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Clinical pharmacy 2024/2025 Level 3 Pharm D Pharmacology 1 (PO 502)

Autonomic Nervous System

The nervous system is divided into:
1- Central nervous system (CNS). 2- Peripheral nervous system (PNS).

1- The Central nervous system (CNS):

Brain Spinal cord

subdivided into: divided into 31 segments in the
1. Cerebrum → consists of cerebral cortex following regions:

and subcortical centers (thalamus,  Cervical region (8 segments).
hypothalamus and basal ganglia).  Thoracic region (12 segments).
2. Brain stem → (Mid brain, pons and  Lumbar region (5 segments).

medulla oblongata).  Sacral region (5 segments).
3. Cerebellum.  Coccygeal region (1 segment).

2- Peripheral nervous system:

Somatic N.S. innervate voluntary or skeletal muscle (motor function)
innervate involuntary functions (smooth muscles, cardiac muscle,
blood vessels and glands)
Autonomic Consists of two divisions:
N. S.
➢ Sympathetic (Thoracolumbar) nervous system.
➢ Parasympathetic (Craniosacral) nervous system.

Sympathetic N. S Parasympathetic N.S.
cells that give rise to the pre-ganglionic 3rd (Oculomotor), seventh (facial), ninth

fiber lie in spinal cord from eighth (glossopharyngeal) and tenth cranial
cervical to the third lumber segment. nerve (vagus) and the first three sacral
nerves.
➢ These two systems communicate by releasing chemical mediators or

neurotransmitters.
➢ The neurotransmitter released at all ganglia is Ach.

✓ The neurotransmitter released at the
post-ganglionic sympathetic nerve
ending → NE except to ✓ The neurotransmitter released at the

1. Sweat gland → post-ganglionic Nerve post-ganglionic parasympathetic nerve
release Ach ending (smooth muscles, cardiac
2. adrenal medulla → Preganglionic muscle and gland) is Ach.

release Ach act on N receptor ➔
release E

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