Important Neurophysiology Questions: Synapse, Reflex, and Motor Neurons

Important Neurophysiology Questions: Synapse, Reflex, and Motor Neurons

Question 1. Synpatic transmission. (or) Trace the lateral spinothalamic tract
Answer:

Question 2. Define reflex and write about reflex activity.
Answer:

Reflex:

• It is an involuntary response to a stimulus which depends on integrity of reflex pathway.

Reflex activity:

• It is a type of protective mechanism.
• It protects the body from irreparable damages.

Examples:

1. When hand is placed one a hot object, it is withdrawn immediately.

2. When a very bright light is thrown into the eyes, eyelids are closed and pupils are constricted.

• This prevents damage to retina.

Question 3. Lower motor neuron.
Answer:

• Lower motor neuron are the anterior grey horn cells in the spinal cord and the motor neurons of the cranial nerve nuclei situated in brainstem.
• They innervate the muscles directly.
• They constitute the final common pathway of motor system.
• Its action is under the influence of the upper motor neurons.

Lower motor neuron Types:

1. Alpha motor neuron.

• Innervates extrafusal fibers of muscles and causes contraction of muscles.

2. Gamma motor neuron.

• Innervates intrafusal fibers of muscles and maintains the muscle tone.