Page 24 - Physiology and Pathophysiology MNU 2024-2025 نظرى

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

Autonomic nervous system

Has two major divisions: the sympathetic and the parasympathetic, which often complement

each other in the regulation of organ system function.

Characteristics Sympathetic Division Parasympathetic Division

Origin of preganglionic Spinal cord segments T1-L3 Nuclei of CN III, VII, IX, and X; spinal cord

neurons (thoracolumbar) segments S2-S4 (craniosacral)

Location of autonomic Paravertebral and collateral Terminal ganglia: In or near effector organs
ganglia

Length of preganglionic Short Long

axons
Length of Long Short

postganglionic axons

Effector organs Smooth muscle; cardiac muscle; glands

Neurotransmitter and
Ach /nicotinic receptor.
receptor type in

ganglion

Neurotransmitter in Norepinephrine (except sweat ACh
effector organs glands)

Receptor types in α1, α2, β1, β2, β3 Muscarinic
effector organs

Activation Mass activation Not activated as whole

(Activation as a unit  Stimulation of separate Parasympathetic
affecting all of its effector nerve

organs at the same time)

Function Fight & Flight Rest & Digest [ Relaxing effect]

E ➔(exercise, excitement, D ➔ (Digestion, defecation & diuresis
emergencies) 1) ↓ heart rate

↑ Heart rate, ↑ blood glucose, 2) Dilates visceral blood vessels.

bronchodilation 3) ↑ digestive activity
& ↑ blood flow to skeletal

muscle)

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