A&P Final (Autonomic Nervous System)

The division of the autonomic nervous system that prepares the body for activity and stress is the _________ division. A) Sympathetic B) parasympathetic C) craniosacral D) intramural E) somatomotor

A) Sympathetic

Which of the following is true? A) drugs that block the action of acetylcholine esterase at synapses between postganglionic axons and effectors would act like parasympathomimetic drugs. B) Drugs that block the action of acetylcholine esterase at synapses between postganglionic axons and effetors would be parasympathetic blocking drugs. C) Both A and B are true. D) Neither A nor B are true.

A) drugs that block the action of acetylcholine esterase at synapses between postganglionic axons and effectors would act like parasympathomimetic drugs.

Dual innervation refers to situations in which: A) vital organs receive instructions from both sympathetic and parasympathetic fibers B) the atria and ventricles of the heart recieve autonomic stimulation from the same nerves C) sympathetic and parasympathetic fibers have similar effects D) a, b, and c are correct

A) vital organs receive instructions from both sympathetic and parasympathetic fibers

What neurotransmitter is released by all parasympathetic neurons?

ACh

Under which of the following circumstances would the diameter of peripheral blood vessels be greatest? A) increased sympathetic stimulation B) decreased sympathetic stimulation C) increased parasympathetic stimulation D) decreased parasympathetic stimulation E) both increased parasympathetic and sympathetic stimulation

B) decreased sympathetic stimulation

Effects produced by the parasympathetic branch of the autonomic nervous system include: A) dilation of the pupils B) increased secretion by digestive glands C) dilation of respiratory passages D) increased heart rate E) increased breakdown of glycogen by the liver

B) increased secretion by digestive glands

How would a drug that stimulates acetylcholine receptors affect the sympathetic nervous system?

Because preganglionic fibers of the sympathetic nervous system release acetylcholine (ACh), a drug that stimulates ACh receptors would stimulate the postganglionic fibers of sympathetic nerves, resulting in increased sympathetic activity.

An individual with high blood pressure is given a medication that blocks beta receptors. How could this medication help correct that person's condition?

Blocking the beta receptors on cells would decrease or prevent sympathetic stimulation of tissues containing those cells. Heart rate, force of contraction of cardiac muscle, and contraction of smooth muscle in the walls of blood vessels would decrease, lowering blood pressure.

Which receptor does epinephrine stimulate?

Both alpha and beta receptors

short reflexes

Bypass the CNS entirely. Involve sensory neurons and interneurons whose cell bodies lie in autonomic ganglia. Control very simple motor responses with localized effects. In general, short reflexes may control patterns of activity iin one small part of a target organ.

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) acetylcholine, inhibitory

During sympathetic stimulation, a person may begin to feel "on edge"; this is the result of: A) increased energy metabolism by muscle tissue B) increased cardiovascular activity C) stimulation of the reticular activating system D) temporary insensitivity to painful stimuli E) decreased levels of epinephrine in the blood

C) stimulation of the recticular activating system

Nicotine stimulates cholinergic receptors of the ANS. Based on this information, how would cigarette smoking affect eh cardiovascular system?

Cholinergic receptors are found in all the ganglia of the ANS, so nicotine would stimulate both sympathetic and parasympathetic responses in cardiovascular tissues. Although increased sympathetic stimulation increases heart rate and force of contraction, increased parasympathetic stimulation simultaneously decreases blood flow to the heart muscle. In addition to elevating heart rate and force of contraction, sympathetic stimulation also constricts peripheral blood vessels, all of which contribute to increased blood pressure.

The neurotransmitter at all synapses and neuromuscular or neuroglandular junctions in the parasympathetic division of the ANS is; A) epinephrine B) norepinephrine C) cyclic-AMP D) acetylcholine

D) acetylcholine

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 digestive system B) diarrhea C) profuse urination D) increased blood pressure E) decreased heart rate

D) increased blood pressure

The autonomic division of the nervous system directs: A) voluntary motor activity B) Conscious control of skeletal muscles C) unconscious control of skeletal muscles D) processes that maintain homeostasis E) sensory input from the skin

D) processes that maintain homeostasis

You are home alone at night when you hear what sounds like breaking glass. What physiological effects would this experience probably produce, and what would be their cause?

Due to the stimulation of the sympathetic division, you would experience increased respiratory rate, increased peripheral vasoconstriciton and elevation of blood pressure, increased heart rate and force of contraction, and an increased rate of glucose release into the bloodstream

Phil is stung on his cheek by a wasp. Because Phil is allergic to wasp venom, his throat begins to swell and his respiratory passages constrict. Would acetylcholine or epinephrine be more helpful in relieving his condition. Why?

