Muscle

Question 1

What are the three types of muscle

Answer 1

Skeletal muscle
Cardinal muscle
Smooth muscle

Question 2

Key functions of skeletal muscle

Answer 2

Movement 
Stability of joints
Communication
Control of body openings 
Protection of internal organs 
Heat production 
Store for energy and protein

Question 3

Describe the macroscopic structure of skeletal muscle

Answer 3

Skeletal muscle has a myotendonous junction that connects the muscle to the tendon as well as an osteotendonous junction which connects the tendon to the bone.
Muscle is enshrsthed in deep fascia which is a connective tissue. Within the muscle is bundles of fascicles which are enshesthed in epimysium and perimyseium.

Question 4

Describe the microscopic structure of muscle

Answer 4

Inside fascicles are the myofers which are the muscle fibres/cells. The cells are multinuclei and are wrapped in endomysium. Within the cell are myofibrills which are bundles of myofillsments. Myofillsments are organise arrays of actin and myosin proteins in repeated pathways.

Question 5

Summarise contracting

Answer 5

The rivers make cross bridges which causes actin and myosin to overlap and shortening of the sacromere, and muscle to contract.

Question 6

Step one of bridge cycle

Answer 6

ATP binds to myosin head which causes dissolution of actin from the complex.

Question 7

Step 2 of bridge cycle

Answer 7

ATP is hydrolysed causing myosin to return to resting conformation.

Question 8

Step 3 of bridge cycle.

Answer 8

A cross bridge forms and myosin binds to a new head on actin.

Question 9

Step 4 of bridge cycle

Answer 9

P is released. Myosin head changes conformation resulting in power stroke. The filaments slide together.

Question 10

Step 5 of bridge cycle

Answer 10

ADP is erased

Question 11

Difference between hyaline and fibrocartilage

Answer 11

Hyaline cartilage moulders to the surface of bone createing a soft and frictionless surface for movement and its function is to resist compression.
Fibrocartlilage is founds at articulations that generally experience both compression and tension and it acts as shock absorbers that is able to distribute force over a wider area.

Question 12

Describe fibrous joints

Answer 12

Fibrous joint are made of DfCN and have a ligament structure. Their function is to limit movement and provide stability.

Question 13

Cartilaginous joints

Answer 13

Allow some movement, made up of fibrocartilage