Muscular Structure

Question 1

Give examples of the three muscle types?

Answer 1

Involuntary - liver, kidney, lungs, gut
Cardiac - heart
Skeletal - everything else

Question 2

What other name is skeletal muscle referred too and give a description of how they work?

Answer 2

Striated muscle and they are consciously controlled

Question 3

Name the four Quad muscles and describe where they are?

Answer 3

Vastus lateralis is on the outside
Vastus medialis is on the inside
Vastus intermedius is underneath the rectus
femoris

The rectus femoris is on the front

Question 4

Name the three hamstring muscles and describe where they are?

What 4 other muscles are associated with the leg?

Answer 4

Bicep femoris is on the outside
Semimembranosis is on the inside
Semitendinosus is in the middle

Tibialis anterior is on the front of the tibia
Tibialis posteria is on the back of the tibia

Sternocleidomastoid - sternum and clavicle

Gastocnemius - calf

Question 5

Name the three skeletal muscle fibres and describe each?

Answer 5

Type 1 (slow twitch fibres) oxidative (red)
contract slowly, exert less force,
aerobic endurance
Type 2a (fast twitch fibres) oxidative/glycolysis
(white) contract quicker than slow,
more force, fatigue quicker, aerobic
and anaerobic although more
anaerobic
Type 2b (fast twitch fibres) glycolytic (white)
contract quickly, large force,
anaerobic, fatigue extremely quickly

Question 6

How do muscles contract (using the sliding filament theory)?

Answer 6

Muscle - epimysium - muscle fibers - muscle
(connective) fiber -
(fasciculi bundle) (cell)

myofibril - sarcomere -
(sarcoplasmic reticulum
releases calcium)
actin filament (thin) -
myosin filament (thick)
‘cross
bridges’ - (pull actin across myosin)

Question 7

Name the types of Muscular contraction?

Answer 7

STATIC
Isometric - pushing against a fixed object
does not change length

DYNAMIC
Concentric - agonist shortens during activation,
antagonist lengthens during
relaxation

ECCENTRIC - agonist lengthens during
activation, antagonist shortens
during relaxation

ISOKINETIC - agonist contracts or lengthens at
constant speed

ISOTONIC - agonist contracts or lengthens
according to demand of
movement

Question 8

Name the Muscle actions?

Answer 8

Antagonist muscle action - work in pairs

Agonist (prime mover) - active muscle

Antagonist - relaxes as movement occurs

Fixator - holds joint in position

Synergist - holds body position

Question 9

Name the short term effects of exercise on the muscle?

Answer 9

Produce heat - blood runs more smoothly
- ATP reactions/use up energy
fuels
- cool body down (sweat)
Capillary dilation
Produce movement/become more efficient

Question 10

Name the three adaptations that can occur in the muscle during exercise?

Answer 10

Aerobic

Occurs in the muscle
Slow twitch muscle fibres will enlarge
- increase in size and number of mitochondria
Greater potential for aerobic energy

Aerobic

Increase activity of (oxidative) enzymes
Hypertrophy of slow twitch muscle fibres leads to an increase in stores of glycogen
Increase in myoglobin
More O2 can be transported to the mitochondria

Anaerobic

Hypertrophy of fast twitch fibres
Increases levels of ATP and PC
Increase glycolytic capacity - improves muscle
ability to break down glycogen in absence of
O2
Exercise for longer without getting fatigued

Question 11

What do the ‘cross bridges’ do?

Answer 11

Cross bridges pull actin across myosin

Myosin have binding sites that allow connection to the actin in the crossbridge

Calcium deposits allow ‘traction’ and movement of the crossbridge

Question 12

Name the three muscle types?

Answer 12

Involuntary
Cardiac
Skeletal