Page 601 - Fundamentals of anatomy physiology
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588 Unit 3 Control and Regulation 25. A possible side effect of a drug used to open the airways of someone
suffering from an asthma attack is (a) decreased activity of the diges-
LEVEL 2 Reviewing Concepts tive system, (b) diarrhea, (c) profuse urination, (d) increased blood
20. Dual innervation refers to situations in which (a) vital organs receive pressure, (e) decreased heart rate.
instructions from both sympathetic and parasympathetic fibers, 26. List some key physiological effects which occur during sympathetic
(b) the atria and ventricles of the heart receive autonomic stimulation activation (the “fight or flight” reaction).
from the same nerves, (c) sympathetic and parasympathetic fibers
have similar effects, (d) a, b, and c are correct. 27. Why is autonomic tone a significant part of ANS function?
21. Damage to the hippocampus, a component of the limbic system, 28. Nicotine stimulates cholinergic receptors of the ANS. Based on this
leads to (a) a loss of emotion due to forgetfulness, (b) a loss of
consciousness, (c) a loss of long-term memory, (d) an immediate information, how would cigarette smoking affect the cardiovascular
loss of short-term memory. system?
22. Why does sympathetic function remain intact even when the ventral 29. The sight of a tragic accident or very bad news can cause people to
roots of the cervical spinal nerves are damaged? faint. How does this happen?
23. During sympathetic stimulation, a person may begin to feel “on edge”;
this is the result of (a) increased energy metabolism by muscle tissue, LEVEL 3 Critical Thinking and Clinical Applications
(b) increased cardiovascular activity, (c) stimulation of the reticular
activating system, (d) temporary insensitivity to painful stimuli, 30. Phil is stung on his cheek by a wasp. Because Phil is allergic to wasp
(e) decreased levels of epinephrine in the blood. venom, his throat begins to swell and his respiratory passages con-
24. Under which of the following circumstances would the diameter strict. Would acetylcholine or epinephrine be more helpful in relieving
of peripheral blood vessels be greatest? (a) increased sympathetic his condition? Why?
stimulation, (b) decreased sympathetic stimulation, (c) increased
parasympathetic stimulation, (d) decreased parasympathetic 31. While studying the activity of smooth muscle in blood vessels, Shelly
stimulation,(e) both increased parasympathetic and sympathetic discovers that, when applied to a muscle plasma membrane, a mol-
stimulation. ecule chemically similar to a neurotransmitter triggers an increase in
intracellular calcium ions. Which neurotransmitter is the molecule
mimicking, and to which receptors is it binding?
Clinical Case Wrap-Up
The First Day in Anatomy Lab Tim’s rapid recovery begins as
soon as the sympathetic division of
Tim has suffered a vasovagal (vaso, vascular; vagal, the ANS takes over. Norepinephrine
vagus nerve) loss of consciousness, commonly is released at the cardiac plexus and
known as fainting. Environmental triggers, including the smell of throughout the body. His heart rate
the anatomy lab and the sight of the cadaver, caused a momen- and blood pressure increase, as does
tary malfunction of his autonomic nervous system (ANS). The his level of consciousness.
sympathetic division of the ANS, sometimes called the “fight or
flight” division, failed him. The parasympathetic division of the “Don’t worry, Tim,” says his instructor. “Everybody is allowed
ANS, sometimes called the “rest and digest” or “faint and freeze” one fainting episode. And everybody can overcome this. Next
division, went into overdrive. time just lie down before you fall down.”
Parasympathetic stimulation of the vagus nerve caused it
to release ACh at the cardiac plexus. Meanwhile, there was no 1. Why would the instructor tell Tim to lie down, or want him to
counteracting stimulation from the sympathetic nervous system. get his head below his heart, the next time he feels faint?
This caused Tim’s heart rate to slow, the force of contractions to
decrease, and his blood pressure to drop. As a result, blood flow 2. In addition to the cardiac plexus, where else in the body
to the brain decreased, causing the fainting episode. If the brain would the sympathetic nervous system act during Tim’s
does not get enough blood, it shuts down quickly. recovery?
See the blue Answers tab at the back of the book.
