neuro muscular physiology

Question 1

the type of contraction and the force required to resist an external load changes as …..

Answer 1

the joint angle changes

Question 2

what does the contraction type and force required depend on?

Answer 2

external force, or is less than internal force

Question 3

what needs to coordinate in joint angle

Answer 3

agonist and antagonist

Question 4

how does maximal force produced at a joint angle correspond too

Answer 4

maximal cross-bridge interaction

Question 5

what happens when the joint angle is too far apart

Answer 5

fewer cross bridges can form= less force

Question 6

what happens when the joint angle is optimal distance apart

Answer 6

maximal cross bridges form= max force

Question 7

what happens when the joint angle is too close together

Answer 7

cross bridges overlap= less force

Question 8

what is muscle cross sectional area (MCSA)

Answer 8

body mass (primarily muscle tissue) is correlated to strength

Question 9

what is the force- velocity relationship

Answer 9

as speed of movement increases the force a muscle can generate decreases

Question 10

what does as speed of movement increases the force a muscle can generate decreases

Answer 10

cross bridges are compromised

Question 11

muscle fiber types

Answer 11

type 1/ slow twitch
type2/ fast twitch

Question 12

what happens with fast twitch fibers

Answer 12

-greater force output
-greater overall speed of contraction
-greater fatigability

Question 13

what happens with slow twitch fibers

Answer 13

-lower force producing capacity
-slower contraction
-greater endurance

Question 14

how are your muscles affected with age

Answer 14

-effects force output
-loss of fast twitch fibres

Question 15

what is the difference in sexes

Answer 15

absolute force and power capacity of females is less than males

Question 16

how do the mechanical action of muscle contractions take place

Answer 16

sliding filaments theory

Question 17

what variables impact contraction forces

Answer 17

-joint speed
-speed/velocity of movement

Question 18

what initiates muscle contractions

Answer 18

the nervous system

Question 19

what are neural drives

Answer 19

neural impulses are electrical currents that pass along nerve fibres

Question 20

what does the nervous system deliver

Answer 20

brain delivers electricity to muscle to turn on

Question 21

what are motor nerves also known as

Answer 21

motoneurons

Question 22

characteristics of slow twitch motor nerves

Answer 22

-small diameter
-fatigue resistance
-100 muscle fibers

Question 23

characteristics of fast twitch motor nerves

Answer 23

-large diameter
-fatigue quickly
-500 muscle fibers

Question 24

where do impulses arrive

Answer 24

neuro-muscular junction

Question 25

where does the neuro muscular junction cross

Answer 25

crosses the synaptic cleft with aid of neurotransmitter

Question 26

where does the impulse travel

Answer 26

over sarcolemma through the t-tubules causing calcium to release from storage in sarcoplasmic reticulum

Question 27

what happens when calcium is released

Answer 27

causes molecular crossbridging of actin and myosin

Question 28

what happens in the absence of neural impulses

Answer 28

calcium is reabsorbed and stops the contraction

Question 29

what happens in the absence of neural impulses

Answer 29

calcium is reabsorbed and stops the contraction

Question 30

what is the cerebral cortex responsible for

Answer 30

plans and initiates voluntary motor activity

Question 31

what is the cerebellum responsible for

Answer 31

coordinates complex motor patterns

Question 32

what is the lower medulla responsible for

Answer 32

respiratory reflexes

Question 33

what is the brain stem and spinal cord responsible for

Answer 33

simple canial and spinal reflexes