Autonomic Nervous System

External sphincter muscles

________ are voluntarily controlled (by somatic nervous system)

Autonomic Nervous System

the system for involuntary subconscious functions

Autonomic ganglia

the site of physiological contact between pre and post synaptic fibers

pre-ganglionic neurotransmitter

Acetylcholine

pre-ganglionic receptor

Nicotinic receptors

Neurotransmitters of Sympathetic System

mainly norepinephrine (NE)

Receptors of Sympathetic System

α & β receptors

Post-ganglionic Neurotransmitters of Parasympathetic System

Acetylcholine

Post-ganglionic Receptors of Parasympathetic System

muscarinic receptors

Sympathetic System

Thoraco-lumbar (T1-T12, L1, L2, L3)

Parasympathetic System

Cranio-sacral (III-VII, IX, X S2, S3, S4)

Parasympathetic System degree of diversion

1:9 (localized response)

Sympathetic System degree of diversion

1:32 (wide spread)

Types of Autonomic Ganglia

1. Lateral/ paravertebral
2. Terminal
3. Collateral

Lateral/ paravertebral locations of Autonomic Ganglia

* close to spinal cord
* sympathetic
* 3 cervical
* 12 thoracic
* 4 lumbar
* 4 sacral

Terminal Autonomic Ganglia locations

* at the wall of the organ with no or very short post-ganglionic fibers
* parasympathetic

Collateral Autonomic Ganglia

* around the major branches of the abdominal aorta
* symapathatic

Parasympathetic System action (in relation to defecation and micturition)

Defecation and micturition

Contraction of rectal muscles

Relaxation of internal sphincter muscles

Sympathetic System action (in relation to defecation and micturition)

No defecation or micturition

Relaxation of rectal muscles

Contraction of internal sphincter muscles

Relationship between sympathetic and parasympathetic system

Reciprocal and complementary