Exam Iii

Front 1

transmembrane potential (TMP)

Back 1

difference in voltage between inside and outside of cell

Front 2

resting membrane potential (RMP)

Back 2

when the cell is not electrically active

Front 3

graded potential

Back 3

any charge that brings a cell out of rest

Front 4

action potential

Back 4

generated when graded potential reaches threshold

Front 5

depolarization

Back 5

making the membrane more positive

Front 6

repolarization

Back 6

returns membrane to resting potential

Front 7

hyperpolarization

Back 7

results when potassium ions move out, inside of cell becomes more negative, , making the charge differential

Front 8

threshold for axon

Back 8

depolarization of 10-15 mV

Front 9

all or nothing

Back 9

You send an impulse via nerve to the motor endplate, where the neurons meets up with the skeletal muscle fiber. If this excitation (via release of ACh) is enough to cross the threshold in the postsynaptic cell (the motor fiber). If this stimuli is strong enough, it will cause a depolarization of the muscle, which causes the sarcoplasmic reticulum to release calcium and cause a series of reactions within the muscle to make it contract. Thusly, if a muscle fiber is activated with a strong enough impulse, it will contract. This contraction is the same strength regardless of the intensity of the neuronal signaling (after it has crossed the threshold for excitation), so the fiber contracts. Your muscle fibers only have one strength, on or off. To vary your lifting, say a heavy object versus a lighter one, you recruit fewer muscle fiber bundles, rather than have all of the muscle fibers contract at a lesser intensity. they can't contract at a lesser intensity, so it is said to be all or none.

Front 10

afferent division is divided into what two divisions

Back 10

somatic and visceral sensory

Front 11

efferent division is divided into what two divisions

Back 11

somatic nervous system and autonomic nervous system

Front 12

multipolar neuron services what organ

Back 12

brain

Front 13

bipolar neuron services what organs

Back 13

sensory organs

Front 14

unipolar services what parts of the body

Back 14

sensory neurons of the PNS

Front 15

name three nueron functions

Back 15

sensory nueron, internueron, motor neuron

Front 16

function of sensory neuron

Back 16

carries information from receptor to CNS

Front 17

internueron function (association nueron)

Back 17

link between sensory and organ neurons

Front 18

motor nueron function

Back 18

carries information from brain to effectors

Front 19

passive (leak) channel

Back 19

permanently open

Front 20

three types of active channels and how they're activivated

Back 20

mechanical- activitated by pressure/vibration
ligand/chemical- activated by neurons
voltage- activated by charge

Front 21

name 3 states of gated channels

Back 21

1) closed but can be opened by stimulus
2) open, activated
3) closed, cannot be activated

Front 22

four types of glial cells in the CNS

Back 22

astrocytes, ependymal, oligodentrocytes, microglia

Front 23

astrocytes

Back 23

maintains blood brain barrior

Front 24

ependymal cells

Back 24

produce CSF

Front 25

oligodentrocytes

Back 25

myelinate axons

Front 26

microglia

Back 26

fight infections

Front 27

2 types of glial cells in peripheal nervous system

Back 27

satellite cells and schwann cells

Front 28

satellite cells

Back 28

regulates O2, CO2, nutrient and nuerotransmitter levels around neurons

Front 29

schwann

Back 29

provides myelination to axons

Front 30

threshold for axon

Back 30

depolarization of 10-15 mV

Front 31

5 stages of generation of action potential

Back 31

1) depolarization to threshold
2) activation of Na+ gated channels and rapid depolarization
3) inactivation of Na- channels and activation of K+ channels
4) return to normal permeability
5) refractory period

Front 32

where is action potential propagated

Back 32

axon

Front 33

where are potentials passed onto the next cell

Back 33

synaptic terminals

Front 34

relative refractory period

Back 34

initiation of a second action potential is inhibited but not impossible

Front 35

refractory period

Back 35

the amount of time it takes for an excitable membrane to be ready for a second stimulus once it returns to its resting state following an excitation

Front 36

absolute refractory period

Back 36

cannot execute muscle contraction at all

Front 37

continuous propagation of impulse (action potential)

Back 37

local currents depolarize adjacent areas of membrane so that action potentials continue to form along the membrane

Front 38

saltatory propagation of impulse

Back 38

propagation of action potentials along myelinated axons from one node of Ranvier to the next node, increasing the conduction velocity of action potentials without needing to increase the diameter of an axon.

