

describe the function of spinal axons (in white matter)

Answer 4

transmit and receive signals from the brain

Question 5

list the 4 main components of the brain

Answer 5

1. cerebrum
2. cerebellum
3. interbrain
4. brain stem

Question 6

describe the cerebrum

Answer 6

the majority of the brain (big wavy bits), divided into left and right hemispheres, contains the cerebral cortex an cerebral medulla

Question 7

what is the cerebral cortex?

Answer 7

the outer portion of the cerebrum (gray matter)

Question 8

what is the cerebral medulla?

Answer 8

the inner portion of the cerebrum (white matter)

Question 9

where is the cerebellum located?

Answer 9

caudal and ventral to cerebral hemispheres

Question 10

list the 3 components of the interbrain

Answer 10

1. hypothalamus
2. thalamus
3. epithalamus

Question 11

what gland is attached to the hypothalamus and what does it do?

Answer 11

the pituitary gland, involved in regulating hormone release

Question 12

what is the function of the thalamus?

Answer 12

to relay signals to the rest of the brain

Question 13

what gland is located in the epithalamus and what does it secrete?

Answer 13

the pineal gland, secretes melatonin

Question 14

list and describe the locations of the 3 components of the brain stem

Answer 14

1. midbrain: top of stem
2. pons: ventral to midbrain
3. medulla oblongata: ventral to pons, attaches to spinal cord

Question 15

what is the function of the blood-brain barrier?

Answer 15

regulate movement of materials from the blood into the brain

Question 16

can most drugs easily cross the blood-brain barrier?

Answer 16

no they must be designed specifically

Question 17

describe the structure of the blood-brain barrier

Answer 17

astrocytes surround capillaries in the brain and push simple squamous cells (endothelial cells lining those capillaries) closer together to form tight junctions between the cells, meaning that anything entering the brain from the blood must now travel through the endothelial cells instead of around them, requiring transport receptors thus providing more protection

Question 18

can glucose pass through the blood-brain barrier? why or why not?

Answer 18

it can because it’s small

Question 19

what does the blood-brain barrier mean for infections of the nervous system like rabies or tetanus?

Answer 19

they are much harder to treat

Question 20

where is the spinal cord found and what makes up its structure?

Answer 20

within white matter, made of different tracts of axons

Question 21

list and describe the 2 kinds of fibers in the spinal cord

Answer 21

1. afferent fibers: relay sensory information from periphery to the brain (AKA sensory fibers)
2. efferent fibers: relay motor information from brain to periphery (also called motor fibers)

Question 22

what do Efferent fibers do?

Answer 22

cause an Effect in the body

Question 23

what is the cauda equina?

Answer 23

the terminal end of the spinal cord, which gets smaller going down its length and resembles a horse’s tail

Question 24

what are and how many meninges are there?

Answer 24

protective membranes, 3 layers of connective tissue

Question 25

what is the most superficial layer of the meninges?

Answer 25

the dura mater

Question 26

what is the dura mater made of and what is it attached to?

Answer 26

dense irregular connective tissue (the most protective layer), attached directly to the skull

Question 27

what is the space between the dura mater around the spinal cord and vetebrae called and what is it used for?

Answer 27

the epidural space, where we inject drugs

Question 28

describe the arachnoid layer of the meninges

Answer 28

thin, wispy, fibrous layer, looks like a spider web, NONVASCULAR

Question 29

what is the deepest layer of the meninges?

Answer 29

the pia mater

Question 30

describe the pia mater

Answer 30

bound tightly to the brain and spinal cord, thin, fibrous, also nonvascular

Question 31

what is the space between the pia mater and the arachnoid space called?

Answer 31

the aubarachnoid space

Question 32

where is cerebrospinal fluid located?

Answer 32

in the subarachnoid space

Question 33

what is the function of cerebrospinal fluid?

Answer 33

acts as a protective cushion produced by ependymal cells

Question 34

what are the 2 components of the peripheral nervous system?

Answer 34

1. spinal nerves | 2. cranial nerves

Question 35

name one type of spinal nerve and its function and location

Answer 35

somatic nerves; associated with voluntary control of movement; found in pairs off each side of each vertebra (1L and 1R)

Question 36

what do dorsal roots do?

