Chapter 14
cardiac and smooth muscle, glands, and adipose tissue are directly innervated by ____.
ganglionic neurons
describe the solitary nuclei
The solitary nuclei are large masses of gray matter on each side of the medulla oblongata that serve as processing and sorting centers for visceral sensory information.
name the plexuses innervated by the vagus nerve.
the vagus nerve innervates the cardiac plexus, celiac plexus, inferior mesenteric plexus, and the hypogastric plexus
define splanchnic nerves.
three groups of nerves --- cardiopulmonary, abdominopelvic (greater, lesser, and lumbar), and pelvic (sacral) --- that supply the viscera
which of the following is NOT a visceral effector? a. glands b. smooth muscle c. cardiac muscle d. skeletal muscle
d. skeletal muscle
describe an intramural ganglion.
group of neurons embedded in the tissue of a target organ
visceral reflexes are most likely to be influenced by which of the following?
hypothalamus
activation of the parasympathetic division of the ANS results in ____.
increased motility and blood flow in the digestive tract
what physiological changes are typical in a tense or anxious person?
increased sympathetic stimulation typically causes: >increased alertness (being "on edge"); >a feeling of increased energy; increased heart rate, blood pressure, and breathing rate; >increase in muscle tone; >and mobilization of energy reserves
which of the following is NOT a group of splanchnic nerves? --cardiopulmonary --pelvic --abdominopevlic or --inferior mesenteric
inferior mesenteric
which best describes a preganglionic neuron?
its cell body is within the CNS
ACh is a neurotransmitter released by all ___ neurons.
parasympathetic
during digestion, what part of the nervous system is active?
parasympathetic
which of the following is not a plexus of the vagus nerve?
pelvic
starting in the spinal cord, trace the path of a nerve impulse through the sympathetic ANS to its target organ in the abdominopelvic cavity.
preganglionic neurons (T1-L2) ---> collateral ganglia ---> ganglionic neurons(postganglionic fibers) ---> visceral effectors in abdominopelvic cavity
what brain structure relays somatosensory information?
the thalamus
which nerve carries most of the parasympathetic outflow?
the vagus nerve (X)
----DESCRIBE THE HIERARCHY OF INTERACTING LEVELS OF CONTROL IN THE ANS, BEGINNING WITH THE HYPOTHALAMUS.----
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--QUIZ QUESTIONS--
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----DESCRIBE THE ROLE OF THE ANS IN MAINTAINING HOMEOSTASIS DURING UNCONSCIOUSNESS.----
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----DESCRIBE THE STRUCTURES AND FUNCTIONS OF THE SYMPATHETIC AND PARASYMPATHETIC DIVISIONS OF THE ANS----
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----DESCRIBE THE TYPES OF SYMPATHETIC AND PARASYMPATHETIC RECEPTORS AND THEIR ASSOCIATED NEUROTRANSMITTERS.----
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--KAHOOT QUESTIONS--
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Compare nicotinic receptors with muscarinic receptors.
>Nicotinic receptors are acetylcholine (ACh) receptors on the surfaces of sympathetic and parasympathetic ganglionic cells >muscarinic receptors are ACh membrane receptors that are located at all parasympathetic neuromuscular and neuroglandular junctions, and at a few sympathetic neuromuscular and neuroglandular junctions.
Compare short reflexes with long reflexes.
>Short reflexes are autonomic responses that bypass the CNS. >long reflexes involve interneurons within the CNS and autonomic delivery of motor commands to the effectors.
compare and contrast alpha and beta receptors.
>both alpha receptors and beta receptors are adrenergic receptors on the membranes of target cells. >alpha receptors are more sensitive to NE(Norepinephrine) than beta receptors, but both receptors are stimulated by E(Epinephrine). >alpha-1 receptor stimulations typically excites the target cell, and alpha-2 receptor stimulation generally inhibits the target cell. >stimulation of beta receptors may result in excitation or inhibition of the target cell.
describe the roll of preganglionic neurons.
>preganglionic neurons are part of the visceral reflex arcs. >they are involved mostly in direct reflex responses, rather than responses to commands the hypothalamus.
which cranial nerve provides roughly 75 percent of all parasympathetic outflow?
CN X-Vagus
explain the function of autonomic ganglia.
Ganglionic neurons of autonomic ganglia innervate visceral effectors.
Harry has a brain tumor that is pressing against his hypothalamus. Explain the effect on autonomic function.
a brain tumor pressing on the hypothalamus could interfere with autonomic function because the hypothalamus receives visceral sensory information and controls both sympathetic and parasympathetic functions.
which statement is true regarding the ANS? a. the sympathetic and parasympathetic divisions of the ANS never innervate the same organ. b. the integrative centers for autonomic activity are located in the hypothalamus. c. there is a single lower motor neuron in the autonomic centers of the ANS. d. ganglionic neurons in autonomic ganglia control skeletal muscle.
b. the integrative centers for autonomic activity are located in the hypothalamus.
which of the following is NOT an effect of the parasympathetic nervous system? a. decreased metabolic rate b. increased motility and blood flow in the digestive tract c. reduced digestive and urinary functions d. decreased heart rate and blood pressure
c. reduced digestive and urinary functions
which of the following receptors will detect changes in pH?
chemoreceptors
which type of receptor is sensitive to changes in blood pH?
chemoreceptors
name the two types of motor pathways.
somatic and visceral
what provided conscious and subconscious control over skeletal muscles?
somatic nervous system
the division of the autonomic nervous system that prepares the body for activity and stress is the ___.
sympathetic division
identify two major divisions of the ANS.
sympathetic division and parasympathetic division
what brain structure is considered to be the headquarters for the ANS?
