A&P CH 14

Which of the following parasympathetic nerves control the production of tears and nasal secretions?

Facial nerve (CN VII)

Damage to sacral nerves is most likely to affect which of the following targets?

Urinary bladder and the last portion of the large intestine

Which of the following is not a result of the activation of the sympathetic nervous system?

Vasodilation to the digestive organs The parasympathetic nervous system is involved in the "rest and digest" response, so the blood vessels to the digestive organs vasodilate to accommodate this increase in function. Return to Assignment

Which of the following neurotransmitters is responsible for stimulation of skeletal muscle and in the ANS?

acetylcholine Acetylcholine is used as the neurotransmitter at the neuromuscular junctions, but it is also a neurotransmitter in the ANS.

Receptors that bind norepinephrine and epinephrine are known as __________.

adrenergic

Nicotine is a drug that stimulates nicotinic receptors. It will have an effect __________.

at all autonomic ganglia Nicotinic cholinergic receptors are at both sympathetic and parasympathetic ganglia.

The body system that oversees vital functions, such as heart rate, blood pressure, and digestive processes, is the:

autonomic nervous system.

A patient expresses feeling dizzy when standing, nauseated when eating, and having difficulty with emptying their bladder. You want to run some tests to determine if they are suffering from:

autonomic neuropathy. Submit An individual with autonomic neuropathy would have difficulty maintaining homeostasis of many vital functions, including blood pressure, digestion, and urine production. Early symptoms include dizziness and fainting when standing; vomiting and feeling nauseated while eating; and disturbances with bowel movements, bladder control, and sexual functioning.

A drug that inhibits the release of norepinephrine is likely to have the greatest effect on __________.

autonomic target cells

Sympathetic preganglionic neurons may synapse with postganglionic neurons via all of the following pathways except:

axon synapses in terminal ganglia in the walls of the organs being innervated.

An example of an organ under predominantly sympathetic tone is __________.

blood vessels Blood vessels are not dually innervated, so they are only under sympathetic tone.

Which of the following would not be a physiological variable under the control of the reticular formation?

body temperature The hypothalamus is primarily responsible for the regulation of body temperature.

Nicotinic and muscarinic receptors are classified as __________ receptors.

cholinergic

Receptors that bind acetylcholine are known as __________.

cholinergic

Parasympathetic neurons associated with the oculomotor nerve (CN III) synapse with ___________ ganglia before continuing on to their effector.

ciliary

Compared to parasympathetic ganglia, sympathetic ganglia are __________.

closer to the spinal cord Axons of sympathetic preganglionic neurons are short, so sympathetic ganglia are generally located close to the spinal cord.

Which of the following is NOT one of the roles of the parasympathetic nervous system?

controls the diameter of blood vessels Blood vessels are only innervated by the sympathetic division of the ANS.

Preganglionic neurons of the parasympathetic nervous system have __________ origin.

craniosacral The cell bodies of the preganglionic parasympathetic neurons are located within the nuclei of several cranial nerves in the brainstem, and in the sacral region of the spinal cord.

Most organs are innervated by neurons from both the sympathetic and parasympathetic nervous systems, a phenomenon referred to as __________.

dual innervation

The ability of the ANS to regulate an organ's function under both emergency situations and resting conditions is possible due to:

dual innervation.

The sympathetic and parasympathetic divisions can maintain a balance in most organs and that ensures that the body's needs are met appropriately at all times due to:

dual innervation.

The preganglionic and postganglionic fibers of the parasympathetic divisions secrete the neurotransmitter ACh. Drugs that stimulate ACh release will:

enhance the effects of the parasympathetic division, such as excessive drooling, diarrhea, and poor distance vision. Stimulation of ACh release will trigger many of the effects that the parasympathetic nervous system has on its target cells. These include increasing saliva release (drooling), pupil constriction and adjustment of the lens for near vision (poor distance vision), and excess digestive activity (diarrhea).

Postganglionic neurons of the autonomic nervous system __________.

have cell bodies located within autonomic ganglia Cell bodies of postganglionic neurons are located within autonomic ganglia, while their axons extend to various target organs/target cells.

Parasympathetic tone is normally dominant in the __________.

heart The parasympathetic nervous system is normally dominant in the heart and keeps the heart rate at an average of 72 beats per minute.

Drugs known as β-blockers are most likely to affect __________.

heart rate

The part of the central nervous system that regulates the autonomic centers is the:

hypothalamus

Which of the following can be a side effect of a drug that stimulates the parasympathetic nervous system?

increased salivation The parasympathetic division causes a stimulation of salivary gland secretions, so a drug that stimulates the parasympathetic branch can cause the condition known as hypersalivation.

