Muscle(1)

Question 1

What are the 3 different types of muscle?

Answer 1

Smooth
Cardiac
Skeletal

Question 2

What is the structure of smooth muscle?

Answer 2

Long and slender cells
Cells arranged along, across and obliquely across the length of tubes
Irregularly shaped
Create a narrowing of tubes

Question 3

Where is smooth muscle found?

Answer 3

Surrounding all tubes in the body

E,g blood vessels, digestive system, reproductive system and respiratory system

Question 4

What is smooth muscle?

Answer 4

Involuntary muscle stimulated by the autonomic nervous system

Question 5

Where is cardiac muscle found?

Answer 5

In there heart

Question 6

What is the structure of cardiac muscle?

Answer 6

Strained in appearance

All or nothing contraction

Question 7

How is the cardiac muscle stimulated ?

Answer 7

Has no nervous input

Intrinsically activates through the Sino atrial (SA) node -> AV node -> purkinje fibres

Question 8

What is skeletal muscle?

Answer 8

Brings about movement to the skeleton

Voluntary muscle

Question 9

What is the structure of skeletal muscle?

Answer 9

Striated and rectangular arrangement

Fibres contract and shorten along their length

Question 10

Describe the components of the skeletal muscle outer sheaths

Answer 10

Endomyosium
Perimysium
Epimysium

Question 11

What is the structure of skeletal muscle fibres?

Answer 11

Muscle fibre -> fascicles -> muscle

Question 12

Briefly describe sliding filament theory?

Answer 12

1. Myosin heads hydrolyse ATP and become reorientated and energised
2. Myosin heads bind to the actin filaments creating cross bridges
3. Myosin heads rotate towards the centre of the sarcomere = THE POWER STROKE
4. As myosin heads bond ATP, the cross bridges attach from the actin

Question 13

Describe the Excitation-Contraction Process?

Answer 13

1. Nerve impulse - action potential
2. Sacroplasmic reticulum excitation
3. Calcium release
4. Contraction Phase
5. ATP-ADP hydrolysis (breakdown)
6. Actin and Myosin cross bridges

Question 14

What are slow twitch fibres?

Answer 14

Type 1

Question 15

What are fast twitch fibres?

Answer 15

Type 2

Question 16

What is type 2a?

Answer 16

Fast oxidative glycolytic

Question 17

What is type 2b?

Answer 17

Fast glycolytic

Question 18

What energy system does type 1 use?

Answer 18

Aerobic

Fat source

Question 19

Describe type 1 fibres?

Answer 19

Slow to contract
Low/moderate tension/force
Small in diameter
Can sustain contraction over extended periods (resistant to fatigue) aka endurance

Question 20

Describe the structure of type 1 fibres?

Answer 20

Good supply of capillaries
Red in colour
O2 available for ATP resynthesis
Mitochondria can be increased in size by endurance training
Have a high myoglobin store

Question 21

Describe type 2 a fibres?

Answer 21

Using the glycolytic/anaerobic energy system

Glucose as an energy source

Question 22

What force does type 2a exert?

Answer 22

High muscular force
Less resistant to fatigue
Can resynthesises ATP aerobically and anaerobically

Question 23

What are 2 b fibres?

Answer 23

Using the ATP-PC energy system

ATP as an energy source

Question 24

What are 2 b fibres good at?

Answer 24

Rapid speed of contraction
Low myoglobin content
Not good at endurance
Weight lifting, sprinting etc

Question 25

Describe the structure of 2b fibres?

Answer 25

Large cross sectional diameter

Low myoglobin content