2.6/2.7 Intro to Nervous system

Question 1

_____ are the functional unit of the NS that are specialized to receive stimuli and generate/conduct electrical impulses (action potentials)

Answer 1

neurons

Question 2

What are glia?

Answer 2

• supporting cells in nervous system

Question 3

what do glial cells do?

Answer 3

1. make myelin
2. protection
3. metabolic exchange with the vascular system

Question 4

what are the functional components of neurons?

Answer 4

• cell body/soma
• nucleus (large/central) (euchromatic)
• prominent nucleolus
• several organelles
• axons and dendrites

Question 5

nucleus stains _____ in neuroglial cells

Answer 5

heterochromatic (stain uniformly and intensely)

Question 6

What are Nissl bodies?

Answer 6

rough ER in a neuron

Question 7

neurons can have _____ dendrites but must have _____ axon

Answer 7

multiple

ONLY one

Question 8

Dendrite physical characteristics

Answer 8

• extension of soma, they have organelles
• they taper (get skinnier as you move away from soma)
• have dendritic spines
• have NO golgi

Question 9

what do dendrites do?

Answer 9

receive info

Question 10

can dendrites be myelinated?

Answer 10

NO only axons can

Question 11

axon physical characteristics

Answer 11

• only one per neuron
• axon hillock
• axon collaterals

Question 12

does an axon have NIssl bodies?

Answer 12

NO

Question 13

what is the axon hillock?

Answer 13

where AP is generated

Question 14

what are axon collaterals? what can they cause?

Answer 14

• when the axon splits/branches

- can cause referred pain

Question 15

do axons have myelin?

Answer 15

they can! not alll do though

Question 16

what is dull pain coming from?

Answer 16

unmyelinated axon

Question 17

what is anterograde axon transport?

Answer 17

going forward

Question 18

retrograde transport

Answer 18

moving backwards

Question 19

_____ transport proteins in an axon

Answer 19

microtubules (kinesin and dyenin)

Question 20

what is CNS made up of?

Answer 20

brain/spine

Question 21

what is PNS made up of? (3)

Answer 21

1. cranial nerves
2. spinal nerves
3. ganglion

Question 22

what are the types of ganglion? (4)

Answer 22

astrocytes
microglia
oligodendrocytes
ependymal

Question 23

astrocytes

Answer 23

monitor blood brain barrier

Question 24

microglia

Answer 24

eat debris

Question 25

oligodendrocytes

Answer 25

make myelin

Question 26

ependymal

Answer 26

have cilia, beat and circulate cerebrospinal fluid

Question 27

node of ranvier

Answer 27

space inbetween myelin sheaths

Question 28

how can you classify neurons? (3)

Answer 28

1. # of cell processes (uni, pseudouni, bi, multi) 2. morphology of dendrites 3. function

Question 29

what are the 3 types of neurons?

Answer 29

1. motor 2. sensory 3. interneurons

Question 30

what are unipolar neurons and what do they do?

Answer 30

- not committed to final form, no dendrite | - embryogenesis

Question 31

what are Bipolar neurons and what do they do?

Answer 31

- 1 dendrite, 1 axon - conduct info for special senses (olfactory, cochlear, etc) * *only 4 special senses- eye, ear, mouth, nose**

Question 32

what are pseudo-unipolar neurons and what do they do?

Answer 32

- 1 axon comes off and splits into 2 | - sensory neurons

Question 33

what are multipolar neurons and what do they do?

Answer 33

- many dendrites and 1 axon | - motor neurons, pyramidal cells, purkinje cells

Question 34

neurons are specialized to do what 3 things?

Answer 34

1. receive (dendrites) 2. integrate (axon hillock) 3. transmit electrochemical signals (axon)

Question 35

synapse

Answer 35

specialized jxn which signals are transmitted from a neuron to its target cells -UNIdirectional

Question 36

is there a space between a pre- and post-synaptic cell in the synapse?

Answer 36

YES

Question 37

synaptic cleft is around ____ wide

Answer 37

20nm

Question 38

Schwann cells

Answer 38

- makes myelin in PNS -also can provide support -located at axon (same as oligodendrocyte)

Question 39

satellite cells

Answer 39

glial cell in periphery that provide support to CELL BODY in sensory ganglia

Question 40

what are the different sheaths of peripheral nerves from outside in?

Answer 40

epinourium, perineurium, endoneurium

Question 41

which sheath is the closest to the axon?

Answer 41

endoneurium

Question 42

you can have neural regeneration in the _____ but not in the _____.

Answer 42

PNS, CNS

Question 43

why cant CNS neurons regenerate?

Answer 43

they cant reconnect bc helper cells infiltrate the area and build a wedge between the neurons

Question 44

how can a neuron regenerate?

Answer 44

- dispersal of nissl bodies and weird placement of nucleus - macrophage eats dead stuff - schwann cells proliferate and build back up

Question 45

can you get a connection back if the schwann cells stop proliferating?

Answer 45

NO

Question 46

chromatolysis

Answer 46

-dispersion of nissl bodies and eccentric position of nucleus