Chapter 3 Flashcards by Lovely jane Luchavez

sends signals to target tissues by varying the levels of blood-
borne hormones.

a. autonomic nervous system
b. endocrine system

answer: b. endocrine system

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exerts effects by the
rapid transmission of electrical impulses over nerve fibers that terminate
at effector cells, which specifically respond to the release of neuromedia-
tor substances

a. nervous system
b. endocrine system

answer: a. nervous system

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Drugs that produce their primary therapeutic effect by
mimicking or altering the functions of the ANS are called

a. autonomic nervous system
b. endocrine system

answer: a. autonomic nervous system

note:. The autonomic agents
act either by stimulating portions of the ANS or by blocking the action of
the autonomic nerves.

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nervous system is divided into two anatomical divisions:

answer: the central
nervous system (CNS), peripheral nervous system,

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composed of the brain and spinal cord

a. the central
nervous system (CNS)

b. peripheral nervous system

answer:a. the central
nervous system (CNS)

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includes neurons located out-
side the brain and spinal cord-that is, any nerves that enter or leave the
CNS

a. the central
nervous system (CNS)

b. peripheral nervous system

answer: b. peripheral nervous system

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The peripheral nervous system is subdivided into

answer:the
efferent and afferent divisions.

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carry signals away
from the brain and spinal cord to the peripheral tissues,

a.
efferent division
b. afferent divisions

answer: a.
efferent division

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bring information from the periphery to the CNS.

a.
efferent division
b. afferent divisions

answer: b. afferent divisions
note: Afferent neu-rons provide sensory input to modulate the function of the efferent divi-
sion through reflex arcs or neural pathways that mediate a reflex action.

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memo the Figure 3.1
Organization of the nervous system.

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are
involved in the voluntary control of functions such as contraction of
the skeletal muscles essential for locomotion.

a.autonomic efferent system
b. somatic efferent system

answer: b. somatic efferent system

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it is also known as the
visceral, vegetative, or involuntary nervous system.

a.autonomic nervous system
b. somatic efferent system

answer: a.autonomic nervous system

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innervate visceral smooth muscle, cardiac mus-
cle, vasculature, and the exocrine glands, thereby controlling diges-
tion, cardiac output, blood flow, and glandular secretions.

a. afferent neurons
b. efferent neurons

answer: b. efferent neurons

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ANS carries nerve impulses from the
CNS to the effector organs through two types of efferent neu-
rons:

answer: preganglionic neurons and the postganglionic neurons

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primary nerve cell

a.preganglionic neurons
b. the postganglionic neurons

answer: a.preganglionic neurons

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secondary nerve cell

a.preganglionic neurons
b. the postganglionic neurons

answer: b. the postganglionic neurons

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(fibers) of the ANS are
important in the reflex regulation of this system {for example, by sens-
ing pressure in the carotid sinus and aortic arch) and in signaling the
CNS to influence the efferent branch of the system to respond.

a. afferent neuron
b. efferent neuron

answer: a. afferent neuron

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The
preganglionic neurons of the sympathetic system come from the
_______ and ______, (__ to __) of the spinal cord

answer: The
preganglionic neurons of the sympathetic system come from the
thoracic and lumbar regions (T1 to L2) of the spinal cord

note:The preganglionic neu-
rons are short in comparison to the postganglionic ones.

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The adrenal medulla, in
response to stimulation by the ganglionic neurotransmitter ______

answer: The adrenal medulla, in
response to stimulation by the ganglionic neurotransmitter acetyl-
choline, secretes epinephrine (adrenaline), and lesser amounts of
norepinephrine, directly into the blood.]

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The parasympathetic pregangli-
onic fibers arise from cranial nerve:

answer: cranial nerves Ill (oculomotor), VII (facial),
IX (glossopharyngeal), and X (vagus), as well as from the sacral
region (S2 to S4) of the spinal cord

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sympathetic system, the pregangli-
onic fibers are ___, and the postganglionic ones are ___,

answer: sympathetic system, the pregangli-
onic fibers are long, and the postganglionic ones are short

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It is a collection of nerve fibers that innervate the
gastrointestinal (GI) tract, pancreas, and gallbladder, and it consti-
tutes the “brain of the gut.”

a. sympathetic neuron

b. parasumpathetic neiron

c. enteric neuron

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This system functions independently of
the CNS and controls motility, exocrine and endocrine secretions,
and microcirculation of the Gl tract

a. sympathetic neuron

b. parasumpathetic neiron

a. sympathetic neuron

b. parasumpathetic neiron

c. enteric neuron

note: It is modulated by both the
sympathetic and parasympathetic nervous systems.