If a medication were able to selectively block nicotinic receptors on sympathetic postganglionic neurons, it would:

inhibit stimulation of sympathetic postganglionic receptors. When preganglionic sympathetic neurons function normally, they stimulate postganglionic cell bodies by releasing ACh onto nicotinic receptors. Blocking these receptors would prevent stimulation of postganglionic sympathetic neurons, which will allow it to behave the same as stimulating receptors on the preganglionic neurons.

Alpha-2 adrenergic receptors in the axon terminals of sympathetic preganglionic neurons:

inhibit the preganglionic neuron by hyperpolarizing its axon terminal This is an example of a negative feedback loop designed to prevent excess sympathetic activity.

What neurotransmitter is released by both preganglionic and postganglionic parasympathetic neurons?

Acetylcholine

What neurotransmitter is released by the axon of a sympathetic preganglionic neuron to communicate with a sympathetic postganglionic neuron?

Acetylcholine

Which of the following neurotransmitters does not bind to adrenergic receptors?

Acetylcholine

Which of the following nervous system activities is not an effect of norepinephrine?

Blood glucose levels decrease.

Acetylcholine binds to:

nicotinic and muscarinic receptors.

Athletes who are well conditioned will have strong:

parasympathetic tone.

The gray rami communicantes contain:

postganglionic sympathetic neurons.

Neurons that transmit efferent signals between the CNS and autonomic ganglia are called __________.

preganglionic neurons. Cell bodies of preganglionic neurons reside in the brain stem or spinal cord. Preganglionic neurons stimulate postganglionic neurons.

You are developing a new drug that treats asthma symptoms by stimulating bronchodilation. This drug should mimic

stimulating the sympathetic nervous system. Many bronchodilator drugs work by stimulating beta-2 adrenergic receptors, which are also stimulated by the sympathetic nervous system.

Which of the following is NOT an organ innervated by the parasympathetic nervous system?

sweat glands Sweat glands, blood vessels, arrector pili muscles, and the adrenal medulla are only innervated by the sympathetic division of the ANS.

The effects of the ________ nervous system are generally antagonistic to the effects of the parasympathetic nervous system.

sympathetic

Nicotinic cholinergic receptors are found at __________.

sympathetic and parasympathetic ganglia The receptors for ACh on postganglionic neurons are nicotinic cholinergic receptors.

Sympathetic preganglionic neurons synapse in:

sympathetic chain and collateral ganglia.

Most of the cell bodies of the sympathetic postganglionic neurons are found in the:

sympathetic chain ganglia.

About 90% of parasympathetic innervation to the body occurs by the:

vagus nerves.

Myelinated preganglionic fibers that connect the anterior rami of spinal nerves with the sympathetic chain ganglia travel through:

white rami communicantes.

Which of the following statements is incorrect?

Adrenal ganglia are located within the kidney.

Which of the following terms refers to the synapse found between the preganglionic and postganglionic neuron of a visceral reflex arc?

Autonomic ganglion

Which of the following effects is NOT one of the characteristic of the sympathetic nervous system action on its target cells?

Bronchoconstriction The sympathetic division causes dilation of bronchioles.

Which of the following targets does the vagus nerve (CN X) innervate?

Cardiac muscle cells

Which of the following features is not associated with the sympathetic nervous system?

Craniosacral division

Decreased parasympathetic stimulation could cause which of the following actions?

Dry mouth

Which of the following cranial nerves is not involved in the parasympathetic nervous system?

Hypoglossal nerve (CN XII)

What part of the brain largely controls homeostatic functions?

Hypothalamus

Which of the following organs is innervated by parasympathetic sacral nerves?

Last segment of the large intestine

_____________ are long; ______________ are short.

Parasympathetic preganglionic neurons; parasympathetic postganglionic neurons

A nurse injected a patient with a drug that will selectively bind to and activate Alpha-2 receptors, i.e., Alpha-2 agonists, to:

Lower the patient's blood pressure Alpha-2 receptors are different from the other adrenergic receptors ( we find most of them in the membrane of preganglionic sympathetic neurons rather than in peripheral target cells. Normally an action potential in a preganglionic neuron leads to ACh release, which stimulates the postganglionic neuron. However, when norepinephrine binds to Alpha-2 receptors, the axon terminal is hyperpolarized, slowing, or even canceling the action potential. As a result, the preganglionic neuron stops stimulating the postganglionic neuron, which dampens or even shuts off the sympathetic response.

