Anatomy

Sympathetic division thoraco-lumbar division of ANS Sympathetic chain ganglia

1. 2 chains of ganglia - one on each side of the vertebral column 2. cervical chain ganglia are fused into superior, middle, and inferior 3. innervate head, body wall, limbs, and viscera of thoracic cavity (heart, lungs)

Structure of the ANS Efferent pathway is two neuron pathway

1. Motor neurons in CNS send axons (preganglionic) to synapse on motor neurons in autonomic ganglia in PNS 2. Motor neurons in autonomic ganglia (ganglionc cells) send axons (postganglionic axons) to synapse on effector

Sympathetic division thoraco-lumbar division of ANS adrenal medulla

1. central portion of the adrenal gland 2. preganglionic fibers in anterior root, white ramus, then pass through chain ganglia and splanchnic nerve to superior messenteric ganglia, pass through to reach adrenal gland 3. Postganglionic cells in adrenal medulla are modified neurons that secrete in blood rather than onto effector

Parasympathetic activation

1. has localized effect 2. innervation limited to head and viscera, does not innervate body wall, skin 3. each preganglionic axon branches to synapse on to only 6-8 ganglionic cells 4. postganglionic axons generally go to a single effector

Sympathetic division thoraco-lumbar division of ANS collateral ganglia

1. located close to large abdominal arteries 2. celiac, superior mesenteric, inferior mesenteric ganglia 3. Preganglionic fibers in anterior root, white ramus, then pass through chain ganglia and form splanchnic nerves to reach collateral ganglia 4. Innervate abdominal and pelvic viscera. (sympathetic activation decreases blood flow and releases stored energy molecules)

sympathetic activation has wide spread effect on body due to

1. sympathetic innervation is throughout the body 2. each preganglionc axon branches to synapse onto 24 or more ganglionic cells 3. adrenal medulla releases epinephrine and norepinephrine into blood stream, affecting tissues not innervated by ANS

Dual innervation refers to situations in which a. vital organs receive instructions from both sympathetic and parasympathetic fibers b. the atria and ventricles of the heart receive autonomic stimulation from the same nerves c. sympathetic and parasympathetic fibers have similar effects d. a, b, and c are correct

A

the division of the autonomic nervous system that prepares the body for activity and stress is the _____ division a. sympathetic b. parasympathetic c. craniosacral d. intramural e. somatomotor

A

Luke has a brain tumor that is interfering with the function of his hypothalamus. Would you expect this tumor to interfere with autonomic function? Why or why not?

A brain tumor that interferes with hypothalamic function would also interfere with autonomic function. Centers in the posterior and lateral hypothalamus coordinate and regulate sympathetic function, whereas centers in the anterior and medial hypothalamus control parasympathetic function.

Define visceral reflex.

A visceral reflex is an automatic motor response that can be modified, facilitated or inhibited by higher centers, especially those of the hypothalamus.

What neurotransmitter is released by all parasympathetic neurons?

Acetylcholine (ACh) is the neurotransmitter released by all parasympathetic neurons.

Effects produced by the parasympathetic branch of the autonomic nervous system include a. dilation of the pupils b. increased secretion by digestive glands c. dilation of respiratory passages d. increased heart rate e. increased breakdown of glycogen by the liver

B

Under which of the following circumstances would the diameter of peripheral blood vessels be greatest? a. increased sympathetic stimulation b. decreased sympathetic stimulation c. increased parasympathetic stimulation d. decreased parasympathetic stimulation e. both increased parasympathetic and sympathetic stimulation

B

How would a drug that stimulates acetylcholine receptors affect the sympathetic nervous system?

Because preganglionic fibers of the sympathetic nervous system release acetylchoine (ACh) a drug that stimulates ACh receptors would stimulate the postganglionic fibers of sympathetic nerves resulting in increased sympathetic activity.

An individual with high blood pressure is given a medication that blocks beta receptors. How could this medication help correct that person's condition?

Blocking the beta receptors on cells would decrease or prevent sympathetic stimulation of tissues containing those cells. Heart rate, force of contraction of cardiac muscle, and contraction of smooth muscle in the walls of blood vessels would decrease, lowering blood pressure.

