Page 57 - Physiology and Pathophysiology MNU 2024-2025 نظرى

Clinical pharmacy 2024/2025 Level 2 Pharm D Physiology and Pathophysiology (MD303)
2. Spinal Cord

Role of Spinal Cord

1. Nervous tissue link between the brain and the rest of body (except cranial nerve)

2. Some activities of spinal cord are independent or brain & controlled at level of spinal cord ex :

spinal reflexes & To perform this function ,it Has 2 Tracks :
A) Sensory nerve tracts (from visceral organ)=afferent

1- The skin. 2- The tendons, muscles and joints.
✓ Sensory receptors (nerve  Sensory receptors are nerve endings in these

endings) in the skin called structures called proprioceptors and they are

cutaneous receptors➔ stimulated by stretching.

stimulated by pain, heat,  Together with impulses from the eyes and the ears ➔

cold and touch including they are associated with the maintenance of balance
pressure. and posture and with perception of the position of

✓ Nerve impulses generated the body in space.

are conducted by three  These nerve impulses have two destinations.

neurons to the sensory area in 1) By a three-neuron system the impulses reach the sensory

the opposite hemisphere of area of the opposite hemisphere of the cerebrum.
the cerebrum where the 2) By a two-neuron system the nerve impulses reach the

sensation and its location cerebrum hemisphere on the same side

are perceived.

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