physiology

Question 1

what is the function of skeletal muscles

Answer 1

maintain posture
respiration
heat production (shivering)
metabolism
movement

Question 2

what are the 3 types of muscle

Answer 2

cardiac
skeletal
smooth

Question 3

describe cardiac muscle

Answer 3

striated and involuntary

Question 4

describe smooth muscle

Answer 4

non-striated and involuntary

Question 5

describe skeletal muscle

Answer 5

striated and voluntary

Question 6

what innervates cardiac muscles

Answer 6

ANS

Question 7

what innervates smooth muscles

Answer 7

ANS

Question 8

what innervates skeletal muscle

Answer 8

somatic nervous system,

Question 9

what is the transmitter at the skeletal muscle neuromuscular junction

Answer 9

acetylcholine

Question 10

what initiates skeletal muscle

Answer 10

neurogenic mechanism

Question 11

what initiates cardiac muscle

Answer 11

myogenic (pacemaker potenital)

Question 12

what is a motor neurone

Answer 12

a single alpha motor neurone and all the skeletal muscle fibres that it innervates

Question 13

what does the number of muscle fibres per motor unit depend on

Answer 13

the function served by the muscle. if precision is more important than power then there will be fewer fibres and vice versa

Question 14

how are skeletal muscles organised

Answer 14

whole muscle to muscle fibre to myofibrils to sarcomere which are made up of myosin and actin

Question 15

what is a myofibril

Answer 15

a specialised intracellular structure

Question 16

what is a functional unit

Answer 16

the smallest component capable of performing the functions of the organ

Question 17

where is a sarcomere located

Answer 17

between two z-lines

Question 18

what is a z-line

Answer 18

connects the thin filaments of two adjoining sarcomeres

Question 19

what are the 4 zones of a sarcomere

Answer 19

A-band
H-zone
M-line
I-band

Question 20

what is a A-band

Answer 20

thick filaments with portions of thin that overlap both ends of the thick

Question 21

what is the H-zone

Answer 21

lighter areas within the middle of the A-band where the thin filaments don’t reach

Question 22

what is the M-line

Answer 22

extends vertically down the middle of the A-band, within the centre of the H-zone

Question 23

what is the I-band

Answer 23

consists of the remains portion of thin filaments that don’t project onto the A-band

Question 24

how is muscle tension produced

Answer 24

the sliding of actin on myosin

Question 25

what is ATP needed for in muscle contraction

Answer 25

contraction
relaxation
to release cross bridges
pump Ca2+ back into the SR

Question 26

what is Ca2+ needed for in muscle contraction

Answer 26

switch on cross-bridge formation

Question 27

what is excitation contraction coupling

Answer 27

the process where the surface AP results in activation coupling of the contractile structures of muscle fibres

Question 28

explain muscle contraction

Answer 28

acetylcholine is released by the motor neurone
the surface AP spreads down the transverse T-tubles
this triggers the release of Ca2+ from the SR
Ca2+ binds to troponin which pulls the troponin-tropomysoin complex aside to expose the bind site
cross-bridge formation occurs