Epinephrine would be more effective, because it would reduce inflammation and relax the smooth muscle of the airways, making it easier for Phil to breathe.

Why is autonomic tone a significant part of ANS function?

If autonomic motor neurons maintain a background level of activity at all times, they can either increase or decrease their activity, providing a greater range of control options

Under which set of circumstances would heart rate be the fastest?

Increased sympathetic and decreased parasympathetic stimulation

How would the stimulation of muscarinic receptors in cardiac muscle affect the heart?

It would cause K+ channels to open, resulting in hyperpolarization of cardiac plasma membranes and a decreased heart rate

While out for a walk, Julie suddenly meets an angry dog. Which division of the autonomic nervous system is responsible for the physiological changes that occur in Julie as she turns and runs?

Sympathetic

While studying the activity of smooth muscle in blood vessels, Shelly discovers that, when applied to a muscle plasma membrane, a molecule 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?

The molecule is probably mimicking NE and binding to alpha-1 receptors

Why does sympathetic function remain intact even when the ventral roots of the cervical spinal nerves are damaged?

The preganglionic fibers innervating the cervical ganglia originate in the ventral roots of the thoracic segments, which are undamaged

On the basis of anatomy, how could you distinguish the sympathetic division form the parasympathetic division of the ANS?

The sympathetic division of the ANS includes preganglionic fibers from the lumbar and thoracic regions of the spinal cord, whereas the parasympathetic division includes preganglionic fibers from the cranial and sacral regions.

How many motor neurons are needed to carry an action potential from the spinal cord to smooth muscles in the wall of the intestine?

Two neurons are needed to carry an action potential from the spinal cord to smooth muscles in the intestine. The first neuron carries the action potential from the spinal cord to the autonomic ganglion, and a second neuron carries the action potential from the autonomic ganglion to the smooth muscle

What are the components of a visceral reflex arc?

Visceral reflex arcs include a receptor, a sensory neuron, an interneuron (may or may not be present), and two visceral motor neurons.

long reflexes

Visceral sensory neurons deliver information to the CNS. Long reflexes typically coordinate the activities of an entire organ.

Luke has a brain tumor that is interfering with the function of his hypothalamus. Expalin why this tumor would interfere with autonomic function.

a brain tumor that interferes with hypothalamic function would also interfere with autonomic function, because centers in the hypothalamus are involved with autonomic (visceral) function.

autonomic tone

a resting level of spontaneous activity for ANS. Significant for where dual intervation occurs

define visceral reflex

a visceral reflex is an autonomic reflex initiated in the viscera. It is an automatic motor response that can be modified, facilitated, or inhibited by higher centers, especially those of the hypothalamus.

Which receptor does norepinephrine stimulate?

alpha receptors to a greater degree than beta receptors

Why is the parasympathetic division sometimes referred to as the anabolic system?

because parasympathetic stimulation leads to a general increase in the nutrient content of the blood. Cells throughout the body respond to the increase by absorbing the nutrients and using them to support growth and other anabolic activities.

Alpha-2 receptors

lowers cyclic-AMP levels in cytoplasm. cAMP is an important messenger that can activate or inactivate key enzymes. Inhibitory effect. When sypathetic division is active, the NE released binds to a2 receptors at paraympathetic neuromuscular and neuroglandular junction and inhibits their activity.

Alpha-1 receptors

more common. Its stimulation results in G-protein activation and releases calcium ions into cytosol. Excitatory effect.

what effect would the loss of sympathetic tone have on blood flow to a tissue?

most blood vessels receive sympathetic stimulation, so a loss of sympathetic tone would relax the smooth muscles lining the tissue.

Name the two types of cholinergic receptors on the postsynaptic membranes of parasympathetic neurons.

nicotinic receptors and muscarinic receptors

B2 receptors

stimulation causes inhibition, triggering relaxation of smooth muscles along respiratory tract. Makes breathing easier

B1 receptors

stimulation leads to increase in metabolic activity. Example, stimulation in heart increases heart rate.

B3 receptors

stimulation leads to lipolysis, the breakdown of triglycerides stored within adipocytes.

identify the two major divisions of the autonomic nervous system.

the parasympathetic and sympathetic

Which nerve is responsible for the parasympathetic innervation of the lungs, heart, stomach, liver, pancreas, and parts of the small and large intestines?

the vagus nerve

dual intervation

when an organ receives instructions from both parasympathetic and sympathetic nervous systems