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