Automatic
Nervous System
Kayla Hobbs
476-479

2 ANS division
Sympathetic Divison
The left side of the image is the distribution to the skin.
The right side is innervation of visceral organs Parasympathetic Division

Every single nerve has a gray ramus that carries sympathetic postganglionic fibers for distribution in the body walls and limbs.
In the head and neck postganglionic sympathetic fibers leaving the superior cervical supply to regions innervated by the cranial nerves.
Sympathetic nerves are bundles of postganglionic fibers in the thoracic cavity (heart and lungs).

Parasympathetic
The Vagus Nerve X alone provides around
75% of all parasympathetic outflow.
The preganglionic fibers sacral segment of the spinal cord carry the sacral parasympathetic. These fibers don’t join the ventral roots of the spinal nerves. Instead the preganglionic fibers form distinct pelvic nerves. The preganglionic innervate the intramural ganglia in the walls of the kidney, urinary bladder, some of the large intestine and sex organs

Effects of the
Sympathetic and
Parasympathetic
Neurotransmitter release in the sympathetic divison
The effects of sympathetic stimulation result from interaction of the norepinephrine(NE) and epinephrine(E) with adrenergic receptors in the plasma membrane

2 types of
Adrenergic
receptors
Alpha Receptors;
• NE stimulates the alpha receptors to a faster degree than beta receptors thoughout the body.
• E stimulates the Alpha receptors throughout the body.
• The alpha’s located near the sympathetic terminals are affected by the NE that is released from adrenal medulla. Adrenergic receptors(continu ed)

Beta Receptors:

• Sympathetic activation and release of E and NE are released by the adrenal medulla and affects alpha and beta receptors through the whole body.
• Tissue concentration of E and NE released by the adrenal medullae remain elevated for as long as
30 seconds, and the metabolic effects might last for several minutes.

• The effects of Beta are predominate because the adrenal medulla release 3 times as much as E than
NE does during sympathetic activation

Neurotransmitter released into the sympathetic division of the
Alpha receptors
Norepinephrine goes into the alpha receptor.
2 options: Alpha 1 or alpha 2 receptor
• Alpha 1:
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•
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Second messengers are activated
Release Ca++ from the endoplasm reticulum.
Either smooth muscle contracts or gland cell secrete. • Alpha 2
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Reduction of cAMP levels
Inhibition of cell

Neurotransmitter released into the sympathetic division of the Beta