Neuromascular sysytem

Question 1

Myosin heads only

Answer 1

H-zone

Question 2

M-line

Answer 2

Centre of sarcomere where myosin binds

Question 3

Protein responsible for elasticity

Answer 3

Titin

Question 4

Site of signal exhange

Answer 4

Neuromascular junction

Question 5

Zone of overlap function

Answer 5

A region where actin and myosin overlap
Site of where filament movement begins

Question 6

General mechanism of muscle contraction

Answer 6

-AP arrives at the presynaptic membrane
-Opens voltage-gated channels, Calcium enters
-Fusion of vesicles with pre-synaptic membrane is triggered
-Neurotransmitters diffuse and bind and activate to specific receptors in post synaptic cell
-It breaks down and taken up by postsynaptic terminals or other cells away from synapse.

Question 7

Contraction/ sliding mechanism

Answer 7

-AP arrives at T-tubules
-activates DHP receptors to
-open calcium channels and are released to ZONE OF OVERLAP
-Calcium binds to troponin and expose binding site
-forms cross bridges during attachment
-Power stroke occurs until ATP binds and terminates crossbridge.

Question 8

Isometric

Answer 8

No change in length

Question 9

Isotonic

Answer 9

Change in length but not tension

Question 10

Hypertrophy

Answer 10

SGORA- increased no. of myosin and actin
Muscle mass increases

Question 11

Dark bands

Answer 11

A-bands , myosin and actin

Question 12

Light bands

Answer 12

I-bands, actin

Question 13

Path taken by calcium ions

Answer 13

From sarcoplasmic reticulum to T tubules