Chapter 17- Review Questions

How do sympathetic chain ganglia differ from both collateral ganglia and intramural ganglia?

-Sympathetic chain ganglia are innervated by preganglionic fibers from the thoracolumbar regions of the spinal cord, and they are interconnected by preganglionic fibers and axons from each ganglion in the chain innervating a particular body segment. -Collateral ganglia are part of the abdominal autonomic plexus anterior to the vertebral column. Preganglionic sympathetic fibers innervate the collateral ganglia as splanchnic nerves. -Intramural ganglia are part of the parasympathetic division. They are located near or within the tissues of the visceral organs.

Why are the effects of parasympathetic stimulation more specific and localized than those of the sympathetic division?

-The parasympathetic division innervates only visceral structures served by some cranial nerves or lying within the thoracic and/or abdominopelvic cavities. -The sympathetic division has widespread impact due to extensive collateral branching of preganglionic fibers, which reach visceral organs and tissues throughout the body.

Compare the general effects of the sympathetic and parasympathetic divisions of the ANS.

-The sympathetic division of the ANS stimulates metabolism, increases alertness, and prepares for an emergency in "fight-or-flight." -The parasympathetic division promotes relaxation, nutrient uptake, energy storage, and "rest-and-digest."

Epinephrine

Adrenal medulla

Acetylcholine

All preganglionic fibers

Prevertebral

Collateral ganglia

In some severe cases, a person suffering from stomach ulcers may need to have surgery to cut the branches of the vagus nerve that innervates the stomach. How would this help the problem?

Cutting off autonomic nervous system stimulation to the stomach through the vagus nerve decreases stimulation of digestive glands, thus reducing their secretion. This may diminish ulcers in the wall of the stomach.

Preganglionic

First neuron

Sympathetic

Long postganglionic fiber

Splanchnic

Preganglionic fibers to collateral ganglia

Crisis

Sympathetic activation

Paravertebral

Sympathetic chain ganglia

Thoracolumbar

Sympathetic division

Parasympathetic

Terminal ganglia

The effects of epinephrine and norepinephrine released by the adrenal glands last longer than those of either chemical when released at neuroeffector junctions. Why?

There are NO enzymes to break down epinephrine and norepinephrine in the blood and very little in peripheral tissues.

Postganglionic fibers of autonomic neurons are usually a) myelinated b) unmyelinated c) larger than preganglionic fibers d) located in the spinal cord

b

Splanchnic nerves a) are formed by parasympathetic postganglionic fibers b) include preganglionic fibers that go to collateral ganglia c) control sympathetic function of structures in the head d) connect one chain ganglion with another

b

Sympathetic preganglionic fibers are characterized as being a) short in length and unmyelinated b) short in length and myelinated c) long in length and myelinated d) long in length and unmyelinated

b

What anatomical mechanism is involved in causing a person to blush? a) Blood flow to the skin is increased by parasympathetic stimulation b) Sympathetic stimulation relaxes vessel walls, increasing blood flow to the skin c) Parasympathetic stimulation decreases skin muscle tone, allowing blood to pool at the surface d) Sympathetic stimulation increases respiratory oxygen uptake, making the blood brighter red

b

All preganglionic autonomic fibers release at their axon terminals, and the effects are always a) norepinephrine; inhibitory b) norepinephrine; excitatory c) acetylcholine; excitatory d) acetylcholine; inhibitory

c

The large cells in the adrenal medulla, which resemble neurons in sympathetic ganglia, a) are located in the adrenal cortex b) release acetylcholine into blood capillaries c) release epinephrine and norepinephrine into blood capillaries d) have no endocrine functions

c

Which of the following ganglia belong to the sympathetic division of the ANS? a) otic ganglion b) sphenopalatine ganglion c) sympathetic chain ganglia d) all of the above

c

Cutting the ventral root of the spinal nerve at L2 would interrupt the transmission of what type of information? a) voluntary motor output b) ANS motor output c) sensory input d) a and b

d

Preganglionic fibers of the ANS sympathetic division originate in the a) cerebral cortex of the brain b) medulla oblongata c) brainstem and sacral spinal cord d) thoracic and lumbar spinal segments

d

The neurotransmitter at all synapses and neuroeffector junctions in the parasympathetic division of the ANS is a) epinephrine b) cyclic AMP c) norepinephrine d) acetylcholine

d

The white ramus communicans a) carries the postganglionic fibers to the effector organs b) arises from the dorsal root of the spinal nerves c) has fibers that do not diverge d) carries the preganglionic fibers into a nearby sympathetic chain ganglion

d

Visceral motor neurons in the CNS a) are ganglionic neurons b) are in the dorsal root ganglion c) have unmyelinated axons except in the lower thoracic region d) send axons to synapse on peripherally located ganglionic neurons

d