BIOL-65 ch16

Sympathetic Division

• Flight or fight (Physical activity)
• Increase heart rate and blood glucose
• Reduce blood flow to Skin and GI Tract

Parasympathetic Division

• Rest and Digest (calm)
• Decrease heart rate
• Stimulate digestion and waste elimination

Autonomic Tone

Balance between activity of sympathetic and parasympathetic
(Resting heart rate)

What are the 2 neural pathways?

Preganglionic / Postganglionic neuron

Preganglionic Fiber / Neuron

• Neurosoma in brainstem or spinal cord
• Axons terminates in ganglion

Postganglionic Fiber

• Neurosoma in ganglion
• Axon extends to target

What is the anatomy of the Sympathetic Division?

• Called the Thoracolumbar division
• SHORT Preganglionic fibers and LONG Postganglionic fibers
• Sympathetic chain ganglia from cervical to coccygeal levels

What is the anatomy of the parasympathetic division?

• Called the Craniosacral division
• LONG preganglionic fibers and SHORT postganglionic fibers
• Terminal ganglia are in or near the target organ

Enteric Nervous System (ENS)

• Nervous system of the digestive tract
• Innervates smooth muscle and glands
• Regulates (motility of esophagus, stomach, and intestines; secretion of digestive enzymes and acid)

(Not autonomic, but we study it anyways)

Horner Syndrome

Unilateral pupillary constriction, sagging of eyelid, and flushing of skin due to lesion in sympathetic division

Raynaud Disease

Paleness, cyanosis, and pain in digits when cold or stressed due to excessive vasoconstriction

• Common in young women