organization of the nervous system

Question 1

3 subdivisions of the nervous system

Answer 1

• central
• peripheral
• autonomic

Question 2

2 parts of CNS

Answer 2

• brain

- spinal cord

Question 3

3 meninges of CNS

Answer 3

• dura mater (outer membrane)
• arachnoid (middle membrane)
• pia mater (inner membrane)

Question 4

nuclei

Answer 4

aggregations of neurons that share similar functions

Question 5

gray matter

Answer 5

contains neuron cell bodies

Question 6

white matter

Answer 6

rich in myelin

Question 7

peripheral nervous system (PNS)

Answer 7

those parts of the nervous system that lie outside the dura mater

Question 8

afferent nerves

Answer 8

sensory nerves that carry messages from the periphery to the CNS

Question 9

efferent nerves

Answer 9

peripheral motor nerves that carry messages from the CNS to peripheral tissues

Question 10

peripheral ganglia

Answer 10

groups of nerve cells concentrated into small knots or clumps that are located outside the CNS

Question 11

autonomic nervous system (ANS)

Answer 11

portion of the nervous system that regulates and controls visceral functions

Question 12

2 parts of nervous tissue

Answer 12

• neurons

- neuroglial cells (glia)

Question 13

purpose of neurons

Answer 13

electrical communication

Question 14

what did the neuron doctrine say

Answer 14

neurons are entirely separate from one another, even though their processes come into very close contact

Question 15

4 domains of structure of a neuron

Answer 15

• cell body (soma, perikaryon)
• dendrites
• axon
• presynaptic terminals

Question 16

3 fibrillary structures of the cytoskeleton

Answer 16

• neurofilaments
• microtubules
• thin filaments

Question 17

cell body

Answer 17

the portion of the cell surrounding the nucleus

Question 18

function of dendrites

Answer 18

receiving information
(their membranes are endowed with receptors that bind and respond to the neurotransmitters released by neighbouring cells)

Question 19

axon hillock

Answer 19

point of origin of axon

Question 20

initial segment (spike initiation zone)

Answer 20

distal to hillock, untapered, unmyelinated region

Question 21

axoplasm

Answer 21

cytoplasm of the axon, packed with parallel arrays of microtubules and neurofilaments

Question 22

function of axons

Answer 22

message-sending

Question 23

myelin

Answer 23

coiled cell membranes of glial cells

Question 24

continuous propagation

Answer 24

way of traveling of action potential if axon is not covered with myelin

Question 25

saltatory conduction

Answer 25

way of traveling of action potential if axon is myelinated

Question 26

node of Ranvier

Answer 26

space between adjacent myelin segments

Question 27

function of presynaptic terminals

Answer 27

rapid conversion of the neuron's electrical signal into a chemical signal

Question 28

synaptic transmission

Answer 28

release of chemical signaling molecules when the action potential reaches the presynaptic terminal

Question 29

chemical synapse

Answer 29

junction formed between the presynaptic terminal and its target

Question 30

3 parts of synapse

Answer 30

- presynaptic terminal - postsynaptic membrane - synaptic cleft

Question 31

dendritic spine

Answer 31

small membranous protrusion from a neuron's dendrite

Question 32

what's MAPs the abbreviation for?

Answer 32

microtubule-associated proteins

Question 33

2 major classes of MAPs

Answer 33

- high-molecular-weight protein (MAP-1, MAP-2) | - lower-molecular-weight tau proteins

Question 34

neurofibrilarry tangles

Answer 34

abnormal accumulations of a protein called tau that collect inside neurons caused by hyperphosphorylated tau proteins

Question 35

orientation of microtubules in axons

Answer 35

with plus ends pointed away from the cell body

Question 36

anterograde direction

Answer 36

mechanism for moving material to the presynaptic terminals | to + end

Question 37

retrogade direction

Answer 37

moving material from the presynaptic terminals | to - end

Question 38

3 ways of axoplasmic transport

Answer 38

- fast anterograde - fast retrograde - slow anterograde

Question 39

direction in which kinesin moves

Answer 39

toward the plus end of microtubules (away from the cell body)

Question 40

how does anterograde movement work

Answer 40

- proteins synthesized in the 'secretory pathway' are packaged by budding off in the membrane-enclosed vesicles from the Golgi - the vesicles and mitochondria are carried down the axon on microtubule 'tracks' by kinesin motors that are energized by ATP

Question 41

synonym for MAP-1C (used in retrograde movement)

Answer 41

brain dynein

Question 42

kinesin

Answer 42

microtubule-dependent motor protein (used in anterograde movement)

Question 43

consequence of loss of ATP production in axons

Answer 43

failure of axonal transport in both the anterograde and retrograde directions

Question 44

2 types of neurons based on axonal projection

Answer 44

- projection neuron (principal neurons, golgi type I cells) (connect with other parts of the nervous system) - interneurons (intrinsic neurons, golgi type II cells) (all processes confined to one region of the brain)

Question 45

2 types of neuron based on dendritic geometry

Answer 45

- pyramidal cells (spiny) | - stellate cells (spiny or aspiny)

Question 46

3 types of neurons based on number of processes

Answer 46

- unipolar (dorsal root ganglion cell) - bipolar (retinal bipolar cell) - multipolar

Question 47

what 3 elements do glial cells lack

Answer 47

- axons - action potentials - synaptic potentials

Question 48

3 main types of CNS glial cells

Answer 48

- oligodendrocytes - astrocytes - microglial cells

Question 49

3 main types of glial cells in PNS

Answer 49

- satellite cells - Schwann cells - enteric glial cells

Question 50

what do oligodendrocytes form

Answer 50

the myelin sheaths of CNS axons

Question 51

function of Schwann cells

Answer 51

to myelinate peripheral nerves

Question 52

2 types of neurons based on direction

Answer 52

- afferent (sensory) | - efferent (motor)

Question 53

2 types of neurons based on the anatomical distribution of the information flow

Answer 53

- visceral | - somatic

Question 54

2 types of neurons based on the information flow on the basis of the embryological origin of the structure being innervated

Answer 54

- special (for example: from the branchial arch region of the embryo) - general