All preganglionic autonomic fibers release ____ at their synaptic terminals and the effects are always ____. a. norepinephrine; inhibitory b. norepinephrine; excitatory c. acetylcholine; excitatory d. acetylcholine; inhibitory

C

During sympathetic stimulation a person may begin to fill "on edge" this is a result of a. increased energy metabolism by muscle tissue b. increased cardiovascular activity c. stimulation of the reticular activating system d. temporary insensitivity to painful stimuli e. decreased levels of epinephrine in the blood

C

Which of the following is true? A. somatic motor system controls skeletal muscles B. autonomic motor system controls visceral muscles C. Both A and B are true

C

Nicotine stimulates cholinergic receptors of the autonomic nervous system. Based on this information how would cigarette smoking affect the cardiovascular system?

Cholinergic receptors are found in all of the ganglia of the ANS, so nicotine would stimulate both sympathetic and parasympathetic responses in cardiovascular tissues. Although increased sympathetic stimulation increases heart rate and force of contraction, increased parasympathetic stimulation simultaneously decreases blood flow to the heart muscle. In addition to elevating heart rate and force of contraction, sympathetic stimulation also constricts peripheral blood vessels, all of which contribute to increased blood pressure.

A possible side effect of a drug used to open the airways of someone suffering from an asthma attack is a. decreased activity of the digestive system b. diarrhea c. profuse urination d. increased blood pressure e. decreased heart rate

D

The neurotransmitter at all synapses and neuromuscular or neuroglandular junctions in the parasympathetic division of the ANS is a. epinephrine b. norepinephrine c. cyclic-AMP d. acetylcholine

D

the autonomic division of the nervous system directs a. voluntary motor activity b. conscious control of skeletal muscles c. unconscious control of skeletal muscles d. processes that maintain homeostasis e. sensory input from the skin

D

You are home alone at night when you hear what sounds like breaking glass. What physiological effects would this experience probably produce and what would be their cause?

Due to the stimulation of the sympathetic division you would experience increased respiratory rate, increased peripheral vasoconstriction and elevation of blood pressure, increased heart rate and force of contraction and an increased rate of glucose release into the bloodstream.

what are the components of a visceral reflex arc?

Each visceral reflex arc consists of a receptor a sensory neuron, a processing center (one or more interneurons), and two visceral motor neurons. All visceral reflexes are polysynaptic. They can be long reflexes or short reflexes.

Phil is stung on his cheek by a wasp. Because Phil is allergic to wasp venom, his throat begins to swell and his respiratory passages constrict. Would acetylcholine or epinephrine be more helpful in relieving his condition? Why?

Epinephrine would be more effective, because it would reduce inflammation and relax the smooth muscle of the airways, making it easier for Phil to breathe.

Why is autonomic tone a significant part of ANS function?

If autonomic motor neurons maintain a background level of activity at all times they can either increase or decrease their activity providing a greater range of control options.

What physiological changes would you expect in a patient who is about to undergo a dental root canal and is quite anxious about the procedure?

In anxious individuals, and increase in sympathetic stimulation would probably cause some or all of the following changes: a dry mouth; increased heart rate, blood pressure, and rate of breathing cold sweats; and urge to urinate or defecate; a change in the motility of the digestive tract (that is, "Butterflies in the stomach") and dilated pupils.

What effect would the loss of sympathetic tone have on blood flow to a tissue?

Most blood vessels receive sympathetic stimulation, so a loss of sympathetic tone would relax the smooth muscles lining the vessels; resulting vasodilation would increase blood flow to the tissue.

How would the stimulation of muscarinic receptors in cardiac muscle affect the heart?

Stimulation of muscarinic receptors a type of acetylcholine receptor located in postganglionic synapses of the parasympathetic nervous system would cause K+ channels to open resulting in hyperpolarization of cardiac plasma membranes and decreased heart rate.

Differences between structure of sympathetic and parasympathetic

Sympathetic (thoraco-lumbar division) Parasypmathetic (cranio-sacral division)

Organization and anatomy of the sympathetic division which SC segment _______ ventral roots contain preganglionic axons.

T1-L2

While studying the activity of smooth muscle in blood vessels, Shelly discovers that when applied to a muscle plasma membrane, a molecule chemically similar to a neurotransmitter triggers an increase in intracellular calcium ions. Which neurotransmitter is the molecule mimicking and to which receptors is it binding?

The molecule is probably mimicking NE and binding to alpha-1 receptors.

Why is the parasympathetic division sometimes referred to as the anabolic system?

The parasympathetic division is sometimes referred to as 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.

Why does sympathetic function remain intact even when the ventral roots of the cervical spinal nerves are damaged?

The preganglionic fibers innervating the cervical ganglia originate in the ventral roots of the thoracic segments, which are undamaged.

While out for a walk, Julie suddenly meets an angry dog. Which division of the autonomic nervous system is responsible for the physiological changes that occur in Julie as she turns and runs?

The sympathetic division of the ANS is responsible for the physiological changes that occur in response to stress (confronting an angry dog) and increased activity (running).

On the basis of anatomy, how could you distinguish the sympathetic division from the parasympathetic division of the ANS?

The sympathetic division of the autonomic nervous system includes preganglionic fibers from the lumbar and thoracic portions of the spinal cord, whereas the parasympathetic division includes preganglionic fibers from the cranial and sacral portions.

Identify the two major divisions of the autonomic nervous system.

The two major divisions of the autonomic nervous system are the sympathetic division and the parasympathetic division.

Name the two types of ACh receptors on the postsynaptic membranes of parasympathetic neurons.

The two type of ACh receptors on the postsynaptic membranes of parasympathetic neurons are nicotinic receptors and muscarinic receptors.

The condition known as shock is characterized in part by a decreased return of venous blood to the heart. How could an upsetting situation, such as the sight of a tragic accident or very bad news, produce some temporary symptoms of shock?

The upsetting stimuli would be processed by higher centers of the CNS and relayed to the hypothalamus. The hypothalamus could suppress the vasomotor center of the medulla oblongata, resulting in fewer sympathetic impulses to peripheral blood vessels. This would cause a decrease in sympathetic tone in the smooth muscle of the blood vessels resulting in vasodilation. The vasodilation would cause blood to pool in the limbs decreasing the amount of blood returning to the hear and producing shock

Which nerve is responsible for the parasympathetic innervation of the lungs, heart, stomach, liver, pancreas, and parts of the small and large intestines?

The vagus nerve (NX) carries preganglionic parasympathetic fibers that innervate the lungs, heart, stomach, liver, pancreas, and parts of the small and large intestines (as well as several other visceral organs).

How many motor neurons are needed to carry an action potential from the spinal cord to smooth muscles in the wall of the intestine?

Two neurons are needed to carry an action potential from the spinal cord to smooth muscles in the intestine. The first neuron carries the action potential from the spinal cord to the autonomic ganglion, and a second neuron carries the action potential from the autonomic ganglion to the smooth muscle.

synapse of postganglionic axon to effector

all parasympathetic postganglionic axons release Ach onto effectors sympathetic postganglionic axons to dual innervated viscera release NE onto effectors

Drugs used to treat hypertension (low blood pressure) by stimulating alpha 1 receptors to cause vasoconstriction of blood vessels

alpha1-receptor agonists

Drugs used to treat hypertension (high blood pressure) by stimulating alpha 2 adrenergic receptors to inhibit sympathetic vasomotor centers.

alpha2-receptors agonists

this system coordinated processes that maintain homeostasis

autonomic nervous system

this system is regulated by higher brain centers that affect the hypothalamus

autonomic nervous system

what system controls smooth muscles, cardiac muscles, glands

autonomic nervous system

what system operates without conscious control via reflex centers in spinal cord and brainstem controlled by hypothalamus.

