Autonomic Nerveous system

Question 1

Describe the general structure of the autonomic portion of the nervous system

Answer 1

It is part of the peripheral nervous system, generally involving a preganglionic neuron & a postganglionic neuron. The preganglionic for SNS exits the spinal cord in the T1-L2 region. The preganglionic for the PNS exits the spinal cord in the S2-S4 region plus the brain stem along with cranial nerves III, VII, IX and X. They postganglionic neurons innervate visceral structures such as smooth muscle, cardiac muscle and glands.

Question 2

Name the 2 divisions of the ANS

Answer 2

1. Sympathetic
2. Parasympathetic

Question 3

What are the neurotransmitters of the ANS

Answer 3

1. Acetylcholine

Parasympathetic Pre and Post ganglionic fibers (ALL!)

Sympathetic post gangionic fibers

2. Norepinephrine

Sypathtic post gangionic fibers

Question 4

Explain the role of the hypothalamus and its relationship to the sympathetic and parasympathetic divisions

Answer 4

Hypothalamus is the control center for Autonomic Nervous System.

Question 5

Compare and contrast Parasympathetic and sympathetic stimulation

Answer 5

Heart: PNS decreases rate & strength of contraction, SNS is opposite

Lungs: PNS decreases size of airways & SNS is opposite

Digestion: PNS increases movement & secretions in all of digestion & SNS is opposite

Pupil: PNS constricts pupil, SNS dilates pupil.

Sweat glands: Only innervated by SNS and it causes you to sweat

Adrenal medulla: Only innervated by preganglionic neurons in SNS and it causes the adrenal medulla to release epinephrine & norepinephrine to exaggerate the fight or flight response.

Cutaneous & abdominal blood vessels: Only innervated by SNS and it causes them to constrict to decrease blood flow.

Skeletal muscle blood vessels: Only innervated by SNS and it causes them to dilate to increase blood flow.