Chapter 14 ANS

Preganglionic fibers of parasympathetic neurons are present in all of the following cranial nerves except

XII.

Describe an intramural ganglion. (Module 14.3B)

a group of neurons embedded in the tissues of the target organ.

Most sympathetic effector junctions release norepinephrine but a significant number release acetylcholine instead. Which of these is an example of an organ of the cholinergic type?

a sweat gland

Sympathetic nerves

are bundles of postganglionic fibers that innervate organs within the thoracic cavity.

Muscarinic receptors

are normally activated by acetylcholine.

Ganglionic neurons usually synapse with preganglionic neurons in the ________ and have axons that innervate ________.

autonomic ganglia; visceral effectors

A certain drug decreases heart rate by blocking a receptor on cardiac pacemaker cells. This drug probably binds to ________ receptors.

beta-1 adrenergic

Which of the following would lead to increased heart rate?

both increased sympathetic input and decreased parasympathetic input

Which of the following is not a parasympathetic ganglion?

celiac

What brain structure is considered to be the headquarters for the ANS?

hypothalamus

Which brain area is considered to be the headquarters of the ANS?

hypothalamus

The integrative centers for autonomic activity are located in the

hypothalamus.

What brain structure relays somatosensory information? (Module 14.11B)

thalamus

The statement "Its ganglia are usually near or within the end organ" is

true only for the parasympathetic nervous system.

Define visceral reflex. (Module 14.9A)

A visceral reflex is an autonomic reflex initiated in the viscera. It can be modified, facilitated, or inhibited by higher centers, especially those in the hypothalamus.

Which of the following statements about adrenergic receptors is true?

All of the answers are correct.

Define baroreceptors. Where are baroreceptors located within the body? (Module 14.10A)

Baroreceptors are stretch receptors that detect changes in pressure. They are located along the digestive tract, within the walls of the urinary bladder, in the carotid and aortic sinuses, and in the lungs.

Define dual innervation. (Module 14.8A)

Dual innervation means that a given body system receives instructions from both the sympathetic and parasympathetic divisions of the ANS.

Compare the anatomy of the sympathetic division with that of the parasympathetic division. (Module 14.2B)

In the SNS, axons emerge from the thoracic and lumbar segments of the spinal cord and innervate ganglia relatively close to the spinal cord. In the PNS, axons emerge from the brainstem and sacral segments of the spinal cord and innervate ganglia very close to or within the target organs.

Which of the following is true for the craniosacral division?

It is also called the parasympathetic division of the ANS.

Compare nicotinic receptors and muscarinic receptors. (Module 14.6B)

Nicotinic receptors are acetylcholine receptors on the surface of sympathetic and parasympathetic ganglionic cells. Muscarinic receptors are acetylcholine G protein-coupled receptors located at all parasympathetic neuromuscular and neuroglandular junctions, and at a few sympathetic neuromuscular and neuroglandular junctions.

Which of the following statements concerning the parasympathetic division of the autonomic nervous system is false?

Preganglionic fibers are relatively short and postganglionic fibers are relatively long.

Compare short reflexes with long reflexes. (Module 14.9B)

Short reflexes are autonomic responses that bypass the CNS, whereas long reflexes involve interneurons within the CNS and autonomic delivery of motor commands to the effectors.

Identify somatic effectors and visceral effectors. (Module 14.7C)

Somatic effectors are skeletal muscle. Visceral effectors are smooth muscle, cardiac muscle, glands, and adipose tissue.

Define splanchnic nerves. (Module 14.4A)

Splanchnic nerves are three groups of nerves — cardiopulmonary, abdominopelvic (greater, lesser, and lumbar), and pelvic (sacral) — that supply the viscera.

Describe the ENS. (Module 14.2C)

The ENS is a division of the nervous system consisting of a network of neurons and nerve networks in the walls of the digestive tract that primarily operates locally, without instructions

Compare the SNS with the ANS. (Module 14.1A)

The SNS provides conscious and subconscious control over skeletal muscles. The ANS controls the visceral effectors: smooth muscle, glands, cardiac muscle, and adipocytes.

Which nerve carries most of the parasympathetic outflow? (Module 14.4C)

abducens nerve

Explain the function of autonomic ganglia. (Module 14.1C)

They are ganglionic neurons that innervate visceral effectors.

