muscular system unit 5

Question 1

cardiac muscle

Answer 1

• loacted in heart only
• doesnt fatigue
• involuntary control
• bloody supply from coronary arteries

Question 2

smooth muscle

Answer 2

• located in walls of digestive and circulatory system
• doesnt fatigue
• involuntary
• vasoconstriction
• vasodilation

Question 3

skeletal muscle

Answer 3

• voluntary control
• connected to bones via tendons
• movement
• can fatigue during exercise
• create movements by making decisions

Question 4

type 1 slow twitch fibres

Answer 4

STRUCTURE
- small fibre size
- large mitochondria and capillaries
FUNCTION
- slow contraction speed
- low force produces
- high resistance to fatigue
- e.g marathon runners

Question 5

type 11a fibres

Answer 5

STRUCTURE
-large fibre size
- small number of mitochondria and capillaries
- low myoglobin
FUNCTION
- fastest contraction speed
- highest force produced
- lowest resistance to fatigue

Question 6

type 11b fibres

Answer 6

STRUCTURE
- large fibre size
- moderate mitochondira and capillaries
- moderate myoglobin
FUNCTION
- fast contraction speed
- low resistance to fatigue
- high force produced

Question 7

process of ramp like recruitment of muscle fibres

Answer 7

• all muscle fibres contribute the same amount of force during light effort
• when pace picks up ST fibres contribute first and around 60%
• FTa fibres then starts and contributes around 76%
• lastly FTb fibres start last and contribue around 92%
• continue to work at these percentages

Question 8

fliding filament theory

Answer 8

1) nerve impulse is recieved and calcium ions are released from the sarcoplasmic reticulum
2) calcium ions attach to troponin which change the shape of tropomyosin
3) binding sites are exposed which allows cross bridges to be formed between actin and myosin
4) this pulls the z lines closer together
5) the sarcomere shortens in length
6) h zone disappears and atp breaks down into energy to break the cross bridges
7) this produces a power stroke which occurs in the myofibril

Question 9

all or nothing law

Answer 9

• needs to be enough acetylcholine released to reach the threshold
• after this the motor unit will be stimulated
• not enough acetylcholine means the fibres wont contract
• enzyme atpase catalyses atp+h2o=adp+phosphate

Question 10

isometric contractions

Answer 10

• muscles under tension
• hold the body in 1 position
• muscles stay the same length

Question 11

isotonic contractions

Answer 11

• muscles shortens
• developing tension
• muscles become fatter and shorter
• upwards phase against gravity

Question 12

isotonic eccentric

Answer 12

• muscles lengthen
• under tension
• downwards phase

Question 13

deep muscles (7)

Answer 13

• transverse abdominals
• sternocleidomastiod
• rhomboid
• shoulder rotators
• erecor spinae
• wrist supinator
• wrist pronator

Question 14

agonist

Answer 14

contracts to produce a movement

Question 15

antagonist

Answer 15

relaxes to allow the movement to happen via the agonist

Question 16

fixator

Answer 16

reduces undesired movement using the next joint up from the moving joint

Question 17

synergist

Answer 17

muscle that aids the agonist by directing the movement

Question 18

flexion

Answer 18

decreases the angle at a joint

Question 19

extension

Answer 19

increases the angle at a joint

Question 20

abduction

Answer 20

taking limbs away from the midline

Question 21

adduction

Answer 21

bringing limbs in towards the midline

Question 22

horizontal flexion

Answer 22

decreasing the angle at a joint going across the midline

Question 23

horizontal extension

Answer 23

increasing the angle of a joint going away from the midline

Question 24

lateral flexion

Answer 24

decreasing the angle of the spine sideways

Question 25

sagittal plane

Answer 25

• flexion and extension ( forwards and backwards)
• splits body into left and right

Question 26

frontal plane

Answer 26

• abduction and adduction (in and out at the side )
• splits body into anterior and posterior

Question 27

transverse plane

Answer 27

• horizontal flexion, horizontal extension (spinning)
• splits body into superior and inferior