Answer 36

carry afferent impulses to spinal cord

Question 37

name the location and function of the dorsal root ganglion

Answer 37

sits at the base of the dorsal root and receives afferent signals from periphery; sends to CNS

Question 38

what do ventral roots do?

Answer 38

carry efferent (reactionary) signals (impulses) to periphery

Question 39

describe a mixed nerve

Answer 39

contains both motor (efferent) and sensory (afferent) axons, both to and away from periphery

Question 40

where are the cranial nerves located?

Answer 40

innervating the face and neck

Question 41

how many pairs and what type of nerves are cranial nerves?

Answer 41

12 pairs, afferent. efferent, and mixed

Question 42

does the autonomic nervous system require conscious perception?

Answer 42

no!

Question 43

list the 3 parts of the autonomic nervous system

Answer 43

1. sympathetic nervous system 2. parasympathetic NS 3. enteric NS

Question 44

describe the sympathetic nervous system

Answer 44

associated with the body's responses to stress

Question 45

describe the parasympathetic nervous system

Answer 45

associated with the body's responses to nonstress, during the absence of stress

Question 46

describe the enteric nervous system

Answer 46

has components of both sympathetic and parasympathetic NS, controls digestive system under stress and nonstress

Question 47

define potential

Answer 47

a relative electrical charge between 2 points

Question 48

membrane potential

Answer 48

relative electrical charge between the inside and outside of a cell membrane

Question 49

what causes a membrane potential?

Answer 49

differences in concentrations of ions across a cell membrane

Question 50

define resting membrane potential

Answer 50

differences in ion concentrations across the cell membrane when the cell is at rest

Question 51

describe the general resting membrane potential

Answer 51

slightly more positive charge on the outside of the membrane than on the inside

Question 52

what do Na+-K+ ATPases do?

Answer 52

transport 3 Na+ outside cell for every 2 K+ that enter

Question 53

describe the contribution of channels in neurons and other cells

Answer 53

Na+ channels transport Na+ into the cell and K+ channels transport K+ out of the cell; both move along a concentration gradient and are both closed at rest, with no contribution to the membrane potential at rest

Question 54

name and describe the 1 state of the transmission of a nerve impulse

Answer 54

resting state: cell membrane is at resting potential with slightly more positive charge outside than inside

Question 55

name and describe the 2nd state of the transmission of a nerve impulse

Answer 55

chemical stimulation of membrane: signals for start of impulse transmission, something binds to receptor neuron to start

Question 56

name and describe the 3rd state of the transmission of a nerve impulse

Answer 56

depolarization: will occur at the site on the membrane that was stimulated, only at one specific place Na+ channels OPEN, Na+ enters the cell (K+) channels still closed membrane potential now more positive on inside of cell

Question 57

name and describe the 4th state of the transmission of a nerve impulse

Answer 57

repolarization begins: Na+ channels CLOSE, Na+ stops entering cell, K+ channels open at same time, and K+ leaves the cell Na+ starts moving away from the site of stimulation

Question 58

name and describe the 5th state of the transmission of a nerve impulse

Answer 58

repolarization continues until: membrane returns to resting potential, which must happen in order for next impulse to occur Na+-K+ ATPase helps to reestablish Na+ on outside of cell and K+ on inside of cell

Question 59

where do steps 1-5 of transmission of a nerve impulse occur?

Answer 59

all on one spot on the cell membrane

Question 60

name and describe the 6th state of the transmission of a nerve impulse

Answer 60

propagation of an action potential: changes in membrane potential travel down length of the membrane Na+ moving away from site of depolarization results in depolarization at next spot on membrane

Question 61

name and describe the 7th state of the transmission of a nerve impulse

Answer 61

action potential continues: to terminal end of axon

Question 62

name and describe the 8th state of the transmission of a nerve impulse

Answer 62

action potential traveling results in the release of a neurotransmitter: into synapse

Question 63

define saltatory conduction

Answer 63

transmission of a nerve impulse down a myelinated axon, action potential "jumps" from one node of Ranvier to the next

Question 64

what does saltatory conduction do to the transmission of a nerve impulse?

Answer 64

speeds it up, increases rate of nerve impulse signalling

Question 65

define neurotransmitters

Answer 65

chemical substances (messengers) released by an axon into synapses, transmit the nerve impulses from one neuron to the next