the hypothalamus
----DISCUSS THE RELATIONSHIP BETWEEN THE TWO DIVISIONS OF THE ANS AND THE SIGNIFICANCE OF DUAL INNERVATION.----
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----DEFINE A VISCERAL REFLEX, AND EXPLAIN THE SIGNIFICANCE OF SUCH REFLEXES.----
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----DESCRIBE THE INNVERVATION PATTERNS OF THE SYMPATHETIC AND PARASYMPATHETIC DIVISIONS OF THE ANS.----
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----EXPLAIN THE ROLES OF BARORECEPTORS AND CHEMORECEPTORS IN HOMEOSTASIS.----
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----LIST THE DIVISIONS OF THE ANS AND THE GENERAL FUNCTIONS OF EACH.----
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----DESCRIBE THE MECHANISMS OF NEUROTRANSMITTER RELEASE IN THE ANS, AND EXPLAIN THE EFFECTS OF NEUROTRANSMITTERS ON TARGET ORGANS AND TISSUES.----
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----DESCRIBE THE CONTROL OF SKELETAL MUSCLES BY THE SNS AND CONTROL OF VISCERAL EFFECTORS BY THE ANS.----
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identify somatic effectors and visceral effectors.
>The somatic effector is skeletal muscle. >The visceral effectors are smooth muscles, glands, cardiac muscle, and adipocytes.
compare the Somatic Nervous System with the Autonomic Nervous System.
>The somatic nervous system provides conscious and subconscious control over skeletal muscles. >The autonomic nervous system controls the visceral effectors: smooth muscle, glands, cardiac muscle, and adipocytes.
describe the ENS.
>a division of the nervous system >consists of an extensive network of neurons and nerve networks in the walls of the digestive tract. >although it may be influenced by the sympathetic and parasympathetic divisions, the ENS initiates and coordinates complex visceral reflexes locally, without instructions from the CNS.
explain autonomic tone and its significance in controlling visceral function.
>autonomic tone is the background level of activity in sympathetic or parasympathetic motor neurons under resting conditions. >it provides a mechanism for fine control of visceral function because it allows a resting neuro to be less active or more active rather than to simply switch from off to on. >this is particularly important when only one division innervates a visceral organ or when an organ (e.g., the heart) must be precisely controlled over a broad range of activity levels.
List general responses to increased sympathetic activity and to parasympathetic activity.
>general responses to increased sympathetic activities includes: heightened mental alertness, increased metabolic rate, reduced digestive and urinary functions, activation of energy reserves, increased respiratory rate and dilation of respiratory passageways, elevated heart rate and blood pressure, and activation of sweat glands. >general responses to increased parasympathetic activity include decreased metabolic rate, decreased heart rate, and blood pressure, increased secretion by salivary and digestive glands, increased motility and blood flow in the digestive tract, and stimulation of urination and defecation.
Compare the anatomy of the sympathetic division with that of the parasympathetic division.
>in the sympathetic division, axons emerge from a thoracic and lumbar segments of the signal cord and innervate ganglia relatively close to the spinal cord. >in the parasympathetic division, axons emerge from the brainstem and sacral segments of the spinal cord and innervate ganglia very close to (or within) target organs.
Define baroreceptors. Where are baroreceptors located within the body?
>stretch receptors that monitor changes in pressure. >they are located along the digestive tract (stomach intestines, and colon), within the walls of the urinary bladder, in the carotid and aortic sinuses, and in the lungs.
what neurotransmitter is released by all parasympathetic neurons?
Acetylcholine (ACh)
in the ___, the ganglia are close to the spinal cord.
SNS
which neurotransmitter is released by all preganglionic fibers of the autonomic nervous sytem?
acetylcholine
what are the two types of adrenergic receptors?
alpha and beta
define visceral reflex.
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.
why is the parasympathetic division called 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.*
if your heart rate is too fast or it beats too hard, what meds might you be prescribed?
beta blockers
which receptors would you block to decrease heart rate?
beta receptors
a person with high blood pressure (hypertension) is prescribed a drug that blocks beta receptors. how could this medication alleviate hypertension?
blocking the beta receptors on cardiac cells would decrease (or prevent) sympathetic stimulation of tissues containing those cells. as a result, heart rate, force of cardiac muscle contraction, and contraction of the smooth muscle in blood vessel walls would decrease, lowering blood pressure
_____: organs receive input from both the SNS and PNS of the ANS.
dual innervation
define dual innervation.
means that a given body structure receives instructions from both the sympathetic and parasympathetic divisions of the ANS
which division of the nervous system contains the vagus nerve?
parasympathetic
dual innervation refers to situations in which vital organs ___.
receive information from both sympathetic and parasympathetic fibers
explain the significance of the ANS to homeostasis.
the ANS adjusts the activities of virtually every body system, maintaining homeostasis without instructions or interference from the conscious mind
you go outside on a cold day, and blood flow to your skin is reduced, conserving body heat. you become angry, and your face turns red. explain these changes.
the blood vessels of the skin receive only sympathetic innervation. when you go outside into the cold, sympathetic neurons release NE and cause vasoconstriction of superficial blood vessels through stimulation of alpha receptors. when you get angry, sympathetic activation occurs, and large amounts of epinephrine enter the circulation. this stimulates beta receptors in the superficial blood vessels, dilating those vessels, and stimulates the heart, increasing blood pressure and blood flow. as a result, your skin--and most obviously your face--turns red.
which division of the ANS is responsible for the physiological changed you experience when startled by a loud noise?
the sympathetic division of the ANS is responsible or the physiological changes that occur when you are startled by a loud noise.
the autonomic nervous system directs ___.
unconscious processes that maintain homeostasis