Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Physiology 210 > Nerve, Muscle, Synapse Physiology > Flashcards

Nerve, Muscle, Synapse Physiology Flashcards

1
Q

3 types of neurons

A

Afferent neurons - take info from periphery to CNS, contact efferent of interneurons, excitatory, PNS
Efferent neurons - take info from CNS to periphery, contact onto muscle, excitatory, PNS
Interneurons - carry info between neurons, contatct efferent or interneurons, excitatory or inhibitory, CNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Glia

A
  • glue of nervous system
  • numerous and small
  • Oligodendrocytes - myelin in CNS
  • Schwann cells - myelin in PNS
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Gray matter

A

in spinal cord
horn/butterfly shape
unmyelinated axons and interneurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

White matter

A

in spinal cord
surrounds horn/butterfly shape
myelinated axons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Afferent neurons use the _____ route

A

dorsal - back

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Efferent neurons use the _____ route

A

ventral - front

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Myelin

A

lipid protein mix
wrapped around axon (ensheathing)
acts as an insulator and does not allow ions to move across axon where myelin is present
quickens the speed of electronic conduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Dendrites

A

receive information from periphery or other cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Cell body

A

contains nucleus, also called soma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Axon hillock

A

Initial segment of axon, processes info coming from dendrites and generates nerve impulse if reaches threshold

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Axon

A

propagates nerve impulse from axon hillock to axon terminal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Axon terminal/synaptic terminal

A

contains neurotransmitter in synaptic vesicles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Synapse

A

junction between 2 neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Presynaptic neuron

A

the neuron before the synapse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Postsynaptic neuron

A

the neuron after the synapse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Membrane of neuron

A

Phospholipid bilayer
Contains protein pumps - active transport
Contains ion channels - passive transport: passive channels, ligand-gated channels, voltage-gated channels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Resting membrane potential

A
  • charge separation between inside and outside of cell at steady state
  • around -70 mV
  • important ions are Na+ and K+
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Na+/K+ pump

A

3 Na+ pumped out of cell
2 K+ pumped into cell
Net +1 out of cell for each cycle
Net negative change inside cell
Uses ATP
Creates Na+ and K+ gradients

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Leak K+ channels

A

Chemical force pushes K+ out of cell
Electrical force pushes K+ into cell
Equilibrium potential: -90 mV
K+ will move out of cell
More leak channels for K+ - greater membrane permeability

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Leak Na+ channels

A

Chemical force pushed Na+ into cell
Electrical force pushed Na+ into cell
Equilibrium potential: +55 mV
Na+ will move into cell
Less leak channels for Na+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q
  1. Stimuli
A

disrupts steady state by causing ion selective channels in membrane to open
increased opening of Na+ receptors and entry of Na+ into afferent neuron
DEPOLARIZATION to reach threshold

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q
  1. Threshold
A

around -50 mV
if neuron reaches this level then action potential is generated
voltage-gated Na+ channels open, activation gate is removed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q
  1. Action potential
A

electrical signals generated by activity of Na+ rushing in by voltage gated Na+ channels
-70 mV to +30 mV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q
  1. Repolarization
A

inactivation gate closes Na+ voltage channel
activation gate opens K+ channel and K+ leaves cell and takes positive charge with it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q
  1. Refractory period
A

Absolute refractory period - another action potential cannot be generated in response to stimulus due to inactivation of voltage-gated Na+ channels
Relative refractory period - another action potential will only be generated if stimulus is greater strength then usual threshold

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Conductance

A

rate of ion travel through a channel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Action potentials: transmission

A

local depolarization of membrane causes adjacent voltage-gated Na+ channels to activate
new action potential is generated in adjacent membrane
transmitted from segment to segment along the axon
travels one direction due to refractory period

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Electronic conduction

A

spread of current inside axon due to depolarization of segment to segments
proceeds in one direction
at node of Ranvier

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Nodes of Ranvier

A

on a myelinated axon, it is an unmyelinated region
contain voltage gates Na+ channels
electronic conduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Nodes of Ranvier PNS

