neuromuscular junction

Question 1

what is a refactory period

Answer 1

its a time during which an organ or cell is incapable of repeating a particular action

Question 2

absolute refractory cooresponds refers to

Answer 2

depolarization and repolarization

Question 3

relative refractory periods refer to

Answer 3

hyperpolarization

Question 4

what is twitch

Answer 4

this is a single rapid contraction and relaxation of a muscle fiber or a group of muscle fibers due to a sigle action potential of the motor neuron

Question 5

what happens in the latent period

Answer 5

this is the period btw when the stimulus is applied and when the first sign of the muscle contraction

Question 6

at what period does the excitation - contraction coupling takes place

Answer 6

latent

Question 7

what happens in the contraction period

Answer 7

this si the period btw the onset of the contractiona nd the endind of the contraction in which the peach tension occurs

Question 8

what happens in the relaxation period

Answer 8

period btw the time of the peak tension to the point when tension returns to baseline

Question 9

what are the other actions that takes place in the relaxation period

Answer 9

ca2 is being pumped back into the sacroplasmic reticulum
cross-bridge cycle stops
muscle is stretching back to its original length

Question 10

does a muscle contraction curve have a refractory period

Answer 10

NO

Question 11

what is excitation-contraction coupling

Answer 11

this is when an action potential causes depolarization in the myocyte membrane

Question 12

a partial state of contraction of a skeletal muscle to maintain its optimal length during resting condition, even when a force isapplied to elongate the muscle is what

Answer 12

muscle tone

Question 13

clinically muscle tone can be described as what

Answer 13

as the resistance, felt by the examiner during
passive stretching of a joint when the muscles are at rest

Question 14

features of the muscle tone

Answer 14

Essential for maintaining body posture.
Reflect a state of preparedness to a movement
Prevents hypermobility of joints
Declines during REM.

Question 15

types of hypertonia

Answer 15

spasticity
rigidity
spasm

Question 16

classification of muscle tone

Answer 16

postural and phasic

Question 17

truths about postural muscle tone

Answer 17

seen in axial muscles
gravity is an important factor
results from a steady stretch on the muscles
manifests as prolonged muscle contraction

Question 18

truths about the phasic tone

Answer 18

assesed clinically as a rapid and short duration
results from a rapd stretch of tendon

Question 19

muscle tone is regulated by what

Answer 19

spinal mechansim and supraspinal mechanisim

Question 20

spinal mechanism is dependent on the interaction betw what

Answer 20

muscle spindle
spinal cord
interneurons

Question 21

supraspinal is regulated by

Answer 21

facilatatory and inhibitory long tracts and cerebelum

Question 22

sudden rapid stretch of a muscle stimulates what

Answer 22

nuclear bag fibers and 1a afferents

Question 23

rapid stretch is the clinical bases of what

Answer 23

deep tendon reflex

Question 24

sustained stretch stimulates what

Answer 24

nuclear chaon fibers and type 2 a

Question 25

static stretch response is the physiological basis of what

Answer 25

maintainng muscle tone

Question 26

supraspinal control consist of

Answer 26

supraspinal control through descendong long tracts and cerebellum

Question 27

role of cerebellum

Answer 27

medaila part of the anterior lobe activates medullary reticular formation and inhibits muscle tone lateral part activates pontine reticular formation and facilitates muscle tone indirectly cerebellar lesions produce hypotonia

Question 28

hypertonic constsit of what

Answer 28

spasticity dystonia and rigidity

Question 29

the involuntary muscle hyperactivity consists of what

Answer 29

spasticity sensus strictu rigidity dystonia spasms

Question 30

postive consequences of spasticity

Answer 30

helps in standing and walking reduces edema delays muscle atrophy prevent osteoporosis aids in breathing

Question 31

A muscle with a shorter length and reduced cross-section produces what

Answer 31

less force