Muscles & Joints*

Question 1

What are the 3 muscle types found in the body?

Answer 1

Smooth muscle, Cardiac muscle, and skeletal.

Question 2

Explain cardiac muscle.

Answer 2

It is a modified skeletal muscle.
- It is found in the heart.
- Branched muscle fibres.
- Joined by intercalated discs.
- Short duration contractions
- Fatigue free.

Question 3

Explain smooth muscle.

Answer 3

• The majority of it is visceral muscles.
• Short oval cells.
• Contractile proteins and not arranged in regular patterns so appears smooth.
• Long sustained contractions.
• Under control of ANS.

Question 4

Explain skeletal muscle.

Answer 4

• Majority attached to bones.
• ## Under control of the somatic nervous system.

Question 5

Explain skeletal muscle.

Answer 5

• Majority attached to bones.
• Under control of the somatic nervous system.
• Regular arrays of contractile proteins.
• Relatively short contractions.

Question 6

Explain the structure of muscle fibres.

Answer 6

• Each cell/fibre is composed of many myofibrils.
• Each myofibril made up of myofilaments.
• Myofilaments contain actin and myosin

Question 7

Explain Type 1 skeletal muscle fibres.

Answer 7

They contain lots of mitochondria and capillaries.
Produce large amounts of energy slowly.
Aerobic metabolism (needs o2.
Fatigue resistant.
Slow contraction.
Contain myoglobin.

Question 8

Explain Type 2b fibres.

Answer 8

They use glycolytic metabolism.
Few capillaries, mitochondria, and little myoglobin.
Produce large amounts of energy quickly and rapidly contraction.
Susceptible to fatigue.

Question 9

Explain type 2a fibres.

Answer 9

Contain little amounts of myoglobin.
Have a more extensive capillary network.
A mixture of oxidative and glycolytic.
Contract rapidly.
Some resistance to fatigue.

Question 10

What are synovial joints?

Answer 10

They are formed between two or more bones enabling movement.

The shape of bones determines mobility and stability.