Understanding Clonus And Tetanus: Reflexes And Muscle Contractions

Understanding Clonus And Tetanus: Reflexes And Muscle Contractions

Question 1. Name the drug that stimulates neuromuscular junction.
Answer:

• Neostigmine.
• Physostigmine
• Di-isopropyl fluorophosphates.

Question 2. Properties of cardiac muscle.
Answer:

1. Electrical properties:

1. excitability:
   • Cardiac muscle forms a wave of depolarization in response to a stimulus.
2. Autorhythmicity:
   • The heart continues to beat for quite some time even after all nerves to it are cut due to pacemaker.
3. Conductivity:
   • Cardiac muscle spreads the impulses from SA nodes to all other parts of the heart.

2. Mechanical properties:

1. Contractility:
   • It is ability of the tissue to shorten in length after receiving a stimulus.
2. All or none law:
   • When a stimulus is applied, whatever may be the strength, the whole cardiac muscle responds to the maximum or it does not give response at all.
3. Refractory period:
   • It is the period in which the muscle does not show any response to a stimulus.

Question 3. What is clonus and tetanus?
Answer:

Clonus:

• It is a series of rapid and repeated involuntary jerky movements which occurs while eliciting deep reflexes
• Clonus occurs in individuals with upper motor neuron lesions due to hypertonicity of muscles and exaggeration of deep reflexes

Tetanus:

• It is sustained contraction of muscle due to repeated stimuli with high frequency
• The muscle relaxes only after the stoppage of stimuli or when the muscle is fatigued
• If frequency of stimuli is less, partial fusion of contraction occurs leading to incomplete tetanus