Brainscape's Knowledge GenomeTM

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


See full index

LECTURE: Physiology > Chapter 2: Neromuscular Physiology > Flashcards

Chapter 2: Neromuscular Physiology Flashcards

1
Q

It is the result of the concentration difference of ions across a selectively permeable membrane that is caused by diffusion.

A

MEMBRANE ACTION POTENTIAL

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

This are rapid changes in the membrane potential that spread rapidly along the nerve fiber membrane

It begins with a sudden change from the normal resting negative membrane potential to a positive potential and ends vice versa.

A

ACTION POTENTIAL

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

Resting membrane potential before the action potential begins.

Polarized stage

A

RESTING STAGE

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

Rise of the potential in the positive direction caused by SODIUM inflow

A

DEPOLARIZATION

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

Re-establishment of the normal negative resting membrane potential (RMP).

A

REPOLARIZATION

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

An overshoot of the RMP toward negativity.

A

HYPERPOLARIZATION

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

These are necessary actors in causing depolarization and repolarization.

A

VOLTAGE GATED Na AND K CHANNELS

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

When the membrane potential becomes less negative, it activates the activation gate causing sodium ions to pour inward.

A

ACTIVATION

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

The same stimuli for activation also closes the inactivation gate. However, closes a few 10,000ths of a second after the activation gate open.

A

INACTIVATION

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

Gate of the potassium channel is closed and potassium ions are prevented from passing through.

A

RESTING STATE

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

When the membrane potential becomes less negative causing opening of the gate to allow potassium diffusion. However, it happens with a delay.

A

SLOW ACTIVATION

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

What is the threshold for stimulation?

A

-65mV

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

Required sudden rise is?

A

15 - 30mV

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

Any initial rise in the membrane potential will lead to a?

A

positive feedback cycle that would open the sodium channels.

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

Rising voltage in MP causes

A

more Na channels to open.

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

Excitable membrane excites adjacent membranes

An action potential elicited at any one point on an excitable membrane usually excites adjacent portions of the membrane

A

PROPAGATION OF ACTION POTENTIAL

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

Nerve of Muscle Impulse

A

A segment of the membrane is depolarized

Positive** charges spread** 1-3mm through the fiber

Rise in membrane potentials leads to a positive feedback cycle

Newly depolarized areas produce more local circuits and travels the length of the fiber.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

It occurs through the mechanism of Na-K pump

A

RE-ESTABLISHING RMP

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

Either all depolarized or none depolarized

The depolarization process travels over the entire membrane if conditions are right, but it does not travel at all if conditions are not right.

Allows the spread of depolarization to stop.

A

ALL OR NOEN PRINCIPLE

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

Low membrane potential can not fully close the gates

A

REPETITIVE DISCHARGE

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

is due to K leak channels

A

HYPERPOLAROZATION

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

REPETITIVE DISCHARGE

A

A low membrane potential leads to** influx of sodium and calcium**

Action potential occurs and membrane repolarizes

Hyperpolarization causes a delay before depolarization occurs again.

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

The potential remains near the peak of the potential for many milliseconds before repolarization begin.

A

PLATEAU

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

slow opening allows for prolonged
depolarization

A

CALCIUM (slow) CHANNELS

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

slow activation
leads to delayed repolarization

A

POTASSIUM CHANNELS

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

Viscid intracellular fluid

A

AXOPLASM

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

Its membrane is the one that conduct the action potential.

CENTRAL CORE

A

AXON

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

Has Myelin Sheath → electrical insulator
*
Has Node of Ranvier →uninsulated area
between sheaths
*
Seen in large fibers
*
Conduction velocity: 100 m/sec

A

MYELINATED FIBERS

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

Flow of electric currents through the Nodes of Ranvier only allows impulse to jump along the fiber.

Increases velocity of impulses and conserves energy for the axon

A

SALTATORY CONDUCTION

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

Has no Myelin Sheath
*
Has no Node of Ranvier
*
Seen in small fibers
*
Conduction velocity: 0.25 m/sec

A

UNMYELINATED FIBERS

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

Stimuli that barely reached the level required to elicit an action

Below the stimuli

A

ACUTE SUBTHRESHOLD POTENTIAL

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

Stimuli that barely reached the level required to elicit an action potential, but occurs only after a latent period.

A

THRESHOLD POTENTIAL

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

A new action potential cannot occur in an excitable fiber as long as the membrane is still depolarized

A

REFRACTORY PERIOD

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

period during which a second action potential cannot be elicited even with a strong stimulus.