Which division of the nervous system functions to conserve energy and replenish the supply of nutrients?

Parasympathetic

Which nervous system division works antagonistically to the sympathetic nervous system?

Parasympathetic nervous system

In which of the following locations are autonomic ganglia located?

Peripheral nervous system (PNS)

Which of the following is an effect of the parasympathetic nervous system?

Relaxation of digestive and urinary sphincters will allow for urination and defecation. Urination and defecation follow digestion, so it makes sense that they are stimulated by the parasympathetic branch.

An elderly woman taking medication to lower her blood pressure will see effects on her entire sympathetic nervous system. What would happen if she is faced with an emergency?

She will be less able to regulate her blood pressure and make the necessary adjustments during the emergency. The sympathetic nervous system is the "fight or flight" division, meaning that it prepares the body for emergencies. Blocking many of the effects of this system will make the individual less able to regulate her blood pressure and to make other necessary adjustments during an emergency.

The preganglionic axons of CN VII may extend to which of the following ganglia?

Submandibular

What two systems are interfaced by the adrenal medulla?

Sympathetic nervous system and endocrine system

What is responsible for keeping blood vessels partially constricted at all times?

Sympathetic tone

The autonomic tone is the constant activity and balance of both the sympathetic and parasympathetic nervous system. Consider what the effects would be if the parasympathetic tone was dominant in the airways.

The airways would exhibit bronchoconstriction. The dominance of parasympathetic tone would lead to bronchoconstriction because parasympathetic input would outweigh sympathetic input to the smooth muscles of the airways. When the bronchioles are constricted, it will be difficult to enter "flight or fight" mode because you will not allow enough air into the lungs.

Why do individuals who suffer from brainstem injuries have difficulty with their autonomic functions?

The brainstem contains the autonomic centers and the cell bodies of many parasympathetic neurons that regulate autonomic responses. The reticular formation is a group of nuclei in the brainstem, which contain areas called autonomic centers. These centers control the activity of preganglionic sympathetic and parasympathetic neurons. Although the hypothalamus does exert some degree of control over these centers, the reticular formation can function even if the circuits connecting it to the hypothalamus are severed. This indicates that the reticular formation can control many of our most critical autonomic functions, such as heart rate and blood pressure, on its own. If the reticular formation is damaged, the individual will have difficulty maintaining homeostasis.

Motor impulses are sent from the CNS to postganglionic neurons in step __________.

The cell bodies of preganglionic neurons are located in the CNS. They form synapses with postganglionic neurons inside autonomic ganglia.

Where is a postganglionic cell located?

The cell body is located in the ganglion; the axon comes after the ganglion. The cell body is located in the ganglion; the axon comes after the ganglion.

Which of the following characteristics are not associated with the autonomic nervous system?

The effectors are primarily skeletal muscles.

Which of the following divisions of the nervous system is often called the "rest and digest" division of the nervous system?

The parasympathetic nervous system is often described as the ""rest and digest"" division of the ANS. This reflects its role in digestion and in maintaining the body''s homeostasis when at rest.

Which of the following statements best characterizes the function of the parasympathetic nervous system?

The parasympathetic nervous system maintains homeostasis when the body is at rest.

The branch of the autonomic nervous system that activates when you are resting and digesting is the

The parasympathetic nervous system takes over when the body is resting, repairing, and digesting.

Which division of the nervous system is responsible for voluntary control of skeletal muscle?

The somatic nervous system innervates skeletal muscle using a single motor neuron.

When witnesses lie under oath, their pupils dilate. This effect is caused by _____.

The sympathetic nervous system causes pupils to dilate. Another sign of lying is increased sweating, which is also a sympathetic effect.

Where do the preganglionic neurons of the sympathetic nervous system originate?

Thoracolumbar region of the spinal cord

Autonomic centers are located in the __________.

reticular formation Autonomic centers in the reticular formation contain neurons that control the activity of preganglionic sympathetic and parasympathetic neurons.

All of the following features are associated with the parasympathetic division except:

short preganglionic axons and long postganglionic axons.

Somatic motor neurons innervate __________.

skeletal muscle cells

Beta-blockers are a class of drugs that act as adrenergic antagonists. Beta-blockers will have an effect at __________.

sympathetic target organs Adrenergic receptors are found at sympathetic target organs, so this is where the drug will have an effect.

Parasympathetic preganglionic neurons synapse with postganglionic neurons in:

terminal ganglia.

Autonomic tone is

the balance between sympathetic and parasympathetic activity.