A neural signal reaching this junction releases a neurotransmitter…………. Which generates an action potential in the ………..

1. Acetyl choline, Sarcolemma

2. Inositol, Sarcolemma

3. GABA, Sarcoplasmic reticulum

4. GABA, Sarcoplasm

Muscle Contraction is initiated by

1. A signal sent by CNS via a motor neuron

2. A signal sent by PNS via a motor neuron

3. A signal sent by ANS via efferent neuro

4. A signal sent by ANS via efferent neuron

Ca⁺² bind ________ in the skeletal muscles and leads to exposure of the binding site for ________ on the filament _______:

(1) Troponin, myosin, actin                

(2) Troponin, actin, relaxin

(3) Actin, myosin, troponin                

(4) Tropomysin, myosin, actin

Consider the following statements:

I. A motor neuron along with the muscle fibres connected to it constitute a motor unit

II. The neurotransmitter released at the neuro-muscular junction is Acetylcholine.

III. Myosin head has ATPase activity.

Which of the above statements are true?

1. I and II only

2. I and III only

3. II and III only

4. I, II, and III

Neuromuscular junction or motor endplate is

1. The junction between a motor neuron and the sarcolemma of the muscle fiber

2. The junction between a motor neuron and sensory neuron

3. The junction between the sensory neuron and the sarcolemma of the muscle fibre

4. Both 1 and 3

Put the following phrases in proper order to describe what occurs at the neuromuscular junction to trigger muscle contraction:

1. II, IV, I, VI, VII, III, V           

2. II, IV, VI, I, VII, III, V

3. I, II, III, IV, V, VI, VII             

4. VII, VI, V, IV, III, II, I

The ATPase activity of the myosin head is dependent on:

1. Magnesium ions

2. Manganese ions

3. Calcium ions

4. Ferric ions

The binding of troponin on actin Filaments actually unmasks the …..

1. Active site for Tropomyosin

2. Active site for ATP

3. Active site for Myosin

4. Active site for troponin

Which of the following statements is incorrect?

1. A new ATP binds and cross-bridge is broken with the next cycle of contraction

2. The process of contraction continues till the calcium ions are pumped back to the sarcoplasmic cisternae and resulting in the unmasking of actin Filaments

3. The reaction time of the fibres can vary in different muscles

4. Both 1 and 3

The combination of a neuron and the muscle fiber it associates with is called a/an.

1. fascicle

2. motor end plate

3. motor unit

4. myoneural junction