A

ABSOLUTE REFRACTORY PERIOD

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

period after the absolute refractory wherein a second action is inhibited, but not impossible to elicit

A

RELATIVE REFRACTORY PERIOD

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

Thin membrane covering the muscle fiber which fuses a tendon fiber at the end of each muscle

A

SARCOLEMMA

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

MUSCLE COMPOSITION

A

MUSCLE–> FASCICLE–> MUSCLE FIBER–> MYOFIBRIL

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

covering of each muscle

A

EPIMYSIUM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

covering of each fascicle

A

PERIMYSIUM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

covering of each myofibril

A

ENDOMYSIUM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

A springy protein that maintains the side- by-side relationship of actin and myosin

A

TITIN

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

ntracellular fluid in the spaces between the myofibrils

A

SARCOPLASM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Regulates calcium storage, release and reuptake

A

SARCOPLASMIC RETICULUM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

A portion of the myofibril that lies between two successive Z disks

38
Q

Also known as the thick filament

Anisotropic (A) bands

It has cross bridges

39
Q

contains myosin as well
as some actin filaments

A

ANISOTROPIC (A) BANDS

40
Q

Also known as the thin filament

Isotropic (I) bands

41
Q

composed oF pure actin
filaments

A

ISOTROPIC (I) BANDS

42
Q

proteins that passes crosswise across the myofibril and attaches the myofibrils to one another

43
Q

Area of pure myosin

44
Q

a line that bisects the H Zone

45
Q

Myosin molecules are composed of two heavy chains and four light chains.

A

TAIL & HEAD

46
Q

two heavy chains wrapped spirally around and forms a double helix

47
Q

composed of 2 heads and each is formed by 2 light chains and the end of the heavy chains is folded bilaterally

48
Q

tails of the myosin molecules bundled together

49
Q

part of the bodies of each myosin molecule

50
Q

protrude to the sides

51
Q

collective term for the arm and head

A

CROSS-BRIDGES

52
Q

flexible points of the cross-bridges; exit and head

53
Q

it is the backbone of the filament

54
Q

it serves as attachment for ADP molecules

55
Q

it is wrapped around F-actin; at rest, it lies on top of the active binding sites of actin strands

A

Tropomyosin

56
Q

it is attached to the tropomyosin and is believed to attach tropomyosin to actin

57
Q

has high affinity for actin

A

TROPONIN I

58
Q

has high affinity for tropomyosin

A

TROPONIN T

59
Q

has high affinity for calcium

A

TROPONIN C

60
Q

inhibits actin and myosin via calcium ions

A

TROPONIN- TROPOMYOSIN COMPLEX

61
Q

GENERAL MECHANISM OF MUSCLE CONTRACTION

A

Action potential travels along a motor nerve to its endings causing Ach release

Ach binds with Ach channels causing Na to diffuse inside muscle membrane leading to another action potential

Action potential travels through the center of the fiber activating the sarcoplasmic reticulum to release Ca

Ca causes the actin and myosin to slide alongside each other causing contraction

Ca is pumped back and stored until it is used again. This causes cessation of contraction.

62
Q

MOLECULAR CONTRACTION: THE SLIDING FILAMENT THEORY

A

ATP binds with the heads of the cross bridges and is cleaved, but cleaved products remain in the head

**Calcium bonds with the troponin-tropomyosin complex **uncovering the active sites causing actin and myosin bond

Power stroke and Walk-along mechanism takes place

Once power stroke occurs, cleaved products are released causing detachment of the head from the actin

Release of cleaved products causes attachment and cleavage of a new ATP leading to new energy causing again a power stroke

Cycle continues until the actin pulls the Z membrane up against the ends of the myosin or the load becomes too great

63
Q

is produced when the
sarcomere is at 2.0-2.2 micrometers

produced at normal length and 2x length

A

MAXIMUM TENSION

64
Q

produced when the muscle is** fully shortened or fully lengthened**

when length is ½ normal

A

MINIMAL TO NO TENSION

65
Q

RELATIONSHIP WITH LOAD

A

Velocity of contraction is inversely proportional with load.

66
Q

Muscles do not shorten or lengthen
during contraction

67
Q

Muscles shorten or lengthen but the tension remains constant throughout contraction

68
Q

Muscle lengthens throughout the contraction

69
Q

Muscle shortens throughout the contraction

A

CONCENTRIC

70
Q

It is identified as all muscle fibers innervated by a single nerve fiber depending on the function of the muscle.

