Chapter 17 - end of chapter review questions

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

b

Postganglionic fibers of autonomic neurons are usually myelinated. unmyelinated. larger than preganglionic fibers. located in the spinal cord.

b

Sympathetic preganglionic fibers are characterized as being short in length and unmyelinated. short in length and myelinated. long in length and myelinated. long in length and unmyelinated.

b

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.

Kassie is stung on the neck by a wasp. Because she is allergic to wasp venom, her throat begins to swell and her respiratory passages constrict. Which would be more helpful in relieving her symptoms: acetylcholine or epinephrine? Why?

Kassie should be treated with epinephrine. This would mimic sympathetic activation, which dilates air passageways in the lungs. The constriction of her respiratory passages would be alleviated.

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. The 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 emergency in "fight-or-flight." The parasympathetic division promotes relaxation, nutrient uptake, energy storage, and "rest-and-digest."

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.

Describe the general organization of the pathway for visceral motor output.

Visceral motor neurons, called preganglionic neurons, send their axons, called preganglionic fibers, from the CNS to synapse on ganglionic neurons, whose cell bodies are located in ganglia outside the CNS.

What anatomical mechanism is involved in causing a person to blush? Blood flow to the skin is increased by parasympathetic stimulation. Sympathetic stimulation relaxes vessel walls, increasing blood flow to the skin. Parasympathetic stimulation decreases skin muscle tone, allowing blood to pool at the surface. 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 ______________. norepinephrine; inhibitory norepinephrine; excitatory acetylcholine; excitatory acetylcholine; inhibitory

c

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

c

11. 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

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

d

If the visceral signal from the small intestine does not reach the spinal cord, which structures might be damaged? preganglionic neurons white rami communicantes gray rami communicantes none of the above

d

Preganglionic fibers of the ANS sympathetic division originate in the cerebral cortex of the brain. medulla oblongata. brainstem and sacral spinal cord. thoracic and lumbar spinal segments.

d

The neurotransmitter at all synapses and neuroeffector junctions in the parasympathetic division of the ANS is epinephrine. cyclic AMP. norepinephrine. acetylcholine.

d

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

d

Damage to the ventral roots of the first five thoracic spinal nerves on the right side of the body would interfere with the ability to dilate the right pupil. dilate the left pupil. contract the right biceps brachii. contract the left biceps brachii.

a

Which of the following ganglia belong to the sympathetic division of the ANS? otic ganglion sphenopalatine ganglion sympathetic chain ganglia all of the above

c