Excitation Contraction Coupling

Q. In a skeletal muscle, T – tubules

1. Secrete acetylcholine
2. Gives mechanical support
3. Conducts impulses forward
4. Bring about calcium flow for muscle contraction

Q. In the resting muscle fibre, tropomyosin partially covers

1. Myosin binding sites on actin
2. Calcium binding sites on troponin
3. Calcium binding sites on actin
4. Actin binding sites on myosin

Q.

At the neuromuscular junction, nerve impulses are carried across synaptic cleft by neurotransmitters.

1. True

2. False

Q.

WHICH OF THE FOLLOWING ION IS NECESSARY FOR THE CONTRACTION OF A MUSCLES & NERVE IMPULSE TRANSMISSION 1] Na+ 2] K+ 3] CA++ & Mg++ IONS 4] NONE OF THESE

Q. What happens when the calcium ion level increases in the sarcoplasm?

1. Filament sliding occurs
2. Filament sliding stops
3. Muscle relaxes
4. No change in muscle state

Q. briefly describe sliding filament theory

Q.

Describe the important steps in muscle contraction.

Q.

Define sliding filament theory of muscle contraction.