A

single Schwan cell myelinates one segment of axon

31
Q

Nodes of Ranvier CNS

A

single oligodendrocyte myelinates several axons and several regions of given axon

32
Q

Saltatory conudction

A

propagation of action potential along myelinated axon such that action potentials jump from one node of Ranvier to another node
action potential can pass undiminished in size from each node

33
Q

2 factors which determine speed or propagation

A

Size of the axon: the thicker the faster
Myelination: faster than unmyelinated

34
Q

Synaptic transmission

A

one neuron communicates with other neuron or effecter at a synapse
action potential at presynaptic terminal depolarizes and opens voltage gated calcium channels to open
calcium causes vesicles containing neutrotransmitters to move to and fuse with membrane

35
Q

Electrical synapse

A

physical connection between 2 very close cells
passage of ions and small molecules
connexin: protein channel
flows both ways
open or closed
fast communication
always excitatory

36
Q

Chemical synapse

A

presynaptic and postsynaptic cell with no physical connection - definitive gap called synaptic cleft
one direction only
directly gated: receptor and ion channel are same protein, fast short lasting
indirectly gated: receptor and ion channel are different protein, slow long lasting

37
Q

Neurotransmitter

A

stores in presynaptic terminal in synaptic vesicle
released from vesicle into synaptic gap and binds to receptors of postsynaptic cell and ligand gated ion channels
causes opening of ion channels on postsynaptic cell to either depolarize or hyperpolarize
either inhibitory or excitatory not both

38
Q

Excitatory neutrotransmitter

A

glutamate released by excitatory neurons
will open a Na+ channel when bound, Na+ into cell
depolarization
excitatory post synaptic potential is generated (EPSP)

39
Q

Inhibitory neutrotransmitter

A

glycine or GABA released by inhibitory neurons
will open a Cl- or K+ channel, Cl- into cell, K+ out of cell
hyperpolarization
inhibitory post synaptic potential is generated (IPSP)

40
Q

Chemical synapses - indirectly gated

A

Neurotransmitter binds to receptor and activates 2nd messenger system
G protein - GTP activates adenylyl cyclase which converts ATP into cAMP - second messenger
cAMP activates protein kinases which phosphorylates a channel and causes it to open or close

41
Q

Synaptic potential and integration

A

synaptic potentials decay as they travel away from the synapse
can only travel short distances INTEGRATION
axon hillock constantly calculates total amount of excitation and inhibition

42
Q

Post synaptic potentials

A

generate enough depolarizations to bring to threshold and produce action potential by summation as they are only 0.2 mV by themselves

43
Q

2 types of summation

A

Temporal: multiple PSPs from single presynaptic neuron arrive at cell body at same time
Spatial: multiple PSPs from different presynaptic neurons arrive at cell body at same time
Can receive EPSP and IPSP at same time and net voltage will occur

44
Q

Complexity of behaviour

A

the exact same stimulus in two different situations can generate two completely different responses
because of an increase or decrease of inhibition or excitation of different neurons within a pathway

45
Q

AP vs PSP: amplitude

A

AP: same size, depolarizing, all or nothing
PSP: small, depolarizing or hyperpolarizing

46
Q

AP vs PSP: duration

A

AP: short duration (2-3 ms)
PSP: long duration (10-20 ms)

47
Q

AP vs PSP: location

A

AP: initiated at axon hillock and transmitted down the axon to synaptic terminal
PSP: initiated at dendrites or soma as this is where synapse is location

48
Q

AP vs PSP: conduction

A

AP: active, long distance, regenerate at each point
PSP: passive, short distance, decrease in amplitude

49
Q

AP vs PSP: function

A

AP: generated if threshold is reached ad will travel to synaptic terminal to initiate neurotransmitter release
PSP: change electrical potential of post synaptic neuron, either depolarizing or hyperpolarizing based on neurotransmitter
PSP will trigger AP when axon hillock is depolarized to threshold

50
Q

Skeletal muscle

A

muscle attached to skeleton, striated muscle, contraction is under voluntary control

51
Q

Endomysium

A

membrane that sits over each muscle cell and electrically isolates the muscles cells from each other

52
Q

Motor unit

A

the motor neuron (efferent neuron), its axon and all muscle fibers it activates
smallest increment of force that generates in a muscle
each muscle fiber has only one synapse

53
Q

Neuromuscular Junction (NMJ)

A

synapse/synaptic cleft between efferent/motor neuron and muscle fiber
muscle fiber is the post synaptic cell
directly gated chemical synaptic transmission - opening of calcium channels
motor end plate - region of muscle fiber plasma that lies directly under terminal axon

54
Q

Neuromuscular junction neutrotransmitter

A

Acetylcholine (ACH) - excitatory
binds to nicotinic receptors on postsynaptic membrane
nicotinic receptors open and allow Na+ to enter muscle cell (local depolarization)
no summation
no inhibitory transmitters

55
Q

Motor neuron (muscle efferent neuron)

A

muscle cell = postsynaptic cell
one axon terminal synapses with one muscle cell

56
Q

Transverse tubule (T-tubule)

A

extracellular space of muscle fiber that is positively charged with respect to negatively charged intracellular space

57
Q

Action potential with T-tubule

A
  1. conformational change in DHP receptor
  2. through foot process opens ryanodine receptor channel located in sarcoplasmic reticulum
  3. calcium rushed out of sarcoplasmic reticulum into cytosol of muscle cell
  4. calcium interacts with contractile elements to produce a contraction
58
Q

DHP receptor is physically coupled with _____

A

ryanodine receptor through foot process

59
Q

Sarcomere

A

structural unit of a myofibril striated muscle
bound on either side by Z-lines (network of proteins)
contractile elements are the myofilaments
thick filaments - myosin
think filaments - actin

60
Q

Myosin

A

forms thick filament
long tail with 2 globular heads (cross-bridges) attached to tails

61
Q

Globular head myosin binding sites

A

top of head - actin
based of head - ATP

62
Q

Myosin energy states

A

low energy state - head is bent and bound to ATP
high energy state - head if flat and bound to ADP

63
Q

Actin

A

primary protein in thin filament
binding site for myosin

64
Q

Tropomyosin

A

regulatory protein bound to actin
double helical shaped strand which wraps around actin and covers myosin binding sites

65
Q

Troponin

A

calcium is released by sarcoplasmic reticulum after action potential and binds to troponin
troponin moves tropomyosin away from blocked myosin sites

66
Q

Cross-bridge cycling

A
  1. calcium binds to troponin on thin filament causing tropomyosin to be dragged away and expose binding site
  2. high energy state ADP myosin binds to actin
  3. power stroke: myosin head pivots forward causing H zone to shorten, release of ADP
  4. low energy ATP myosin is bent forward and is released from actin
  5. re-energizing and repositioning of cross bridges and ATP converts to ADP
  6. removal of calcium ions back to sarcoplasmic reticulum, troponin/tropomyosin complex covers actin binding sites
67
Q

calcium pump

A

active transport with ATP
after muscle contraction is complete, calcium moves back into sarcoplasmic reticulum

68
Q

3 roles of ATP in muscle contraction

A
  • energizing power stroke of myosin cross-bridge
  • disconnecting myosin cross-bridge from binding site of actin
  • pumping Ca2+ back into sarcoplasmic reticulum
69
Q

2 types of muscle fibers

A

White: fast twitch, short lasting, large, high glycogen content, glycolysis, sprint
Red: slow twitch, long lasting, small, myoglobin, high blood supply, Krebs cycle and oxidative phosphorylation, endurance

70
Q

Myoglobin

A

primary oxygen carrying protein of muscle tissues

71
Q

Capillaries

A

bring oxygen to muscle cells

72
Q

Glyocgen

A

storage form of glucose, broken down to release glucose

73
Q

Glycolysis

A

use glucose to make ATP in absence of oxygen

Physiology 210 (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions