A&P - Autonomic Nervous System (Ch. 14) Questions

Second messengers activated

Alpha α receptor

Which receptors provide information on the volume of digestive tract segments?

Baroreceptors Stimulation of the digestive tract receptors triggers reflex movement of materials along the tract.

20.2Activation of adenylate cyclase

Beta β receptor

Vasomotor reflexes

Changes in diameter of peripheral vessels

Cranial nerve X

Chemoreceptors of aortic bodies

Cranial nerve IX

Chemoreceptors of carotid bodies

Direct light and consensual light reflexes

Constriction of pupils of both eyes

Pancreas (sympathetic)

Decreased exocrine secretion

pancreas

Decreased secretion of insulin

pupillary reflex

Dilation of pupils

What is the extensive network of neurons and nerve networks located in the walls of the digestive tract known as?

Enteric nervous system

nicotinic receptors

Exposure to ACh always causes excitation of the ganglionic neuron or muscle fiber by opening chemically gated channels in the postsynaptic membrane.

Pons

Higher levels of respiratory control

Which of the following cranial nerves form a portion of the parasympathetic nervous system (PNS)?

III, VII, IX, X The parasympathetic division of the autonomic nervous system, known as the cranio-sacral division, includes neurons whose axons emerge from the brain stem and the sacral segments of the spinal cord.

A general elevation in muscle tone through stimulation of the _______ and lateral pathways is an effect of sympathetic activation.

In this effect, the person looks tense and may begin to shiver.

Pineal gland

Increased secretion of melatonin

Ciliary ganglion

Intrinsic eye muscles

PNS ganglia

Located near the vertebral column

Postganglionic fibers

Long

Cranial nerves V, VII, IX, and X

Mouth, palate, pharynx, larynx, trachea, esophagus, and associated vessels and glands

G protein activation

Muscarinic receptor

Otic ganglion

Nasal glands, tear glands, and salivary glands

Sacral spinal cord S2-S4

Neurons controlling parasympathetic visceral reflexes

Spinal cord T1-L2

Neurons controlling sympathetic visceral reflexes

Opening of chemically gated channels in the postsynaptic membrane

Nicotinic receptor

The sympathetic and parasympathetic effects on the airways of the respiratory system are to _______ and decrease the airway diameters, respectively.

Note that in this case the effects of both divisions are opposing, not complementary.

Baroreceptor reflex, Gastric and intestinal reflexes, Direct light and consensual light reflexes

Parasympathetic

Normally NE, sometimes NO or ACh

Postganglionic neurotransmitter

Acetylcholine

Preganglionic neurotransmitter

Medulla oblongata

Processing centers for complex visceral reflexes (sympathetic and parasympathetic)

salivary glands (sympathetic)

Production of viscous secretion containing mucins and enzymes

Baroreceptors are stretch receptors that monitor changes in ____

Recall that baroreceptors and chemoreceptors play key roles in the control of visceral function by the ANS.

____ reflexes predominate in the enteric nervous system of the ANS.

Recall that the enteric nervous system operates largely outside of the awareness and control of the CNS.

The stimulation of alpha-1 receptors and alpha-2 receptors on target cells generally results in excitatory ________ and effects, respectively.

Recall that the stimulation of alpha receptors activates enzymes on the inside of the plasma membrane.

Preganglionic fibers (PSNS)

Relatively long

Postganglionic fibers (SNS)

Relatively short

Neurohypophysis

Secretion of ADH

Adrenal gland

Secretion of epinephrine and norepinephrine

Preganglionic fibers

Short

In the parasympathetic division of the ANS, the preganglionic fibers that form distinct pelvic nerves innervate _______ ganglia in the walls of the kidneys, urinary bladder, terminal portions of the large intestine, and sex organs.

Such preganglionic fibers carry the sacral parasympathetic output.

Cardioacceleratory reflex, Pupillary reflex, Vasomotor reflexes

Sympathetic

Which statement regarding innervation in the parasympathetic division is false?

The facial nerve alone provides approximately 75 percent of all parasympathetic outflow. True: Numerous branches of the vagus nerve intermingle with sympathetic preganglionic and postganglionic fibers. Preganglionic fibers in the sacral segments of the spinal cord do not join the ventral roots of the spinal nerves. The preganglionic fibers in the sacral segments of the spinal cord carry the sacral parasympathetic output.

Spinal segments S2-S4 (PSNS)

The location of CNS visceral motor neurons

lateral gray horns of spinal segments T1-L2

The location of CNS visceral motor neurons

In the ANS, motor neurons of the CNS synapse on visceral motor neurons in autonomic ganglia whose neurons control _______ effectors.

The neurons in the integrative centers for autonomic activity are comparable to the upper motor neurons in the SNS.

Alpha α receptors

The stimulation of these receptors activates enzymes on the inside of the plasma membrane.

Muscarinic receptors

The stimulation of these receptors produces longer-lasting effects that reflect the activation or inactivation of specific enzymes, which can be either excitatory or inhibitory.

Beta β receptors

The stimulation of these receptors triggers changes in the metabolic activity of the target cell.

Chemoreceptors

These receptors are specialized neurons found within the medulla oblongata and elsewhere in the brain, near the origin of the internal carotid arteries on each side of the neck, and between the major branches of the aortic arch.

Baroreceptors

These receptors consist of free nerve endings that branch within the elastic tissues in the walls of hollow organs, blood vessels, and tubes in the respiratory, digestive, or urinary tract.

Which is true regarding muscarinic receptors?

They are located at cholinergic neuromuscular or neuroglandular junctions.

PNS Ganglia

Typically embedded in the tissues of the target organ

Collateral ganglia

Visceral effectors in the abdominopelvic cavity

Dorsal roots of spinal nerves S2-S4

Visceral organs located between the diaphragm and the pelvic cavity

Dorsal roots of spinal nerves T1-L2

Visceral organs located between the diaphragm and the pelvic cavity

Which of the following is not an effect produced by activation of the parasympathetic division of the ANS?

accelerated breakdown of glycogen in muscle and liver cells True: stimulation and coordination of defecation, contraction of respiratory passageways, reduction in heart rate and force of contraction

Cellular inhibition due to a reduction in cAMP levels is a result of the stimulation of which receptors?

adrenergic α2 (alpha-2) receptors The effects of sympathetic and parasympathetic stimulation result primarily from the interactions of norepinephrine, epinephrine, and acetylcholine with their respective receptors.

In the autonomic nervous system:

axons of preganglionic neurons leave the CNS and synapse on visceral motor neurons in peripheral ganglia.

Which of the following is not a sympathetic collateral ganglion?

ciliary ganglion The collateral ganglia of the sympathetic division target visceral effectors in the abdominopelvic cavity.

Sphincters (sympathetic)

decreased exocrine secretion

The stimulation of adrenergic β2 (beta-2) receptors results in which of the following?

elaxation of smooth muscle in the respiratory passages and in the blood vessels of skeletal muscle Adrenergic beta receptors are located on the plasma membranes of cells in many organs.

Which of the following ANS structures innervate visceral effectors?

ganglionic neurons The somatic nervous system and autonomic nervous system are organized in parallel, and are integrated at the level of the brain stem.

Which sympathetic structures of the ANS affect target organs throughout the body through the release of hormones into the general circulation?

ganglionic neurons in adrenal medullae Recall that the sympathetic division prepares the body for heightened levels of somatic activity.

Liver (sympathetic)

glycogen breakdown

In a crisis, sympathetic activation is controlled by sympathetic centers in which structure(s)?

hypothalamus The sympathetic division of the ANS can change the activities of tissues and organs by releasing norepinephrine at peripheral synapses, and by distributing epinephrine and norepinephrine throughout the body via the bloodstream.

cardioacceleratory reflex

increase in heart rate and force of contraction

An increase in heart rate to maximum levels will occur with:

increased sympathetic stimulation combined with parasympathetic inhibition.

Secretory glands (sympathetic)

inhibition

In the parasympathetic division of the ANS, where do the pelvic nerves synapse?

intramural ganglia

Long reflexes are not/do not:

involve sensory neurons and interneurons whose cell bodies are located within the autonomic ganglia. Most visceral functions are controlled by visceral reflexes, which consist of a receptor, a sensory neuron, a processing center, and visceral motor neuron(s).

Vasomotor, swallowing, and coughing centers are found in which of the following?

medulla oblongata The levels of activity in the sympathetic and parasympathetic divisions of the ANS are controlled by centers that regulate specific visceral functions.

The neurons in the respiratory centers of the medulla oblongata monitor:

pH and PCO2 in CSF.

Splanchnic nerves are formed by:

preganglionic fibers on their way to the collateral ganglia. Every spinal nerve has a gray ramus that carries sympathetic fibers for distribution in the body wall and limbs.

Which of the following parasympathetic ganglia innervates the lacrimal gland?

pterygopalatine ganglion In the parasympathetic division, a typical preganglionic fiber synapses on six to eight ganglionic neurons.

baroreceptor reflex

reduction in heart rate and force of contraction

Thalamus

relay of sensory information

Which of the following structures is not innervated by the parasympathetic nervous system?

sweat glands Recall that the ANS provides precise control over visceral functions, and many vital organs receive dual innervation.

Pterygopalatine and submandibular ganglia

target organ: Nasal glands, tear glands, and salivary glands

Intramural ganglia

target organ: Visceral organs of neck, thoracic cavity, and most of abdominal cavity

Which sympathetic visceral reflex is coordinated in the medulla oblongata?

vasomotor reflex