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It is required for life, since it maintains essential
bodily functions, such as digestion and elimination.

a. sympathetic nervous

b. parasympathetic nervous

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"Fight-or-flight" stimulus a. sympathetic output b. parasympathetic output

a. sympathetic output note:(diffuse because postganglionic neurons may innervate more than one organ)

Rest-and-digestn stimulus a. sympathetic output b. parasympathetic output

b. parasympathetic output note:(discrete because postganglionic neurons are not branched, but are directed to a specific organ)

increase in heart rate and blood pressure, mobilization of energy stores, and increase in blood flow to skeletal muscles and the heart while diverting flow from the skin and internal organs. a. sympathetic b. parasympathetic

a. sympathetic

stimulation of this may result in dilation of the pupils and bronchioles a. sympathetic b. parasympathetic

a. sympathetic

what hormone does adrenal medulla release?

epinephrine and less norepinephrine

it maintains essential bodily functions, such as digestion and elimination a. sympathetic b. parasympathetic

b. parasympathetic note:. The parasympa- thetic division usually acts to oppose or balance the actions of the sympathetic division and generally predominates the sympathetic system in "rest-and-digest" situations. Unlike the sympathetic system, the parasympathetic system never discharges as a complete system

slow heart rate a. sympathetic b. parasympathetic

b. parasympathetic

fast heart rate a. sympathetic b. parasympathetic

a. sympathetic

what nerve is the predominant factor for controlling heart rate?

vagus nerve

note:adrenal medulla, kidney, pilomotor muscles, and sweat glands, receive innervation only from the sympathetic system.

nervous system differs from the ANS in that a single myelinated motor neuron, originating in the CNS, travels directly to skeletal muscle without the mediation of ganglia. a. somatic b. ANS

a. somatic

voluntary control a. somatic b. ANS

a. somatic

involuntary control a. somatic b. ANS

b. ANS note:Responses in the somatic division are generally faster than those in the ANS.

site of origin :Thoracic and lumbar region of the spinal cord (thoracolumbar) a. sympathetic b. parasympathetic

a. sympathetic

site of origin:Brain and sacral area of the spinal cord (craniosacral) a. sympathetic b. parasympathetic

b. parasympathetic

sympathetic length of fiber: preganglionic: post ganglionic:

sympathetic length of fiber: preganglionic:short post ganglionic:long

parasympathetic length of fiber: preganglionic: post ganglionic:

parasympathetic length of fiber: preganglionic:long post ganglionic: short

location of ganglia : close to the spinal cord a. sympathetic b. parasympathetic

a. sympathetic

location of ganglia : within or near the effector organs a. sympathetic b. parasympathetic

b. parasympathetic

Preganglionic fiber branching: extensive a. sympathetic b. parasympathetic

a. sympathetic

Preganglionic fiber branching: minimal a. sympathetic b. parasympathetic

b. parasympathetic

Distribution: wide a. sympathetic b. parasympathetic

a. sympathetic

Distribution: limited a. sympathetic b. parasympathetic

b. parasympathetic

types of response: Diffuse a. sympathetic b. parasympathetic

a. sympathetic

types of response: Discrete a. sympathetic b. parasympathetic

b. parasympathetic

innervates skeletal muscles. a. ANS b. somatic nervous system

b. somatic nervous system

Most cells secrete chemicals that act locally on cells in the immediate environment. Because these chemical signals are rapidly destroyed or removed, they do not enter the blood and are not distributed throughout the body a. hormone b. local mediator c. neurotransmitter

b. local mediator

histamine a. hormone b. local mediator c. neurotransmitter

b. local mediator

prostaglandin a. hormone b. local mediator c. neurotransmitter

b. local mediator

Neurotransmitters Communication between nerve cells, and between nerve cells and effector organs, occurs through the release of specific chemical sig- nals {neurotransmitters) from the nerve terminals. The release is triggered by arrival of the ____at the nerve ending, leading to ______. An increase in intracellular _____ initiates fusion of synaptic vesicles with the presynaptic membrane and release of their contents. The neurotransmitters rapidly diffuse across the synaptic cleft, or space (synapse), between neurons and combine with specific receptors on the postsynaptic (target) cell.

Neurotransmitters Communication between nerve cells, and between nerve cells and effector organs, occurs through the release of specific chemical sig- nals {neurotransmitters) from the nerve terminals. The release is triggered by arrival of the action potential at the nerve ending, leading to depolarization. An increase in intracellular Ca2+ initiates fusion of synaptic vesicles with the presynaptic membrane and release of their contents. The neurotransmitters rapidly diffuse across the synaptic cleft, or space (synapse), between neurons and combine with specific receptors on the postsynaptic (target) cell.

note:All neurotransmitters, and most hormones and local mediators, are too hydrophilic to penetrate the lipid bilay- ers of target cell plasma membranes. Instead, their signal is medi- ated by binding to specific receptors on the cell surface of target organs. Most receptors are proteins

cholinergic neuron releases ___ a. acetylcholine b. norepinephrine

a. acetylcholine

adrenergic neuron releases __ a. acetylcholine b. norepinephrine

b. norepinephrine

what is released by adrenal medulla a. acetylcholine b. epinephrine c.norepinephrine

b. epinephrine

has no ganglia a. autonomic nervous system b. somatic nervous system

b. somatic nervous system

what pre ganglionic receptor will acetylcholine blind a. nicotinic receptor b. adrenergic receptor c. muscarinic receptor

a. nicotinic receptor

what sympathetic post ganglionic will release a. norepinephrine b. acetylcholine

a. norepinephrine

what parasympathetic post ganglionic will release a. norepinephrine b. acetylcholine

b. acetylcholine

what postganglionic receptor will acetylcholine blind a. nicotinic receptor b. adrenergic receptor c. muscarinic receptor

c. muscarinic receptor

where will postganglionic receptor epinephrine blind a. nicotinic receptor b. adrenergic receptor c. muscarinic receptor

b. adrenergic receptor

where will postganglionic receptor norepinephrine blind a. nicotinic receptor b. adrenergic receptor c. muscarinic receptor

b. adrenergic receptor

are the primary chemical signals in the ANS,

Acetylcholine and norepinephrine

Receptors coupled to lon channels a. lonotroplc receptors b.metabotropic receptors

a. lonotroplc receptors

Receptors coupled to adenylyl cyclase a. lonotroplc receptors b.metabotropic receptors

b.metabotropic receptors

Receptors coupled to diacylglycerol and inositol trisphosphate a. lonotroplc receptors b.metabotropic receptors

b.metabotropic receptors

note:All adrenergic receptors and cholinergic muscarinic receptors are G protein-coupled receptors (metabotropic receptors).

Which is correct regarding the sympathetic nervous system? A. It generally mediates body functions in "rest-and- digesr mode. B. The neurotransmitter at the sympathetic ganglion is norepinephrine (NE). C. The neurotransmitter at the sympathetic ganglion is acetylcholine (ACh). D. Sympathetic neurons release ACh in the effector organs.

Correct answer = C. The neurotransmitter at the sympa- thetic and parasympathetic ganglia Is acetylcholine. The sympathetic system generally mediates body functions In "fight or flight" mode, and the parasympathetic system gen- erally mediates body functions in "rest-and-digesf' mode. Sympathetic neurons release NE, and parasympathetic neurons release ACh in the effector cells.

Why does the somatic nervous system enable a faster response compared to the ANS? A. Somatic motor neurons have ganglia where neuro- transmission is mediated by ACh. B. Somatic motor neurons have ganglia where neuro- transmission is mediated by NE. C. Somatic motor neurons are not myelinated. D. Somatic motor neurons are myelinated and do not have ganglia.

Correct answer= D. Somatic motor neurons are myelinated and have no ganglia. This enables faster transmission in the somatic neurons.

Which physiological change occurs when the parasym- pathetic system is activated? A. Increase in heart rate B. Inhibition of lacrimation (tears) C. Dilation of the pupil (mydriasis) D. Increase in gastric motility

Correct answer = D. Activation of the parasympathetic sys- tem causes an increase in gastric motility, increase in fluid secretions, reduction In heart rate, and constriction of the pupil. In the "rest-and-dlgesr mode, the parasympathetic system Is more active, which helps with digestion.

Which physiological change is expected when the sym- pathetic system is inhibited using a pharmacological agent? A. Reduction in heart rate B. Increase in blood pressure C. Decrease in fluid secretions D. Constriction of blood vessels

Correct answer = A. Activation of the sympathetic sys- tem causes an increase in heart rate, increase in blood pressure, reduction or thickening of fluid secretions, and constriction of blood vessels. Therefore, Inhibition of the sympathetic system should theoretically cause a reduction in heart rate, decrease in blood pressure, Increase in fluid secretions, and relaxation of blood vessels.

Which is correct regarding activation of receptors on the effector organs in the ANS? A. Acetylcholine activates muscarinic receptors. B. Acetylcholine activates adrenergic receptors. C. Epinephrine activates nicotinic receptors. D. Norepinephrine activates muscarinic receptors.

