1

Question 1

autonomic NS innervates which muscle types?

Answer 1

cardiac and smooth

Question 2

somatic NS innervates what muscle types

Answer 2

skeletal

Question 3

which muscle type is not striated

Answer 3

smooth

Question 4

define a motor unit

Answer 4

single alpha motor neuron and all skeletal muscle fibres it innervates

Question 5

which type of muscles have fewer fibres per motor unit

Answer 5

those for finer movements

Question 6

sequence of muscle organisation large to small

Answer 6

whole muscle > muscle fibre > myofibril > sarcomere

Question 7

skeletal muscle = ____ innervation

Answer 7

neurogenic

Question 8

which muscle type are neuromuscular junctions present

Answer 8

skeletal

Question 9

which muscle type is gap junctions present

Answer 9

cardiac

Question 10

cardiac muscle =___ innervation

Answer 10

myogenic

Question 11

what causes contraction in skeletal muscle

Answer 11

calcium release from sarcoplasmic reticulum

Question 12

what causes contraction in cardiac muscle

Answer 12

Ca++ from ECF and then sarco (Ca++ induced Ca++ release)

Question 13

what is functional unit of muscle

Answer 13

sarcomere

Question 14

4 zones of sarcomere

Answer 14

A-band
i-band
H-zone
M-line

Question 15

what is M-line

Answer 15

vertical line down middle of H-zone

Question 16

what is H-zone

Answer 16

middle of band where thin filaments dont reach

Question 17

what is I-band

Answer 17

remaining thin filaments that are not in band

Question 18

what is A-band

Answer 18

thick filaments (some thin)

Question 19

graduation of skeletal muscle contraction due to

Answer 19

motor unit recruitment and summation of contraction

Question 20

sarcomere is located between what

Answer 20

between 2 Z-lines

Question 21

skeletal muscle tension influenced by what

Answer 21

frequency of stimulation
summation of contraction
length of muscle fibres
thickness of fibres

Question 22

what prevents muscle fatigue

Answer 22

motor unit recruitment

Question 23

what can lead to a strong contraction

Answer 23

twitch summation (before first twitch relaxes)

Question 24

tenus is

Answer 24

max sustained contraction due to rapid stimulation with no relaxation between

Question 25

when will you get max tetanic contraction

Answer 25

when muscle is at optimal length (lo) before onset of contraction

Question 26

2 types of contraction

Answer 26

isotonic (movement) - length change | isomeric (posture) - constant muscle length

Question 27

velocity of muscle shortening ____ with load

Answer 27

decreases

Question 28

what is stretch reflex

Answer 28

is neg feedback to maintain optimal resting length

Question 29

stretch reflex pathway

Answer 29

1) stretch activates sensory receptors in muscle spindle causing increased firing of afferent neurons 2) afferent neurons synapse in cord with alpha motor neurons (efferent) 3) stretched muscle contracts (with simultaneous relaxation of antagonist muscles)

Question 30

what are muscle spindles

Answer 30

collection of specialised muscle fibres (intrafrusal fibres) that act as stretch receptors **normal muscle fibres are called extrafrusal fibres**

Question 31

sensory nerve ending of spindle fibre called?

Answer 31

annulospiral fibres

Question 32

spindle fibre have own efferent (motor) nerves called....

Answer 32

gamma motor neurones (these adjust tension)

Question 33

immediate source of ATP in muscles from?

Answer 33

creatine phospate to ATP

Question 34

when do you get glycolysis (glucose > pyruvate releasing ATP)

Answer 34

when no O2 present

Question 35

3 types of skeletal muscle

Answer 35

type 1: slow oxidative type IIa: fast oxidative type IIx: fast glycolytic

Question 36

type 1 muscle speed

Answer 36

slow twitch

Question 37

type IIa muscle speed

Answer 37

intermediate twitch

Question 38

type IIx muscle speed

Answer 38

fast twitch

Question 39

conditions in which each of the 3 muscle fibre types work

Answer 39

type 1: aerobic type IIa: both aerobic and anaerobic type IIx: anaerobic

Question 40

type of work each type of muscle fibre does

Answer 40

type 1: prolonged low work type IIa: prolonged moderate type IIx: short term high intensity