Describe the solitary nuclei. (Module 14.9C)

They are large masses of gray matter on each side of the medulla oblongata that serve as processing sorting centers for visceral sensory information.

Describe the role of preganglionic neurons.

They are part of visceral reflex arcs, and most of their activity is a direct reflex response, rather than responses to commands from the hypothalamus.

Collateral ganglia contain neurons that innervate tissues and organs in which cavity?

abdominopelvic

What neurotransmitter is released by all parasympathetic neurons? (Module 14.5B)

acetylcholine

Which neurotransmitter is released at the sympathetic chain ganglia?

acetylcholine

Postganglionic sympathetic axons release the neurotransmitter ________ at their effector junctions.

acetylcholine or nitric oxide or norepinephrine

An inhaler used to treat airway constriction in asthma or allergy might contain a drug that

activates β2 adrenergic receptors or blocks muscarinic cholinergic receptors.

Specialized ganglionic sympathetic neurons that release hormones into the bloodstream are found within the

adrenal glands.

Neurons that use norepinephrine as a transmitter are called

adrenergic

Autonomic tone is an important aspect of ANS function because it

allows ANS neurons to increase or decrease their activity, providing a range of control options.

A neuron with nicotinic receptors is exposed to acetylcholine. This will not lead to

binding of the nicotine to the channel.

A decrease in the autonomic tone of the smooth muscle in a blood vessel would result in

both an increase in vessel diameter and an increase in blood flow through the vessel.

In which of the following organs are both chemoreceptors and baroreceptors associated with respiratory autonomic reflexes?

both aorta and carotid arteries

The adrenal medullae secrete

both epinephrine and norepinephrine.

Cell bodies of preganglionic neurons of the autonomic nervous system are located

both in the brain stem and in the lateral gray horns of the spinal cord.

Control of the diameter of the respiratory passages depends upon

both parasympathetic and sympathetic levels of stimulation.

Dual innervation refers to an organ receiving

both sympathetic and parasympathetic innervation.

Sympathetic and parasympathetic fibers that innervate the heart pass through the

cardiac plexus

Name the plexuses innervated by the vagus nerve. (Module 14.4B)

cardiac, celiac, inferior mesenteric, and hypogastric plexuses

Clusters of ganglionic sympathetic neurons lying along either side of the spinal cord are called sympathetic ________ ganglia.

chain

Which type of receptor is sensitive to changes in blood pH? (Module 14.10B)

chemoreceptors

Clusters of ganglionic sympathetic neurons that innervate organs in the abdominopelvic region are called ________ ganglia.

collateral

Autonomic motor neurons

conduct impulses to smooth and cardiac muscles and glands.

Splanchnic nerves

consist of axons that synapse in collateral ganglia.

During sympathetic activation, which of the following would not occur?

constriction of pupil

Each of the following effects is associated with the action of postganglionic sympathetic fibers except

decreased heart rate.

Which of the following is an example of a parasympathetic visceral reflex?

defecation reflex

The parasympathetic nervous system is especially active during which physiological state(s)?

digestion

Injury to the neurons of a collateral ganglion would affect the function of the

digestive tract.

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.

Parasympathetic functions include all of the following except

dilation of the airways.

Most vital organs receive ________ innervation. That is, they receive input from both sympathetic and parasympathetic divisions.

dual

Drugs known as beta-blockers may be useful for treating

excessive heart rate.

Mary accidentally ate poisonous mushrooms that contain muscarine. What would not occur?

feeling of euphoria and increased energy

Preganglionic fibers leave the CNS and then synapse on

ganglionic neurons.

Which structure carries postganglionic fibers for distribution in the body wall and limbs?

gray ramus

Stimulation of the neurons in the celiac ganglion would lead to

hydrolysis of liver glycogen reserves

Stimulation of the beta receptors on heart muscle cells does not result in

inactivation of G proteins.

Which of the following would be an example of higher-level control of autonomic function?

increased heart rate when you see a person you fear

Sympathetic activation leads to all of the following except

increased release of insulin.

Parasympathetic stimulation

increases gastric motility.

Sympathetic innervation of the urinary bladder is by way of the ________ ganglion.

inferior mesenteric

The celiac ganglia do not innervate the

intestines.