A

Motor Unit

71
Q

Small motor units are stimulated in preference of larger units initially

A

SIZE PRINCIPLE

72
Q

When a muscle begins to contract after a long period of rest, its initial strength of contraction may be as little as one half its strength 10 to 50 muscle twitches later

A

TREPPE (STAIRCASE EFFECT)

73
Q

It is the adding together of individual twitches to increase the intensity of overall muscle contraction.

74
Q

Increasing the number of motor units contracting

A

MULTIPLE FIBER SUMMATION

75
Q

Increasing the frequency of contraction

A

FREQUENCY SUMMATION

76
Q

A single, sudden contraction lasting a fraction of a second

77
Q

Completely smooth and continuous muscle contraction due to rapid contractions fusing together

78
Q

Rapid, irregular and unsynchronized contraction that can be seen

A

FASICULATION

79
Q

Rapid, irregular and unsynchronized contraction that cannot be seen

A

FIBRILLATION

80
Q

Tautness of muscles even at rest
*
It results from a low rate of impulses coming from the spinal cord.

A

MUSCLE TONE

81
Q

Results mainly from inability of the contractile and metabolic processes of the muscle to continue supplying the same work output

A

MUSCLE FATIGUE

82
Q

leads to almost complete muscle fatigue within 1 to 2 minutes

A

INTERRUPTION OF BLOOD FLOW

83
Q

Increase of the total mass of a muscle
*
It is due to repeated forceful contractions
*
Increased synthesis of muscle contractile proteins, splitting of myofibrils and increase in glycolytic enzymes

A

HYPERTROPHY

84
Q

Decrease of the total mass of a muscle
*
It is due to a muscle disuse or denervation

85
Q

Increase in the number of muscle fiber

A

HYPERPLASIA

86
Q

Replacement of contractile tissue with fibrous tissue or fatty tissue.

A

CONTRACTURE

87
Q

False increase in muscle mass
*
Due to the replacement of muscle with fibrous or fatty tissue

A

PSEUDOHYPERTROPHY

88
Q

Muscle contracture in dead caused by loss of ATP

A

RIGOR MORTIS

89
Q

Internal extensions which penetrates the muscle fiber in order to allow propagation of action potential

90
Q

Regulates calcium release, storage and
reuptake

A

Sarcoplasmic Reticulum

91
Q

Excitatory neurotransmitter that excites the muscle fiber membrane

A

ACETYLCHOLINE

92
Q

It destroys acetylcholine

A

ACETYCHOLINESTERASE

93
Q

Pumps calcium back to the sarcoplasmic reticulum

A

CALCIUM PUMP

94
Q

Composed of discrete, separate smooth muscle

Example: Ciliary muscle of the eye, iris muscle of the eye, piloerector muscles

Each fiber is Separated from each
other by a thin layer of membrane

A

MULTI-UNIT

95
Q

Also called syncytial or visceral smooth muscle

Contain gap junctions

mass of smooth muscle fibers that
contract together as a single unit

96
Q

Cardiac Muscle is composed of three (3) major types

A
  1. ATRIAL MUSCLE
  2. VENTRICULAR MUSCLE
  3. CONDUCTIVE MUSCLE FIBERS
97
Q

Exhibit automatic rhythmical electrical discharge in the form of AP or conduction of the AP through the heart and contract only feeble

A

CONDUCTIVE MUSCLE FIBERS

98
Q

Cell membranes that separate individual cardiac muscle cells from one another

A

INTERCALATED DISCS

99
Q

Permeable communicating junctions that allow rapid diffusion of ions
*
Allow ions to move with ease so that action potentials travel easily

A

GAP JUNCTION

100
Q

Collection of cells that work together such as the cardiac muscle

101
Q

2 syncytium in the heart

A
  1. ATRIAL
  2. VENTRICULAR
102
Q

ACTION POTENTIAL IN CARDIAC MUSCLE

A

Phase 0 (Depolarization)
Fast Na channels open, Na influx
*
Phase 1 (Initial Repolarization)
Fast** K** channels open, K efflux
*
Phase 2 (Plateau)
Ca channels open and K channels close, Ca influx
*
Phase 3 (Rapid Repolarization)
Ca channels close and slow K channels open, K efflux
*
Phase 4 (RMP)
Around -88 mV or -90 mV

LECTURE: Physiology (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions