Brainscape's Knowledge GenomeTM

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


See full index

Human physiology > muscle stimulation > Flashcards

muscle stimulation Flashcards

1
Q

what regulates how big an axon will be?

A

the cell body

larger cell body means larger nucleus and larger muscle it ca innervate

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

what do large motor units innervate?

A

type IIB fibres: fast twitch glycolytic white

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

what do small motor units innervate

A

type I

slow twitch oxidative red muscles

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

define muscle tension

A

the force exerted by contracting muscle on a object

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

define load

A

the force exerted on muscle by a weight that need to be moved

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

developent of muscle tensio depends on?

A

the frequency of stimulation
sterngth of stimulation
degree of stretch

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

what is the latent phase?

A

no contraction

time taken for the impulse to rach to muscle

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

wha stages do muscles go through after a simple stimulus?

A

latent period
period of contraction
period of relaxation

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

whathapens during the period of contraction?

A

cross binding develops

sarcomre shortens

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

what happens in the relaxation period?

A

Ca levels in cytosol decrease due to SERA
cross bridges break
muscle returns to normal length

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

what is temporal summation?

A

second stimuli applied before relaxation period is finished then increased tensio develops

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

what happens if there is insufficient time between stimulations

A

subsequent twitches become larger
calcium not fully reteruned to base levels
contractions stronger, building
eventually reach a max tension though

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

what does repeated stimulation during relaxation periods cause?

A

results in a gradual increase in tension

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

what is incomplete or unfesed tetanus

A

repeated stimulation causing a gradual increase in tension resulting in a max tension of a bumpy plateau
there is a small amount of relaxation between each stimulus but not large

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

what is complete or fused tetanus

A

stimulation frequency is incrased before the relaxation period there are no signs of relaxation at all
complete tetnaus is reached
plateau is flat not bumpy

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

why in complete fused tetanus does there eventually come a fatigue period?

A

tension has to drop at soe point
lactic acid builds up leading to a pH drop
ATp is decerased
imbalance in ion concentrations

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

why are large cell bodys conected to large motor units

A

axon is bigger, ore dendrites and units that can be innervated

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

which motor units have the higher resistance

A

smaller cell bodys

larger ones have lots of ion channels and thus lower resitance, needs more to innervate it though

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

features of small motor units

A

higher resitance
low activation thersholds
innervated by small motor neurons
few ion channels

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

features of large motor units

A

low resistance
high activation thresholds
lots of ions channels
need longer stimulation

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

what does the sliding filament theory say about muscle tension

A

tension is related to the number of cross bridges that form

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

what is the length tension relationship?

A

everything, myosin and actin, need to be in optimal conformation in order for max tension
muscle keeps in optimal length by bones

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

what happens if muscle fibres arent in the correct conformation for contraction?

A

not as much tension or force is generated

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

what does anormal single stimualte do

A

gives single twitch

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

what does multiple well spaces stimuli cause?

A

same tension

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

what does repeatedn tension cause?

A

staircase effects

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

explain the staircase effect

A

levels of Ca not reduce fully to base line
muscle heats up
heat increases enzyme rates
heat makes muscle less stiff, energy used for contration and not to overcome the stiffness
basis of why we need to warm up

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

two types of contractions

A

isotonic and isometric

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

define isometric

A

same length contraction but tension changes

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

define isotonic

A

same tension constant force contractions

contraction reaches a level and stays the same but legnth changes

31
Q

how does an isometric contraction occur

A

connective tissue lengthens meaning the totoal muscle length remains the same

32
Q

define fulcrum

A

point of movement and attachement

33
Q

why have fulcrums

A

means smaller amounts of force are needed to move the joint than if the muscle was further away

34
Q

what prevents over stretching

A

sensors called proprioreceptrs

35
Q

where are proprioreceptos found

A

main muscles

interphase between musles adn tendons

36
Q

what do propriorecetors do

A

stop over stetching

cause activation of gamma neurones in over stretching to stop it going further

37
Q

what is the golgi tendon body?

A

sensory nerve endings between collagen fibres

38
Q

two types of propoceptors

A

muscle spindles and goldi tendor organs

39
Q

what are muscle spindles

A

burried among extrafusal fibres of the muslce and send infromation to the CNS about stretch

40
Q

structure of a muscle spindle

A

enclosed in connective tissue capsule called a sfusal

41
Q

difference between intrafusal and extra fusal fibres

A

extrafusal ones are for normal contractions

intrafusal ones are the spindles for stretch reception

42
Q

role of muscle spindles during relaxation

A

extrafusal fibres at rest
sensory neurones are always active sending signals to the CNS
alpha motor neurons ativated to recieve input from the sensory spindles to the contractile cells
extrafusal cells maintain cenrtain tension at rest

43
Q

what is the role of muscle spindles during stretch

A 
muscle stretches
spindles elonngate
increased signalling
alpha nuereosns more actiated
extrafusal fibres contract
stretching reduced and spindles return to original length
44
Q

how are muscle spindles used in reflexes

A

muscle spindles elongate and iniate action potential along sensory neurones
these go to the CNS and synapses to cause muscle to contract
no involve ment of the brain

45
Q

most common muscle spindle reflex

A

striking of the patella tendon leads to lengthening of the quadriceps muscles

46
Q

define GTO

A

golgi tendon organ
sensory neurone endings located between muscle fibres and tendons
proprioceptive sensory receptor organ that senses changes in muscle tension

47
Q

what does the GTO do

A

prevetns over contraction of the muscles

48
Q

how does the GTO work

A

sensory neurone activates inhibitory neurones in CNS

or inhibitory interneurons prevent activation of alpha neurones that would induce contraction

49
Q

what are the stimuli for hypertrophy

A

nutrition
hormones
stress

50
Q

what fibres are the mos trainable

A

type IIa
fst twitch oxidsative glycolyitc red muslce
they can take on characteritics of the other muscle type

51
Q

define hypertrophy

A

increasing muscle size

increase in both cross- sectional area, more fibrils but also more length, more sarcomeres per myofibril

52
Q

what is hyperplasia

A

number of muscle fibres increasing

not seen in adult humans

53
Q

what are satellite cells

A

stem cells for muscle repair

54
Q

how do satellite cells work?

A

when damage to the muscle is sensed they beocme activate
the muscles make signals to tell the cells to migrate tot eh region of damage
quiscent normally

55
Q

how does muscle hypertrophy occur?

A

fibres split a they get larger to maintain minimal surface area to volume ration
fibres stil share nuclei though

56
Q

why do muscle fibres want a minimal surface area to volume ratio

A

allows nutrients to get in and out efficiently

57
Q

what causes signals for muscles to grow?

A

nutrients
hormonal environment
mechanical load

58
Q

what do the signals for muscle growth then cause in the cells?

A

gene transcription
mRNA translation to increase myofibrillar protein content
more building blocks made
increases transciption

59
Q

what are steriods

A

chemical messengers that are syntehsised from cholesterol

act on the nucleus of cells

60
Q

what are anabolic steriods used for

A

enhance performance

maximise anabolic actions such as strength and muscle mass

61
Q

what is mypfascial pain syndrome

A

muscle tissue disorders

pain caused by tightened bands of muscle fibres

62
Q

what is fibromyalgia

A

chronic pain syndrome

affects mainly women

63
Q

what is muscular dytrophy

A

inherited muscle wasting diseased

muscle enlarge with fat and connective tissue

64
Q

what causes muscular dystrophy

A

mutation in dystrophyn
this protein connects muscle to ECM and transmits electrical activity to ECM
if the dystrophyn molecule isnt working properly there will be muscle damage

65
Q

what are UMN

A

upper motor neurones

originate in the bae of the cortext of the brain

66
Q

what are LMN

A

lower motor neurones

originate in the spinal cord

67
Q

what do UMn and LMN do?

A

act as transtters to provide a chain of command for voluntary movments to muscles throughout the body

68
Q

what happens in MND

A

motr neurone diease

chain of command between LMN and UMN brokwn as these neurones degenerate

69
Q

motor neurone disease risk factors

A

genetic
environmental
lifestyle

70
Q

what is ALS

A

amylotrophic lateral sclorsis

71
Q

what happens to the body in ALS

A

muscle degeneration caused by degeneration of the cell body, axon and nerve damage
stimulation decreases

72
Q

how does ALS manifest

A 
loss of strength
atrophy
twitches, fascicilations
muscle cramps
slow movements
loss of dexterity
73
Q

what happens with age

A

performance decreases
less motor units
less control

74
Q

what role do muscle injuries have with age

A

in old animals, more succeptable for contraction induce injury
they have a delayed and impaired recovery and structura and functional defects

Human physiology (21 decks)

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