muscle

Question 1

where does skeletal muscle occur

Answer 1

at the joints of a skeleton

Question 2

what is the name of the pairs which muscles are arranged in

Answer 2

antagonistic pairs, when one contracts the other elongates

Question 3

each skeletal muscle fibre is multinucleate, what does that mean

Answer 3

multinuclate- contains many nuclei

Question 4

what is the name of the plasma membrane structure which surrounds the muscle fibres

Answer 4

sarcolemma

Question 5

what is the muscle cytoplasm which is within muscle fibres called

Answer 5

sarcoplasm

Question 6

what is held in the sarcoplasm

Answer 6

sarcoplasmic reticulum
many mitochondria

Question 7

what are skeletal muscles arranged in

Answer 7

myofibrils

Question 8

what are myofibrils divided into

Answer 8

sarcomere

Question 9

what are the two protein filaments which allow muscle contraction

Answer 9

myosin
actin

Question 10

what are the three types of muscle

Answer 10

smooth
cardiac
skeletal/ striated

Question 11

is smooth muscle voluntary or involuntary

Answer 11

involuntary

Question 12

describe smooth muscle contraction

Answer 12

slow contraction
regularly contracts
doesnt tire quickly

Question 13

what nervous system controls smooth muscle

Answer 13

autonomic nervous system

Question 14

is smooth muscle multinucleate

Answer 14

no it contains one nucleus for each muscle cell

Question 15

where is smooth muscle found

Answer 15

digestive system
blood vessels

Question 16

what does cardiac muscle form

Answer 16

the muscular part of the heart

Question 17

describe cardiac muscle structure

Answer 17

corss bridges between fibres
intercalated discs to join muscle cells
contraction is a squeezing action

Question 18

what do intercalated discs do and what muscle do they belong to

Answer 18

intercalated discs is a specialised plasma membrane which are fused to produce junctions which allow diffusion of ions between muscle cells.

Easy transmission of action potential along cardiac muscle fibres

Question 19

does cardiac muscle fatigue easily

Answer 19

no

Question 20

what controls the rate of contraction of cardiac muscle

Answer 20

SAN

Question 21

what is the word used to describe cardiac muscle

Answer 21

myogenic- initiates its own contraction

Question 22

how does cardiac muscle appear under a microscope

Answer 22

striated with gaps, not in straight lines, with gaps in between rows of striated muscle

Question 23

what is the neuromuscular junction

Answer 23

the junction between the nervous system and a muscle is a neuromuscular junction

Question 24

what is stimulation of contraction

Answer 24

1- action potential arrives at the end of the axon and calcium ion channels open in the membrane, calcium diffuses in.

2- acetylcholine vesicles move towards and fuse with the end membrane through exocytosis

3- acetylcholine molecules diffuse across the gap and fuse with sarcolemma receptors

4- sodium ion channels open and sodium ions and diffuse into the muscle fibre and depolarise the sarcolemma

5- wave of depolarisation spreads along sarcolemma and down tranverse tubules into muscle fibre

Question 25

what is a transverse tubule

Answer 25

they are deep invaginations of the sarcolemma in muscle cells which facilitate transmission of action potential and muscle contraction.

Question 26

what is a motor unit

Answer 26

when many motor neurones divide and connect to several muscle fibres, they then contract together and provide a stronger contraction

Question 27

what are differences between a neuromuscular junction and a synapse

Answer 27

neuroM junctions-between a neurone and a muscle A synapse is between neurone and neurone neuromuscular junctions use t tubules to carry signals quickly, synapses dont

Question 28

what are similarities between neuromuscular junction and cholinergic synpases

Answer 28

both use acetylcholine both therefore use acetlycholinesterase to prevent constant impulses both triggered by action potentials in presynaptic membrane both use sodium ion channels and chloride ion channels

Question 29

what muscle groups do myofibril belong to

Answer 29

skeletal