Question

describe in detail the physiological functions of spinal cord

Answer 1

• Spinal cord is a long narrow cylindrical structure.
• It lies outside the skull beginning from its base at the foramen magnum to terminate at the lower border 1st lumbar vertebrar.
• Below the 1st lumbar vertebrae the spinal cord contains the lumbar and sacral roots in band known as Cauda equina.

Functions of the spinal cord can be divided into sensory, motor  and autonomic functions.

A. SENSORY FUNCTIONS

• All the sensations after entering the spinal cord in dorsal nerve root are conveyed to the brain (postcentral gyrus) by ascending either in the

1. in the Dorsal column of the same side which conveys fine touch, tactile localization and discrimination, pressure, proprioception and kinesthetic sensation ie sensation of body position in space and joint movement and vibration sense, or

2. In the Spinothalamic tracts of the opposite side:

anterior (ventral) tract conveys gross (crude) touch and tactile localization whereas lateral tract conveys pain and temperature sensations.

B. MOTOR FUNCTIONS

The spinal cord controls:

1. The tone and power of the muscles .
2. The movements of muscles and joints.
3. The deep (tendon) reflexes .
4. The superficial reflexes.

C. AUTONOMIC FUNCTIONS

The spinal cord regulates:

1. The body temperature.

2. The visceral functions

• It regulates the activity of smooth muscle, heart, glands of the GIT, sweat gland, adrenals etc.
• The main aim of the autonomic function is to maintain the optimal internal environment of the body.