Autonomic Nervous System

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The Autonomic Nervous System

Questions

178. A 58-year-old woman is suffering from hypertension, and the drugs presently available to her seem to be of little help. Recently, a new drug was approved for distribution and the patient’s physician recommended that she try it. The specific feature of this drug is that it selectively blocks synaptic transmission in autonomic ganglia in order to control blood pressure. Which of the following best characterizes this drug?

a. Cholinergic antagonist

b. Noradrenergic antagonist

c. Serotonergic antagonist

d. γ-Aminobutyric acid (GABA) ergic antagonist

e. Peptidergic antagonist

179. A patient with elevated heart rate and blood pressure is examined by a battery of physicians, and they conclude that his condition is due to a deficiency or loss of the carotid sinus reflex. Which of the following is a component of this reflex?

a. Baroreceptor afferent fibers from cranial nerve XI

b. Glossopharyngeal efferent fibers

c. Interneurons within the nucleus ambiguus of the medulla

d. Efferent fibers contained in the intermediate component of the facial nerve

e. Vagal efferent fibers

180. A patient has a tendency to have elevated blood pressure and heart rate, which can be controlled in part by a calcium channel blocker. Which of the following statements most accurately characterizes the effects of neurotransmitters upon calcium currents in heart muscle cells?

a. They are reduced by norepinephrine acting through β-receptors.

b. They are increased by norepinephrine acting through β-receptors.

c. They are increased by acetylcholine (ACh) acting on muscarinic receptors.

d. They are increased by ACh acting on nicotinic receptors.

e. They are increased by serotonin acting on serotonin 1A receptors.

181. A 78-year-old man presents with loss of voluntary control of bladder functions. Which of the following conditions most likely accounts for the loss of bladder functions?

a. Loss of vagal and sacral efferent fibers only

b. Loss of vagal, sacral, and descending fibers from the cerebral cortex

c. Loss of lumbar and sacral efferent fibers only

d. Loss of lumbar, sacral, and descending fibers from the cerebral cortex

e. Loss of upper thoracic and cervical fibers only

182. After a diagnosis of elevated blood pressure, an attempt is made to control blood pressure by preventing the synthesis and storage of norepinephrine. Which of the following should be applied to achieve this result?

a. Guanethidine sulfate

b. Reserpine

c. Phenoxybenzamine hydrochloride

d. Hexamethonium chloride

e. Metoprolol

183. A patient is diagnosed with a hypothalamic tumor that results in significant alteration of autonomic functions, including loss of regulation of blood pressure and heart rate. Such effects upon autonomic functions can be understood in terms of the functional connections of the hypothalamus with a brainstem or spinal cord structure. Which of the following structures normally receives such inputs?

a. Ventrolateral nucleus of the thalamus

b. Nucleus accumbens

c. Solitary nucleus

d. Red nucleus

e. Ventral horn cells at the level of C8 to T12 of the spinal cord

184. A 68-year-old man experiences syncope after standing for a while. After a short period, he is able to get up and appears to be alert. His brief fainting spell could best be accounted for in terms of which of the following?

a. Decreased vagal activity

b. Increased excitation of neurons in the thoracic intermediolateral cell column

c. Carotid sinus hypersensitivity

d. An increase in blood pressure

e. A lesion of the facial nerve

185. A patient is brought into the emergency room of a local hospital after he experiences orthostatic hypotension following a rapid response to a postural change. Magnetic resonance imaging (MRI) suggests that this change in blood pressure was caused by a tumor. At which of the following locations could a tumor most likely account for such a deficit?

a. Lateral thalamus

b. Premotor cortex

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