Preganglionic fibers of parasympathetic pelvic nerves synapse on neurons located within ________ ganglia.

intramural

Injury to the cervical sympathetic ganglia would not affect the function of the

lacrimal glands.

Preganglionic neurons of the sympathetic nervous system are located in the

lateral gray horns of segments T1 to L2 of the spinal cord.

As the result of an accident, the white rami of spinal nerves T1 and T2 on the left side of Brad's body are severed. What organ(s) would you expect might be affected by this injury?

left pupil and heart

In general, parasympathetic preganglionic fibers are ________ and postganglionic fibers are ________.

long; short

The sympathetic collateral ganglia include all of the following except the

lumbar

Sweat glands contain ________ receptors

muscarinic cholinergic

Nicotinic receptors

open chemically gated sodium ion channels.

Baroreceptors are not found in the

oral cavity.

The ________ division of the autonomic nervous system is known as the "rest and digest" division.

parasympathetic

Intramural ganglia in the large intestine, urinary bladder, and reproductive organs are innervated by the ________ nerves.

pelvic

A visceral motor neuron whose cell body is within the CNS is called a(n) ________ neuron.

preganglionic

What type of neuron of the parasympathetic division exits the brain stem?

preganglionic neuron

Starting in the spinal cord, trace the path of a nerve impulse through the sympathetic ANS to its target organ in the abdominal cavity. (Module 14.3A)

preganglionic neurons (T1-L2) — collateral ganglia — ganglionic neurons — visceral effectors in abdominopelvic cavity

Which of the following visceral reflexes is not coordinated by the medulla oblongata?

pupillary reflex

Ganglionic neurons in the adrenal gland

release epinephrine into blood capillaries.

The stimulation of beta-adrenergic receptors does not lead to

release of calcium from the ER.

Stimulation of α1 adrenergic receptors by norepinephrine results in

release of calcium ions from intracellular stores.

Visceral reflex arcs can bypass CNS neurons in ________ reflexes.

short

Which of the following is exclusive to the sympathetic division of the ANS?

short pre-ganglionic fibers

In general, sympathetic preganglionic fibers are ________ and postganglionic fibers are ________.

short; long

Ganglionic neurons innervate as all of the following except

skeletal muscle.

7) All of the following are visceral effectors except

skeletal muscles.

Chemoreceptors that play an important role in reflexive control of respiratory function are not affected by

sodium ion concentration.

Name the two types of motor pathways. (Module 14.7B)

somatic and visceral

Two terms that both refer to internal organs are

splanchnic and viscera.

Preganglionic fibers that innervate the collateral ganglia form the

splanchnic nerves.

A person is confronted by a dangerous dog. His heart begins to race and beat strongly, his pupils dilate, and his hairs stand up. These signs are not the result of

stimulation of the pancreas to release insulin.

Postganglionic fibers that innervate targets in the body wall or thoracic cavity originate on neurons within

sympathetic chain ganglia.

Identify two major divisions of the ANS. (Module 14.2A)

sympathetic division and parasympathetic division

Which division of the ANS is responsible for the physiological changes you experience when startled by a loud noise? (Module 14.2D)

sympathetic division of the ANS

In general, autonomic tone of peripheral blood vessels increases when

sympathetic stimulation is increased.

The sympathetic division of the ANS is also known as which of the following?

thoracolumbar division

1) The statement "There is always a synapse in a peripheral ganglion between the CNS and the effector organ" is

true for both the parasympathetic and sympathetic nervous systems.

The statement "It controls the diameter of the pupil" is

true for both the parasympathetic and sympathetic nervous systems.

The statement "Preganglionic axon terminals release acetylcholine" is

true for both the parasympathetic and sympathetic nervous systems.

The statement "It initiates contraction of urinary bladder smooth muscle" is

true only for the parasympathetic nervous system.

The statement "It sends its preganglionic fibers to terminal or intramural ganglia" is

true only for the parasympathetic nervous system.

The statement "Its postganglionic axons always use acetylcholine as the neurotransmitter" is

true only for the parasympathetic nervous system.

Almost 75 percent of all parasympathetic outflow travels along the ________ nerve(s).

vagus

Which of the following provides preganglionic parasympathetic innervation to structures in the thoracic and abdominopelvic cavities?

vagus nerves