Neuromuscular Junction

Q.

Briefly describe a neuromuscular junction.

Q.

Given below is a randomly arranged list of events that occur at the neuromuscular junction to trigger muscle contraction.Which of the following gives the correct sequence of these steps?

(i) Acetylcholine binds to the receptor sites on sarcolemma

(ii) Nerve impulse

(iii) Release of Ca+2 from sarcoplasmic reticulum

(iv) The neurotransmitter acetylcholine is released

(v) Sarcomere shortens

(vi) Acetylcholine diffuses across the synaptic cleft

(vii) Spread of impulses over sarcolemma on T-tubules

1. (vii), (vi), (v), (iv), (iii), (ii), (i)

2. (ii), (iv), (i), (vi), (vii), (iii), (v)

3. (ii), (iv), (vi), (i), (vii), (iii), (v)

4. (i), (ii), (iii), (iv), (v), (vi), (vii)

Q.

During an action potential, what is the role of calcium?

1. The calcium removes the tropomyosin block.

2. The calcium binds to the actin and myosin and makes them work together.

3. The calcium causes the release of acetylcholine.

4. The calcium breaks apart ATP to ADP and P.

Q. Immediate source of energy for muscle contraction is

1. Creatine phosphate
2. GTP
3. Glucose
4. ATP

Q.

Read the following statements about muscle contraction in humans:

i. Chemical energy is converted into mechanical energy during muscle contraction

ii. Acetylcholineeasterase is an enzyme that catalyzes the production of acetylcholine

iii. In a contracted muscle, volume remains the same.

iv. A contracted muscle becomes shorter and thicker.

1. only iv) is correct.

2. only i) and iv) are correct.

3. only ii), iii) and iv) are correct.

4. only i), iii) and iv) are correct.

Q.

Stimulation of a muscle fiber by a motor neuron occurs at

1. The neuromuscular junction

2. The transverse tubules

3. The myofibril

4. The sarcoplasmic reticulum

Q.

The Junction between a nerve cell and the motor unit is called

1. Creatine phosphate

2. Synapse

3. Neuromuscular junction

4. Sarcomeres

Q. what is neuro muscular junction?

Q. Can we write the formula of pyruvate like C₃H₃O₃^- and not CH₃COCOO^- ?

Q.

Which of the following is not correct?

1. Acetylcholine binds to the receptor channels at the motor end of the plate of the muscles

2. Neuromuscular junction is between the motor nerve and skeletal muscle.

3. Acetylcholine is the Neurotransmitter

4. The calcium causes the release of acetylcholine