Front 39

where is action potential generated

Back 39

axon hillock

Front 40

this part of the skeletal muscle cell releases calcium when stimulated by the T tubultes

Back 40

terminal cisterns of sarcoplasmic reticulum

Front 41

what type of synapse dominates the nervous system?

Back 41

chemical

Front 42

band of connective tissue that surrounds muscles

Back 42

epimysium

Front 43

graded potentials can involve either depolarization or hyperpolarization, true or false

Back 43

T

Front 44

two types of synapses

Back 44

electrical and chemical

Front 45

electrical synapse

Back 45

no gap between the presyn. and post-synaptic cells, the 2 cells are joined by connexons

Front 46

2 types of post-synaptic potentials

Back 46

excitatory post-synaptic potential and inhibitory

Front 47

excitatory post-synaptic potential

Back 47

graded depolarization caused by arrival of neurotransmitter at the postsyn. membrane- results from openings of chemically gates membrane channels that lead to depolarization

Front 48

inhibitory post-synaptic potential

Back 48

graded hyperpolarization- its inhibited because while hyperpolarization continues, the nueron is inhibited and requireds a larger than usual depolarizing stimulus

Front 49

2 kinds of summation

Back 49

spatial and temporarl

Front 50

spatial summation

Back 50

potentials arrive at different locations at the same time

Front 51

temporal summation

Back 51

potentials arrive at ONE location in rapid succession

Front 52

in electrical synapses, 2-way transmission of impulses is possible, T or F

Back 52

T

Front 53

where can electrical synapses be found?

Back 53

the brain, including the vestibular nuclei, the eye, and in one pair of PNS ganglia (ciliary ganglia)

Front 54

function of neurotransmitters

Back 54

to open or close ion channels that influence membrane that influence membrane permeability

Front 55

hierarchical arrangement of skeletal muscle

Back 55

Z-line
z-line sandwiching H-zone
A and I bands
sarcomers
myofibrils
muscle fibers
fascicles
skeletal muscle

Front 56

each muscle fiber is surrounded by

Back 56

sarcolemma

Front 57

myofibrils have how many sarcomers

Back 57

10,000

Front 58

muscle fibers are made up of

Back 58

myofibrials

Front 59

what role does the elastic prtein titin have in muscle contraction

Back 59

pulls thin filament towards the M-line in the A band, the I--band (area between successive A-bands) shorten, but the A band remains the same. contraction stops when the Z-line touches the ends of teh thick filaments, at which point the I-band disapears

Front 60

sarcome is the area between

Back 60

2 successive z-lines

Front 61

a sarcomere has how many myofilaments

Back 61

2, the thick and thin

Front 62

thin filament has what proteins

Back 62

actin, nebulin, troponin, tropomyosin

Front 63

M line

Back 63

situated in middle and divides the sarcomere into equal halves

Front 64

thick filaments are attached to the

Back 64

M-line

Front 65

thin filaments are attached to the

Back 65

z-lines

Front 66

titin connects:

Back 66

head of the thick to teh z-line which creates 3 zones where the major myofilaments can be found

Front 67

A-band

Back 67

runs entire lenght of the thick filamanet on either side of the M-line- has a part where thick and thin overlap

Front 68

what role does troponin have in muscle contraction

Back 68

arriving AP stimulates sarcoplasmic reticulum into relasing Ca2+ into sarcoplasm, the extra Ca2+ binds to troponin

Front 69

a cross-bridge is formed when

Back 69

a myosin head binds to an active site on the thin filament (f-actin)

Front 70

twitch

Back 70

single stimuls-contraction-relaxation sequence in a muscle fiber

Front 71

twitch can be divided into

Back 71

latent period
contraction phase
relaxation phase

Front 72

treppe

Back 72

if a skeletal muscle is stimulated a 2nd time immediately after relaxation phase, the contraction will develop a slightly higher maximum tension than at the first stimulus. amount of tension produced remains constant, Because the tension rises in stages, its called treppe