Nervous System

Question 1

central nervous system

Answer 1

brain and spinal cord

Question 2

peripheral nervous system

Answer 2

nerves of the body

Question 3

somatic nervous system

Answer 3

controls voluntary actions

Question 4

autonomic nervous system

Answer 4

controls involuntary actions

Question 5

sympathetic nervous system

Answer 5

fight or flight response (part of autonomic)

Question 6

parasympathetic

Answer 6

calms down body after fight or flight (part of autonomic)

Question 7

astrocytes

Answer 7

▫bring a neuron nutrients and take away waste

▫connect capillaries and neurons

Question 8

microglia

Answer 8

carry out phagocytosis on neurons and microorganisms

Question 9

what forms the blood-brain barrier

Answer 9

asteocytes

Question 10

ependymal cells

Answer 10

produce cerebrospinal fluid

Question 11

oligodendrocytes

Answer 11

produce myelin sheaths around axons

Question 12

schwann cells

Answer 12

▫wrap itself around the axon to create myelin sheath

▫found only in peripheral nervous system

Question 13

satellite cell

Answer 13

supports cell bodies of neurons in ganglia

Question 14

steps of action potential

Answer 14

1. stimulus
2. depolarization
3. repolarization
4. hyperpolarization
5. returning to rest

Question 15

step 1: stimulus

Answer 15

stimulus excites neuron and opens some mechanically gated sodium channels. may or may not cause action potential

Question 16

what is the cells resting voltage

Answer 16

-70mV

Question 17

cell’s threshold

Answer 17

-55mV

Question 18

step 2: depolarization

Answer 18

of threshold is reached, voltage gated sodium channels open and sodium ions enter, depolarizing the axon

Question 19

step 3: repolarization

Answer 19

when membrane is depolarized to 30mV voltage gated potassium channels open. reestablishes membrane potential

Question 20

step 4: hyperpolarization

Answer 20

too much potassium flows out and axon becomes slightly more negative

Question 21

step 5: returning to rest

Answer 21

sodium potassium pump reestablishes original gradient and returns axon to resting potential

Question 22

propagation

Answer 22

movement of an action potential down an axon

Question 23

refractory period

Answer 23

the period during an action potential when an axon cannot respond to any other stimuli

Question 24

absolute refractory

Answer 24

when sodium channels are already open (can’t open more)

Question 25

relative refractory period

Answer 25

during hyperpolarization, when sodium channels are normal, requires larger stimulus to reach action potential

Question 26

layers of a nerve, including membranes

Answer 26

``` neuron (nerve fiber) endoneurium fascicle perineurium nerve epinerium ```

Question 27

endoneurium

Answer 27

around each individual neuron

Question 28

perineurium

Answer 28

around each fascicle

Question 29

epineurium

Answer 29

around entire nerve

Question 30

electrical synapse

Answer 30

▫direct contact between neurons via gap junctions | ▫impulse travels directly from one neuron to the next

Question 31

chemical synapse

Answer 31

▫separated by synaptic cleft | ▫electrical impulse turned into chemical signal via neurotransmitter release

Question 32

excitatory chemical signal

Answer 32

cause depolarization, promote new action potential

Question 33

inhibitory chemical signal

Answer 33

cause hyperpolarization, suppresses new action potentials

Question 34

cholinergic synapses

Answer 34

release acytlecholine

Question 35

steps of acetylcholine release

Answer 35

▫impulse reaches terminal bulb ▫calcium enters terminal bulb ▫ACh is released from vesicles via exocytosis ▫ACh binds to receptors to cause depolarization in next neuron ▫ACh is broken down by AChE into acetate and choline ▫choline pumped back into terminal bulb to create more ACh

Question 36

synaptic delay

Answer 36

braid period of delay between conversion of electrical signal to chemical signal and back

Question 37

synaptic fatigue

Answer 37

running out of neurotransmitter

Question 38

direct effect

Answer 38

neurotransmitter releases and binds with receptors, this causes opening of ligand gated channels

Question 39

indirect effect via g protein

Answer 39

neurotransmitter binds and causes activation of a g protein, this causes opening of ion channels

Question 40

indirect effect via enzymes

Answer 40

neurotransmitters diffuse across membrane and activate enzymes with produce other compounds which open ion channels

Question 41

axoaxonic synapses

Answer 41

axon connects to the axon terminal of another neuron

Question 42

neurolemma

Answer 42

part of schwann cell where cytoplasm gets squeezed to the perimeter

Question 43

afferent

Answer 43

carry info to the CNS

Question 44

efferent

Answer 44

carry info from the CNS

Question 45

functions of the nervous system

Answer 45

▫gathers info ▫info is integrated (brought together) ▫responds to signals ▫maintains homeostasis

Question 46

number of cranial nerves

Answer 46

12 pairs

Question 47

number of spinal nerves

Answer 47

31 pairs

Question 48

interneurons

Answer 48

connect sensory neurons with motor neurons and brain and spinal cord

Question 49

afferent and efferent are part of the ______ nervous system

Answer 49

peripheral

Question 50

are large or small diameter neurons faster

Answer 50

large