Correct answer = A. Acetylcholine Is the neurotransmitter in the cholinergic system, and it activates both muscarinic and nicotinic cholinergic receptors, not adrenergic recep- tors. Norepinephrine and epinephrine activate adrenergic receptors, not muscarinic receptors.

Which statement concerning the parasympathetic ner- vous system is correct? A. The parasympathetic system often discharges as a single, functional system. B. The parasympathetic division is involved in near vision, movement of food, and urination. C. The postganglionic fibers of the parasympathetic division are long, compared to those of the sympa- thetic nervous system. D. The parasympathetic system controls the secretion of the adrenal medulla.

Correct answer = B. The parasympathetic nervous sys- tem maintains essential bodily functions, such as vision, movement of food, and urination. It uses acetylcholine, not norepinephrine, as a neurotransmitter, and it discharges as discrete fibers that are activated separately. The post- ganglionic fibers of the parasympathetic system are short compared to those of the sympathetic division. The adrenal medulla Is under the control of the sympathetic system.

Which is correct regarding neurotransmitters and neu rotransm ission? A. Neurotransmitters are released from the presynaptic nerve terminals. B. Arrival of an action potential in the postsynaptic cell triggers release of neurotransmitter. C. Intracellular calcium levels drop in the neuron before the release of neurotransmitter. D. Serotonin and dopamine are the primary neurotrans- mitters in the ANS.

Correct answer = A. Neurotransmitters are released from presynaptic neurons, triggered by the arrival of an action potential In the presynaptic neuron (not in the postsynap- tic cell). When an action potential arrives in the presynaptic neuron, calcium enters the presynaptic neuron and calcium levels increase in the neuron before neurotransmitter is released. The main neurotransmitters in the ANS are nor- epinephrine and acetylcholine.

An elderly man is brought to the emergency room after ingesting a large quantity of prazosin tablets, a drug that blocks a1 adrenergic receptors, which mediate effects of epinephrine and norepinephrine on the blood vessels and urinary bladder. Which symptom is most likely to be seen in this patient? A. Reduced heart rate (bradycardia) B. Dilation of blood vessels (vasorelaxation) C. Increased blood pressure D. Reduction in urinary frequency

Correct answer = B. Activation of a., receptors causes vaso- constriction, reduction In urinary frequency, and an Increase in blood pressure, without a direct effect on the heart rate. It may cause reflex tachycardia (increase in heart rate) in some patients. Thus blockade of a., receptors could theo- retically cause dilation of blood vessels, reduction in blood pressure, and increase in urinary frequency. It should not cause a reduction in heart rate.

Which statement is correct regarding the autonomic nervous system? A. Afferent neurons carry impulses from the central nervous system (CNS) to the effector organs. B. Preganglionic neurons of the sympathetic system arise from the cranial nerves, as well as from the sacral region. C. When there is a sudden drop in blood pressure, the baroreceptors send signals to the brain to activate the parasympathetic system. D. The heart receives both sympathetic and parasym- pathetic innervation.

Correct answer = D. The heart receives both sympathetic and parasympathetic innervation. Activation of sympathetic neurons increases the heart rate and force of contrac- tion, and activation of parasympathetic neurons reduces the heart rate and force of contraction (slightly). Afferent neurons carry Impulses from the periphery to the CNS, and efferent neurons carry signals away from the CNS. Preganglionic neurons of the sympathetic system arise from thoracic and lumbar regions of the spinal cord, whereas the preganglionic neurons of the parasympathetic system arise from cranial nerves and the sacral region. When there is a sudden drop In blood pressure, the sympathetic system Is activated, not the parasympathetic system.

Which is correct regarding membrane receptors and signal transduction? A. ANS neurotransmitters bind to membrane recep- tors on the effector cells, which leads to intracellular events. B. Cholinergic muscarinic receptors are ionotropic receptors. C. Cholinergic nicotinic receptors are metabotropic receptors. D. Metabotropic receptors activate ion channels directly.

Correct answer = A. Neurotransmitters generally bind to membrane receptors on the postsynaptic effector cells and cause cellular effects. Acetylcholine (ACh) binds to choliner- gic muscarinic receptors and activates the second messen- ger pathway in effector cells, which in turn causes cellular events. Receptors that are coupled to second messenger systems are known as metabotropic receptors. Metabotropic receptors do not directly activate ion channels. ACh also binds to cholinergic nicotinic receptors and activates ion channels on the effector cells. The receptors that directly activate ion channels are known as lonotroplc receptors.