C14 1-3

Question 1

1. Define autonomic nervous system (ANS) and explain its relationship to the peripheral nervous system.

Answer 1

ANS: Self-governing, efferent division of the PNS that innervates cardiac and smooth muscles, glands and adipose tissue; aka involuntary or visceral motor system. It is a division of the PNS that targets motor response to viscera.

Question 2

Wht does the two-neuron motor pathway of the ANS allow for?

Answer 2

Increasing communication and control via neuronal convergence and neuronal divergence.

Question 3

Somatic vs. Autonomic, effectors

Answer 3

Somatic: Skeletal muscle

Autonomic: Smooth and cardiac muscle, glands, adipose

Question 4

Somatic vs. Autonomic, efferent pathways

Answer 4

Somatic: Single neuron from CNS to effector organ.

Autonomic: Two neuron chain from CNS to effector organ (preganglionic to postganglionic)

Question 5

Somatic vs. Autonomic, neurotransmitters released

Answer 5

Somatic: Ach

Autonomic:

SYMPATHETIC Ach/preganglionic –> NE/postganglionic OR Ach/pre –> Adrenal Medulla –> NE hormone in blood vessel

PARASYMPATHETIC Ach/pre –> Ach/post

Question 6

Somatic vs. Autonomic, myelination

Answer 6

Somatic: Heavily myelinated

Autonomic: Lightly myelinated/preganglionic, Unmyelinated/postganglionic

Question 7

Somatic vs. Autonomic, effect

Answer 7

Somatic: Stimulatory

Autonomic: Stimulatory or inhibitory, depending on neurotransmitter and type of receptor on effector organ.

Question 8

Somatic vs. Autonomic, ganglia

Answer 8

Somatic: Cell bodies in the CNS, axons extend into spinal or cranial nerves all the way to the skeletal muscle they activate.

Autonomic: Cell body of the first preganglionic neuron resides in brain or spinal cord, the cell body of the second postganglionic neuron is in an autonomic ganglion outside the CNS. Its postganglionic axon extends to the effector organ.

Question 9

3. Compare and contrast the functions of the parasympathetic and sympathetic divisions.

Answer 9

Sympathetic: Prepares the body for activity, fight or flight. E division

Parasympathetic: Digestion, elimination, glands, rest and digest. (SLUDD - salivation/lacrimation/urination/defacation/digestion)

Question 10

Neuronal convergence

Answer 10

Axons from numerous preganglionic neurons synapse with and influence a single ganglionic neuron

Question 11

Neuronal divergence

Answer 11

Axons from one preganglionic neuron synapse with and influence numerous ganglionic neurons