autonomic nervous system

Drugs that decrease heart rate and force of contraction, lowering peripheral blood pressure by acting on beta adrenergic receptors to diminish the effects of epinephrine

beta-adrenergic blockers

organization and anatomy of the sympathetic division some axons synapse on cells of __________________

chain ganglia

the symapathetic division is a result of

change in our body under stress

organization and anatomy and sympathetic division some axons pass through going to _____ and adrenal medulla

collateral ganglia

describe parasympathetic division

conserve and restore body energy, rest and recovery dominant control during rest

Effectors with single innervation (sympathetic input) blood vessels of digestive viscera and kidney have

constriction

Effectors with single innervation (sympathetic input) arrector pili muscles have

contraction

which nerve has parasympathetic control of pupil and lens

cranial nerve III oculomotor

which nerve has salivary glands

cranial nerve IX glossopharyngeal

which nerve has lacrimal and salivary glands

cranial nerve VII facial

Effectors with dual innervation digestive tract - sympathetic _____ motility and secretions, parasympathetic ____

decreases, increases

synapse of postganglionic axon to effector

different neurotransmitters and postsynaptic receptors depending on synapse

Effectors with dual innervation bronchioles - sympathetic ____ airways, parasympathetic ________ airways

dilates, constricts

Effectors with dual innervation pupils - sympathetic ___ pupils, parasympathetic ____ pupils

dilates, constricts

Effectors with single innervation (sympathetic input) blood vessels of skin, skeletal muscle, heart, lungs brain have

dilation

Under which set of circumstances would heart rate be fastest? a. increased sympathetic stimulation b. decreased sympathetic stimulation c. increased parasympathetic stimulation d. decreased parasympathetic stimulation e. increase sympathetic stimulation decreased parasympathetic

e

Describe sympathetic division

expenditure of energy dominant under condition of physical or emotional stress (flight or fight response)

the autonomic system is involved with

homeostasis

Effectors with dual innervation heart - sympathetic ___ heart rate, parasympathetic ____ heart rate

increase, decrease

Effectors with single innervation (sympathetic input) sweat glands have

increased secretion

Effectors with parasympathetic input only are

lacrimal glands (increased secretion)

synapse of preganglionic axon onto cell in autonomic ganglion

neurotransmitter is ACh in both sympathetic and parasympathetic ganglia

synapse of preganglionic axon onto cell in autonomic ganglion

neurotransmitter is acetyl choline (ACh) postsynaptic receptor is nicotinic cholinergic same in sympathetic and parasympathetic ganglia

Division of the autonomic nervous system that prepares the body for rest is the

parasympathetic also known as parisacrial

Drugs that target the muscarinic receptors at neuromuscular or neuroglandular junctions

parasympathetic blocking agents

Drugs that mimic parasympathetic stimulation and increase the activity along the digestive tract

parasympathomimetic drugs

spinal cord segment S2, S3, S4

pelvic nerves carry preganglionic axons to parasympathetic intramural ganglia located in wall of viscera in inferior portion of abdominal pelvic cavity short postganglionic axon innervate effectors

____ receptor properties determines effect of neurotransmitter on postsynaptic cell

postsynaptic

the parasumpathetic division is a result of

relaxed everything is great

Nicotinic cholinergic receptors

skeletal muscles, autonomic ganglia excitatory

what system controls the skeletal muscles

somatic nervous system

Division of the autonomic nervous system that prepares the body for activity and stress is the

sympathetic also known as thoracolumbar

autonomic activation

sympathetic and parasympathetic divisions are activated by different stimuli

Drugs that bind to receptor sites preventing a normal response to neurotransmitters or sympathomometic drugs

sympathetic blocking agents

drugs that mimic the effects of sympathetic stimulation

sympathomimetic drugs

the peripheral nervous system control what

the afferent sensory system (general and special senses)

the central nervous system consist of

the brain and spinal cord

there are two divisions of the Autonomic nervous system what are they

the sympathetic division and the parasympathetic division

which nerve carries 75% of all parasympathetic output

vagus nerve X

which nerve has parsympathetic control of heart, lungs, digestive tract and all other thoracic and abdominal viscera, except most inferior portions

vagus nerve X

muscarinic cholinergic receptors

visceral muscles, cardiac muscle, CNS

organization and anatomy of the sympathetic division _________ from ventral root carries axons to sympathetic chain ganglia.

white ramus branch