Chapter 10: Autonomic and Somatic Nervous System

All five subtypes of muscarinic acetylcholine receptors are ___-__________ __________ receptors or also known as __________

G protein-coupled; metabotropic

The ___________, _________ _______, and _______ ______ contain centers that control autonomic activities.

hypothalamus, brain stem, and spinal cord

Somatic Nervous System: A skeletal muscle fiber has only one NMJ and it is usually located near the _________ of the fiber.

midpoint

The parasympathetic nervous system enhances _____-____-______ activities

rest-and-digest

The axons form tracts from the hypothalamus to parasympathetic and sympathetic nuclei in the brain stem and spinal cord through relays in the _________ _______.

reticular formation

Neurons of the _____________ nervous system increase heart rate, and neurons of the _______________ nervous system slow it down.

sympathetic; parasympathetic

An autonomic motor pathway consists of what two autonomic motor neurons in series?

1. A preganglionic neuron 2. A postganglionic neuron

The preganglionic neurons convey action potentials from the _________ __________ __________ to _________ __________. The postganglionic neurons relay the action potentials from ___________ ___________ to _________ __________.

Central Nervous System; autonomic ganglia; autonomic ganglia; visceral effectors

What does dual innervation mean?

Dual innervation means that an organ receives neural innervation from both the parasympathetic and sympathetic branches of the ANS.

Both subtypes of nicotinic ACh receptors are ____________ receptors that contain two binding sites for acetylcholine and a cation channel.

Ionotropic

True or False The Enteric Nervous System contains sensory neurons, interneurons, and motor neurons.

True

There are _____ subtypes of nicotinic acetylcholine receptors and _______ subtypes of muscarinic acetylcholine receptors.

Two (N1 and N2); Five (M1 through M5)

Cholinergic neurons release _____________; adrenergic neurons release ________________.

acetylcholine (ACh); norepinephrine (NE)

Adrenergic neurons release norepinephrine (NE), also known as ___________

noradrenaline

Enteric _________ neurons monitor chemical changes within the GI tract as well as the stretching of its walls. Enteric __________ integrate information from the sensory neurons and provide input to motor neurons. Enteric __________ neurons govern contraction of GI tract smooth muscle and secretion of GI tract glands.

sensory; interneurons; motor

The effects of sympathetic stimulation are longer lasting and more widespread than the effects of parasympathetic stimulation for three reasons?

1. Sympathetic postganglionic axons diverge more extensively; as a result, many tissues are activated simultaneously. 2. Acetylcholinesterase quickly inactivates acetylcholine, but nor-epinephrine lingers in the synaptic cleft for a longer period. 3. Epinephrine and norepinephrine secreted into the blood from the adrenal medulla intensify and prolong the responses caused by norepinephrine liberated from sympathetic postganglionic axons. These blood-borne hormones circulate throughout the body, affecting all tissues that have alpha and beta receptors. In time, blood-borne norepinephrine and epinephrine are inactivated by enzymatic destruction in the liver.

What are the effects of the fight-or-flight response?

1. The diameter of the pupils increases (pupillary dilation). 2. Heart rate, force of heart contraction, and blood pressure increase. 3. The diameter of the bronchial tubes increases (bronchodilation), allowing faster movement of air into and out of the lungs. 4. The blood vessels that supply the kidneys and gastrointestinal tract constrict, which decreases blood flow through these tissues. The result is a slowing of urine formation and digestive activities, which are not essential during emergency situations. 5. Blood vessels that supply organs involved in exercise or fighting off danger—skeletal muscles, cardiac muscle, liver, and adipose tissue—dilate, allowing greater blood flow through these tissues. 6. Liver cells break down glycogen into glucose, and adipose tissue cells break down triglycerides into fatty acids and glycerol, providing molecules that can be used by body cells for ATP production. 7. Release of glucose by the liver increases blood glucose level. 8. Processes that are not essential for dealing with the stressful situation are inhibited. For example, muscular movements of the gastrointestinal tract and digestive secretions slow down or even stop.

SIGNAL transmission at a neuroeffector junction: 1 An _______ potential arrives at a ________ of the autonomic POSTganglionic axon. 2 The _______ phase of the action potential opens voltage-gated ______ channels, which are present in the varicosity membrane. Because calcium ions are _____concentrated in extracellular fluid, Ca2+ flows ________ through the opened channels. 3 An increase in the Ca2+ concentration inside the varicosity serves as a signal that triggers __________ of the synaptic vesicles, causing the release of neurotransmitter into the synapse. 4 The neurotransmitter molecules _______ across the synapse and bind to neurotransmitter receptors in the effector cell's _________ membrane. 5 Binding of neurotransmitter to its receptor activates a ___ _________, ultimately leading to a response that either ________ or ________ the effector cell, DEPENDING on the type of receptor and G protein pathway that are activated.

1. action potential; varicosity 2. depolarizing; Ca2+; MORE; INWARD 3. exocytosis 4. Diffuse; plasma 5. G protein; excites or inhibits

Several chemical agents selectively alter certain events at the neuromuscular junction (NMJ). What are the substances?

1. botulinum toxin, 2. α-latrotoxin, 3. curare, 4. organophosphates.

What are three important parasympathetic responses? HINT: "three decreases"

1. decreased heart rate, 2. decreased diameter of the bronchial tubes of the lungs (bronchoconstriction), 3. decreased diameter of the pupils (pupillary constriction)

What are the activities are stimulated by the parasympathetic nervous system? HINT: SLUDD

1. salivation (S), 2. lacrimation (L), 3. urination (U), 4. digestion (D), 5. defecation (D)

An autonomic reflex arc consists of what following components? HINT: FIVE

1. sensory receptor, 2. sensory neuron, 3. integrating center, 4. autonomic motor neurons, 5. a visceral effector.

A few structures receive ONLY sympathetic innervation, which are? In these structures, there is NO opposition from the parasympathetic nervous system. Still, an increase in sympathetic tone has one effect, and a decrease in sympathetic tone produces the opposite effect.

1. sweat glands, 2. arrector pili muscles attached to hair follicles in the skin, 3. the kidneys, 4. the spleen, 5. most blood vessels, and 6. the adrenal medullae of the adrenal glands.

The hypothalamus receives sensory input related to? (HINT: Six) The hypothalamus also receives input relating to emotions from the _______ system.

1. visceral functions, 2. olfaction (smell), 3. gustation (taste), 4. temperature, 5. osmolarity, 6. levels of various substances in blood. 7. limbic system

How does a neuroeffector junction (NEJ) differ from a typical neuron-to-neuron synapse?

A neuroeffector junction (NEJ) differs from a typical neuron-to-neuron synapse in two main ways: (1) The axon terminals exhibit varicosities instead of synaptic end bulbs AND (2) the neurotransmitter receptors are located along the entire surface of the effector cell instead of being confined to a specific receptor region

Somatic nervous system: What effect does the ACh released by the somatic motor neuron have on skeletal muscle?

ACh released by a somatic motor neuron always causes excitation (contraction) of skeletal muscle.

What are the neurotransmitters that can be released by nonadrenergic, noncholinergic neurons?

Adenosine, ATP, nitric oxide, somatostatin, substance P, and vasoactive intestinal polypeptide (VIP).

How is an end plate potential (EPP) similar to an excitatory postsynaptic potential (EPSP)? How does it differ?

An EPP and an EPSP are both depolarizing graded potentials. However, an EPP occurs at a neuromuscular junction, whereas an EPSP occurs at a synapse between neurons. In addition, an EPP has a larger amplitude (size) than an EPSP, so a single EPP typically is large enough to depolarize a muscle fiber to threshold, but a single EPSP normally is too small to depolarize a neuron to threshold.

__________ (_________) reflexes are fast, involuntary responses that occur when action potentials pass through an autonomic reflex arc.

Autonomic (visceral)

Action potentials triggered by the integrating center propagate out of the CNS along autonomic motor neurons to an effector. In an autonomic reflex arc, two ________ __________ ___________ connect the CNS to an effector: The preganglionic neuron conducts action potentials from the CNS to an autonomic ganglion, and the postganglionic neuron conducts action potentials from an autonomic ganglion to the effector. Which of the autonomic reflex arc is this? A. sensory receptor, B. sensory neuron, C. integrating center, D. autonomic motor neurons, E. a visceral effector.

Autonomic motor neurons.

What are some examples of activities in the body that are regulated by autonomic reflexes?

Autonomic reflexes help regulate cardiovascular activities, digestion, defecation, and micturition (urination).

Activation of ANS motor pathway always causes excitation of the effector organ •a. T •b. F

B. FALSE

Thalamus balances opposing effects of ANS pathways. a. T b. F

B. FALSE

At the top of the autonomic nervous system hierarchy, the __________ controls most of the autonomic nervous system functions via the reticular formation. a. thalamus b. hypothalamus c. limbic system d. pituitary gland

B. Hypothalamus

Electronic-monitoring devices display information about a body function such as heart rate or blood pressure, enhances the ability to learn such conscious control. The monitoring devices provide visual or auditory signals about the autonomic responses. By concentrating on positive thoughts, individuals learn to alter autonomic response. This is known as?

Biofeedback

Output from the hypothalamus influences autonomic centers in both the _______ _______ and _______ ______; VIA the _______ ________

Brain stem and Spinal cord; Reticular Formation

In the parasympathetic nervous system, preganglionic neurons have their cell bodies in the _______ _______ and _______ _______ of the spinal cord.

Brain stem; sacral regions

Through the process of __________, seemingly involuntary activities can be voluntarily controlled. a. hypnosis b. biology c. biofeedback d. involuntary control

C. Biofeedback

A synonym for the autonomic nervous system reflects its major function. The synonym is ____________. a. the peripheral nervous system b. the central nervous system c. the involuntary nervous system d. the somatic nervous system

C. The involuntary nervous system

____________ cells are modified sympathetic POSTganglionic neurons that release the hormones epinephrine and norepinephrine (NE) into the blood.

Chromaffin

Botulinum toxin, produced by the bacterium ________ __________, blocks ___________ of synaptic vesicles at the NMJ. As a result, acetylcholine (ACh) is _____ released, and muscle contraction _____ ______ occur. The bacteria proliferate in improperly canned foods, and their toxin is one of the most lethal chemicals known. A tiny amount can cause death by _________ skeletal muscles. Breathing stops because respiratory muscles (which are skeletal muscles) are ___________. Despite these lethal effects, botulinum toxin can be used in small, diluted amounts as a _________. Injections of Botox into the affected muscles can help patients who have ___________, _________ ________ or ________ of the vocal cords that interfere with speech. Botox is also used as a _____________ treatment to relax muscles that cause facial ___________ and to alleviate chronic ________ pain due to muscle spasms.

Clostridium botulinum; exocytosis Not; does not paralyzing; paralyzed. medicine (Botox®) strabismus (crossed eyes), uncontrollable blinking, or spasms cosmetic; wrinkles; back

The _______ of an autonomic reflex arc is smooth muscle, cardiac muscle, or a gland. Which of the autonomi reflex arc is this? A. sensory receptor, B. sensory neuron, C. integrating center, D. autonomic motor neurons, E. a visceral effector.

Effector.

Parasympathetic preganglionic axons exit the CNS through ____ cranial nerves (___, ___, ___, and ___) and several ______ spinal nerves (S2-S4). The axons then extend to parasympathetic post ganglionic neurons in _________ _________, which are located close to or within the wall of the visceral effector. From the terminal ganglia, parasympathetic postganglionic axons extend to cells in the ________ ________. Because terminal ganglia are located either close to or in the wall of the visceral effector, parasympathetic preganglionic axons are ______, and parasympathetic postganglionic axons are ________.

Four; (III, VII, IX, and X); sacral Terminal ganglia; visceral organ; Long; Short

The α1 receptors activate ___ proteins that trigger _____/_____ the second messenger pathway, which increases intracellular Ca2+ levels. The α2 receptors activate ___ proteins, which inhibit _______ _______ and decrease _________ levels. β1, β2, and β3 receptors ALL activate Gs proteins, which __________ adenylyl cyclase and ________ cAMP levels.

Gq; IP3/DAG Gi; adenylyl cyclase; cAMP activate; increase

What determines whether the effector cell is excited or inhibited by the binding of neurotransmitter to its receptor?

In response to neurotransmitter binding to its receptor, the effector cell is either excited or inhibited, depending on the type of receptor and G protein pathway that are activated.

The _________ _________ is a region of gray matter within the CNS that processes the incoming sensory input. The _______ _______ may involve just one synapse between the sensory neuron and a motor neuron, or it may involve one or more interneurons that relay signals from the sensory neuron to the motor neuron. The _______ ________ for most autonomic reflexes are located in the hypothalamus and brain stem. However, some autonomic reflexes have _______ _____ in the spinal cord. Which of the autonomic reflex arc is this? A. sensory receptor, B. sensory neuron, C. integrating center, D. autonomic motor neurons, E. a visceral effector.

Integrating center.

Filling in the type of Muscarinic ACh receptor: _____, _____, _______ receptors activate a Gq protein and phospholipase C to trigger the inositol trisphosphate (IP3)/diacylglycerol (DAG) second messenger pathway that increases intracellular Ca2+ levels, resulting in excitation of the effector cell. ____ and ____ receptors activate a Gi protein, which inhibits adenylyl cyclase and decreases cAMP levels, resulting in the opening of K+ channels and inhibition of the effector cell. In the heart, which has ____ receptors, the Gi protein can directly open K+ channels without altering adenylyl cyclase activity or the cAMP level.

M1, M3, and M5; M2 and M4 M2

Which ANS neurons are adrenergic?

Most (BUT NOT ALL) sympathetic POSTganglionic neurons are adrenergic.

Somatic Nervous System: Which part of the muscle plasma membrane contains acetylcholine receptors?

Motor end plate.

The autonomic and somatic nervous systems contribute to homeostasis by conveying ___________ output from the central nervous system to __________ ( __________ and ___________ ) for appropriate responses to integrated sensory information.

Motor; effectors (muscles and glands)

The nicotinic ACh receptor subtype found in SKELETAL muscle at the neuromuscular junction is _____. The subtype present in dendrites and cell bodies of the parasympathetic and sympathetic postganglionic neurons AND in chromaffin cells is ____.

N1; N2

What are two types of cholinergic receptors?

Nicotinic acetylcholine receptors and Muscarinic acetylcholine receptors

Does activation of autonomic motor pathways always result in excitation of their effectors? Explain your answer.

No. Activation of autonomic motor pathways results in excitation of some effectors and inhibition of others.

Some autonomic neurons release neither norepinephrine nor acetylcholine, these neurons are called?

Nonadrenergic, noncholinergic neurons

___________ responses support body functions that conserve and restore body energy during times of rest and recovery. When the body is relaxed, parasympathetic input to the ________ glands and the ________ muscle of the gastrointestinal tract ______________ over sympathetic input. This allows energy-supplying food to be ________ and ____________. At the same time, parasympathetic responses __________ body functions that support physical activity.

Parasympathetic; digestive; smooth; predominate digested; absorbed reduce

Despite the presence of sensory neurons and interneurons, the Enteric Nervous System is considered to be part of the efferent (motor) division of the _________ Nervous System because of its association with the Autonomic Nervous System.

Peripheral Nervous System

If the receptor potential in the sensory receptor reaches threshold, it will generate one or more action potentials in the axon of the _________ _________. The action potentials are conveyed along the axon into the CNS. Which of the autonomic reflex arc is this? A. sensory receptor, B. sensory neuron, C. integrating center, D. autonomic motor neurons, E. a visceral effector.

Sensory neuron.

Somatic Nervous System: True or False. A neuromuscular junction thus includes all of the synaptic end bulbs on one side of the synaptic cleft, the synaptic cleft itself, plus the motor end plate of the muscle fiber on the other side.

TRUE

Somatic Nervous System: When action potentials in the motor neuron cease (come to an end), ACh is no longer released, and AChE rapidly breaks down the ACh already present in the synaptic cleft. This ends the production of action potentials in the skeletal muscle fiber.

TRUE

Somatic nervous system: True or False When a somatic motor neuron stimulates a skeletal muscle, it contracts. If somatic motor neurons cease to stimulate a skeletal muscle, the result is a paralyzed, limp muscle that has no muscle tone.

TRUE

Somatic nervous system: True or False. If you want to perform a particular movement (kick a ball, turn a screwdriver, smile for a picture, etc.), neural pathways from the motor cortex activate somatic motor neurons that cause the appropriate skeletal muscles to contract.

TRUE

Somatic nervous system: True or False. In a somatic motor pathway, a single somatic motor neuron extends to a skeletal muscle.

TRUE

True or False Although most people are unable to consciously alter or suppress autonomic responses to any great degree, practitioners of yoga or other techniques of meditation may learn how to regulate at least some of their autonomic activities through long practice

TRUE

True or False. Compared to ACh, norepinephrine lingers in the synaptic cleft for a longer time. Thus, effects triggered by adrenergic neurons typically are longer lasting than those triggered by cholinergic neurons.

TRUE

True or False. Nicotine acetylocholine RECEPTORS are so-named because the drug nicotine mimics the action of ACh by binding to these receptors

TRUE

True or False. The hypothalamus is connected to both parasympathetic and sympathetic branches of the ANS by axons of neurons with dendrites and cell bodies in various hypothalamic nuclei

TRUE

True or False. The somatic nervous system is NOT always under voluntary control, however. The somatic motor neurons that innervate skeletal muscles involved in posture, balance, breathing, and somatic reflexes (such as the flexor reflex) are involuntarily controlled by integrating centers in the brain stem and spinal cord.

TRUE

True or False. You probably cannot voluntarily slow down your heart rate; instead, your heart rate is subconsciously regulated.

TRUE

True or False: Activation of muscarinic ACh receptors either excites or inhibits the effector cell, depending on which subtype of muscarinic ACh receptor is activated.

TRUE

True or False: Cells of most effectors contain either alpha or beta receptors; some visceral effector cells contain both.

TRUE

True or False: Nicotine does not activate muscarinic receptors, and muscarine does not activate nicotinic receptors, BUT ACh does activate both types of cholinergic receptors.

TRUE

True or False: Once Norepinephrine is released from an adrenergic neuron, it diffuses across the synaptic cleft and binds to specific adrenergic receptors on the postsynaptic membrane, causing either excitation or inhibition of the effector cell.

TRUE

True or False: Release of neurotransmitter at the Neuroeffector juntion occurs in the same way as at a typical neuron-to-neuron synapse.

TRUE

True or False: The activity of acetylcholine at a synapse is terminated by enzymatic degradation via acetylcholinesterase (AChE). Because AChE quickly breaks down acetylcholine, effects triggered by cholinergic neurons are brief.

TRUE

True or False: Visualizing body changes that occur during "E situations" such as exercise, emergency, excitement, and embarrassment will help you remember most of the sympathetic responses

TRUE

True or False: When an action potential occurs in the autonomic postganglionic neuron, varicosities along the length of the axon release neurotransmitters, which in turn diffuse to receptors throughout the effector. As a result, the autonomic postganglionic neuron affects a large area of the effector tissue

TRUE

True or False: Once ACh is released from a cholinergic neuron, it diffuses across the synaptic cleft and binds with specific cholinergic receptors, integral membrane proteins in the postsynaptic plasma membrane.

TRUE

True or False: Removal of the neurotransmitter from the NEJ occurs by the same mechanisms as in a neuron-to-neuron synapse: (1) _________ away from the synapse, (2) __________ by enzymes in extracellular fluid or plasma membrane of the effector cell, or (3) uptake into a nearby cell via _______ transport.

TRUE; 1. DIFFUSION; 2. DEGRADATION; 3. ACTIVE

True or False. Skeletal muscle, tissues innervated by the Autonomic Nervous System often function to some extent even if their nerve supply is damaged or cut. The heart continues to beat when it is removed for transplantation into another person, smooth muscle in the lining of the gastrointestinal tract contracts rhythmically on its own, and glands produce some secretions in the absence of Autonomic Nervous System control.

TRUE; TRUE

True or False. The ANS was so-named because it was thought to function autonomously or in a self-governing manner (autonomic = autonomous), without control by the CNS. However, centers in the brain and spinal cord do regulate autonomic activities.

TRUE; TRUE

True or False: Most body organs receive innervation from both parasympathetic and sympathetic branches of the ANS, which typically work in opposition to one another. The balance between parasympathetic and sympathetic activity, called ________ ______, is regulated by the __________.

TRUE; autonomic tone; hypothalamus

True or False: Sympathetic preganglionic axons exit the CNS through thoracic and lumbar spinal nerves. After leaving the CNS, MOST sympathetic preganglionic axons extend to sympathetic POSTganglionic neurons in the ____________ ________, a chain of ganglia located on either side of the spinal cord. OTHER sympathetic preganglionic axons extend to sympathetic POSTganglionic neurons in ___________ ________, individual ganglia that are not associated with the sympathetic trunk

TRUE; sympathetic trunk; collateral ganglia

Which part of the brain is considered to be the major control and integrating center of the ANS?

The hypothalamus is the major control and integration center of the ANS

True or False Autonomic motor pathways (both parasympathetic and sympathetic) consist of two autonomic motor neurons in series and a visceral effector (smooth muscle, cardiac muscle, or a gland)

True

True or False. Adrenergic receptors are metabotropic receptors that trigger second messenger pathways by coupling to G proteins

True

True or False. Biofeedback has been used to decrease heart rate and blood pressure in order to decrease the severity of migraine headaches.

True

True or False. Nonadrenergic, noncholinergic neurons are classified as part of the parasympathetic nervous system or sympathetic nervous system based on where the preganglionic neurons exit the CNS.

True

True or False. Normally, we are not aware of muscular contractions of our digestive organs, our heartbeat, changes in the diameter of our blood vessels, and pupil dilation and constriction because the integrating centers for these autonomic responses are in the spinal cord or lower regions of the brain

True

True or False. The parasympathetic and sympathetic can affect body organs differently because their postganglionic neurons release different neurotransmitters and because the effector organs possess different cholinergic and adrenergic receptors.

True

True or False. Typically, the hypothalamus turns down parasympathetic tone at the same time it turns up sympathetic tone, and vice versa

True

True or False: Muscarine acetylcholine receptors are so-named because a mushroom poison called muscarine mimics the actions of ACh by binding to them.

True

True or False. High sympathetic tone favors body functions that can support vigorous physical activity and rapid production of ATP. At the same time, the sympathetic nervous system reduces body functions that favor the storage of energy.

True; True

How do chromaffin cells differ from other sympathetic postganglionic neurons?

Unlike most sympathetic postganglionic neurons, chromaffin cells lack dendrites and axons and they release hormones into the blood.

Which of the following does not describe the autonomic nervous system? a) the effectors are primarily skeletal muscles b) the sympathetic division generally stimulates an organ c) preganglionic axons release acetylcholine d) it is under involuntary control e) the parasympathetic division decreases heart rate

a) the effectors are primarily skeletal muscles

Cholinergic neurons release the neurotransmitter _________________.

acetylcholine (ACh).

Organophosphates are chemicals that inhibit __________________ Inhibition of AChE at the NMJ initially causes ____________ contractions of skeletal muscles and then causes muscle _________ as muscle fibers become refractory to further stimulation. Organophosphates include the nerve ______ _______, which is used in chemical warfare, and __________, which is an ingredient used in certain insecticides.

acetylcholinesterase (AChE); uncontrolled; paralysis gas sarin; malathion

Most sympathetic postganglionic neurons are _______

adrenergic

What are the two main types of adrenergic receptors?

alpha (α) receptors and beta (β) receptors.

The _________ and __________ parts of the hypothalamus control the parasympathetic nervous system. Stimulation of these areas results in a ________ in heart rate, ________ of blood pressure, __________ of the pupils, and ___________ secretion and ________ of the gastrointestinal tract.

anterior and medial decrease; lowering; constriction, increased; motility

Adjustment of the rate and force of the heartbeat, dilation or constriction of the bronchial tubes of the lungs, and secretion of digestive glands are examples of ___________ responses

autonomic

The __________ nervous system conveys output from the CNS to smooth muscle, cardiac muscle, and glands. Because its motor responses are not normally under conscious control, the action is involuntary

autonomic

The parasympathetic nervous system originates in the _____ ______ and _______ region of the spinal cord. The sympathetic nervous system originates in the _________ and ________ regions of the spinal cord.

brain stem and sacral region; Thoracic and Lumbar

Somatic nervous system: The CELL bodies of somatic motor neurons are located in either the _____ ________ or _____ ______ _____ of the spinal cord. From the brain stem, axons of somatic motor neurons extend through cranial nerves to innervate skeletal muscles of the _______ and _______. From the spinal cord, axons of somatic motor neurons extend through spinal nerves to innervate skeletal muscles of the ______ and ______.

brain stem or ventral gray horn; face and head; limbs and trunk

β3 receptors are present mainly on the cells of _______ ______ tissue, where their activation causes ____________.

brown adipose; thermogenesis (heat production)

1)Which of the following comparisons of the autonomic nervous system (ANS) and the somatic nervous system (SNS) is NOT true? a) the SNS carries information from the special senses b) the ANS has sensory receptors called interoceptors c) the SNS contains motor neurons which are only excitatory d) angina pectoris is an example of input from the ANS

c) the SNS contains motor neurons which are only excitatory

Autonomic reflexes play a key role in homeostasis by regulating?

cardiovascular activities, digestion, defecation, and micturition (urination)

The activity of norepinephrine at a synapse is terminated either when the NE is taken up by the axon that released it or when the NE is enzymatically inactivated by?

catechol-O-methyltransferase (COMT) or monoamine oxidase (MAO)

Somatic nervous system: Voluntary control of movement involves motor areas of the that _______ _________ activate somatic motor neurons whenever you have a desire to move.

cerebral cortex

Based on the neurotransmitters they produce and release, most autonomic neurons are classified as either ___________ or ____________. The receptors for the neurotransmitters are ___________ membrane proteins located in the plasma membrane of the postsynaptic neuron or effector cell

cholinergic or adrenergic; integral

SOME sympathetic PREganglionic axons extend to SPECIALIZED cells called ________ cells in the ________ _______ without synapsing in either the sympathetic trunk or collateral ganglia.

chromaffin; adrenal medulla (inner portion of the adrenal gland)

Integrating center: The reflex is a __________ reflex if integration occurs in the gray matter of the brain. The reflex is a __________ reflex if integration occurs in the gray matter of the spinal cord.

cranial; spinal

The parasympathetic nervous system is also known as the _______________ division of the Autonomic Nervous System.

craniosacral

Nicotinic acetylcholine RECEPTORS are present: 1) in the plasma membranes of the __________ and _____ _______ of both parasympathetic and sympathetic ____________ neurons, 2) in the plasma membranes of __________ cells of the adrenal medulla, 3) in skeletal muscle at the ____________ junction.

dendrites and cell bodies; POSTganglionic; chromaffin; neuromuscular

Nicotinic ACh receptors: Opening the cation channel allows passage of cations (mainly Na+ and K+) through the membrane. Because Na+ is farther away from equilibrium than K+, Na+ inflow is greater than K+ outflow, resulting in ____________. Activation of nicotinic ACh receptors therefore _______ the postsynaptic cell.

depolarization; Excites

During physical or emotional stress, the sympathetic nervous system _____________ the parasympathetic nervous system

dominates

Most organs receive nerves from both, Parasympathetic and Sympathetic Nervous System, of these branches, an arrangement known as _________ ___________. In general, one branch stimulates the organ to ________ its activity (excitation), and the other branch ____________ the organ's activity (inhibition).

dual innervation; increase; decreases

Muscarinic acetylcholine receptors are present in the plasma membranes of the ______________ innervated by ______________ postganglionic axons.

effectors (smooth muscle, cardiac muscle, and glands); parasympathetic

Somatic Nervous System: Binding of acetylcholine (ACh) to nicotinic ACh receptors on the motor end plate causes the formation of an ______ _______ potential, which in turn leads to the initiation of a muscle action potential in adjacent regions of plasma membrane.

end plate potential (EPP)

Somatic Nervous System: The net influx of Na+ ions into the muscle fiber through the open nicotinic ACh receptors causes the motor end plate to depolarize. This change in membrane potential is called an?

end plate potential (EPP)

The Autonomic Nervous System is also comprised of a third branch known as the __________ nervous system (_______).

enteric nervous system (ENS)

Binding of neurotransmitter to receptor molecules in the effector causes a response that leads to ________ or _________ of the effector cell.

excitation or inhibition

There are some exceptions, activation of α1 and β1 receptors generally produces ____________, and activation of α2 and β2 receptors causes __________ of effector tissues.

excitation; inhibition

In addition to physical exertion, various emotions—such as ______, ____________, or ___________—stimulate the sympathetic nervous system

fear, embarrassment, or rage

Activation of the sympathetic nervous system and release of hormones by the adrenal medulla set in motion a series of physiological responses collectively called the _____-or-______ response

fight‐or‐flight

A _______ is a cluster of neuronal cell bodies in the Peripheral Nervous System

ganglion

The Enteric Nervous System consists of millions of neurons in plexuses that extend most of the length of the _______________ tract. It's operation is __________. True or False Although the neurons of the Enteric Nervous System can function autonomously, they can also be regulated by the other branches of the ___________ Nervous System.

gastrointestinal tract (GI); involuntary True; Autonomic Nervous System

Somatic Nervous System: An EPP is a type of ________ potential that is similar to an excitatory postsynaptic potential (EPSP), which forms at synapses between neurons

graded

Adrenergic receptors: The α receptors have a _______ affinity for norepinephrine than epinephrine. β1 receptors have nearly ______ affinity for norepinephrine and epinephrine; β2 receptors have a _______ affinity for epinephrine than norepinephrine; and β3 receptors have a ______ affinity for norepinephrine than epinephrine.

higher; equal; higher; higher

The ______________ is the major control and integrating center of the ANS.

hypothalamus

Autonomic motor neurons regulate visceral activities by either ________ (________) or __________ (__________) ongoing activities in their effectors.

increasing (exciting) or decreasing (inhibiting)

The venom of the black widow spider contains α-latrotoxin, which __________ massive exocytosis of synaptic vesicles at the NMJ. This causes the _________ of excessive amounts of ACh, which leads to overstimulation of skeletal muscles. Prolonged stimulation of respiratory muscles can lead to _________ _______ and ______.

induces; release; respiratory failure and death

The adrenal medulla develops from the same embryonic tissue as the sympathetic ganglia. Therefore, chromaffin cells are ________ __________ ______ganglionic neurons that LACK dendrites and axons. Rather than extending to another organ, however, these cells release __________ into the blood. Upon stimulation by sympathetic preganglionic neurons, the chromaffin cells of the adrenal medulla release a mixture of __________ hormones: about 80% __________, 20% __________, and a trace amount of __________. True or False: These hormones circulate through the body and intensify responses elicited (drawn out) by the sympathetic nervous system.

modified sympathetic postganglionic; hormones; catecholamine; epinephrine; norepinephrine; dopamine TRUE

The plant derivative curare, a poison used by South American Indians on arrows and blowgun darts, causes __________ ________ by binding to and ____________ nicotinic ACh receptors on the motor end plate. In the presence of curare, the cation channel of the nicotinic ACh receptor does ______ _______. Curare-like drugs are often used during surgery to _______ skeletal muscles.

muscle paralysis; blocking not open relax

The synapse between an Autonomic POSTganglionic neuron and a visceral effector is called the ____________ junction.

neuroeffector junction (NEJ)

In the ANS: norepinephrine can be released as a ________________ (by sympathetic postganglionic neurons) or as a ________ (by chromaffin cells of the adrenal medulla); epinephrine is released as a ________.

neurotransmitter; hormone hormone

The _____________ nervous system enhances rest-and-digest activities, which conserve and restore body energy during times of rest and recovery

parasympathetic

Some autonomic responses are the basis for ___________ ("____ ______") tests

polygraph; lie detector

The ________ and __________ parts of the hypothalamus control the sympathetic nervous system. Stimulation of these areas produces an __________ in heart rate and force of contraction, a ________ in blood pressure due to ___________ of blood vessels, an __________ in body temperature, __________ of the pupils, and ___________ of the gastrointestinal tract.

posterior and lateral increase; rise; constriction; increase; dilation; inhibition

Autonomic motor pathways: (1) a ___________ neuron, which extends from the CNS to an autonomic ganglion (2) a ____________ neuron, which extends from the autonomic ganglion to the effector (smooth muscle, cardiac muscle or a gland).

preganglionic neuron; postganglionic neuron

In the ANS, cholinergic neurons include: (1) ALL parasympathetic and sympathetic ____________ neurons, (2) MOST parasympathetic ____________ neurons, and (3) sympathetic postganglionic neurons that innervate most _________ gland

preganglionic; postganglionic; sweat

Autonomic pathway motor: The first neuron, called the _________ neuron, has its cell body in the brain or spinal cord. Its axon exits the Central Nervous System via a cranial or spinal nerve and then extends to an ________ ganglion, where it synapses with the second neuron. The second neuron, called the ______________ neuron, lies entirely in the Peripheral Nervous System. Its cell body is located in the autonomic ganglion, and its axon extends from the ganglion to the ________ effector

preganglionic; autonomic postganglionic; visceral

The ________ ________ is the distal end of a sensory neuron; it responds to a stimulus by producing a receptor potential. The __________ _______ of an autonomic reflex are usually interoceptors, which respond to internal stimuli, such as the degree of stretch of an organ wall or the chemical composition of a body fluid. Which of the autonomic reflex arc is this? A. sensory receptor, B. sensory neuron, C. integrating center, D. autonomic motor neurons, E. a visceral effector.

sensory receptor

Somatic nervous system: Somatic motor pathways consist of a _______ somatic motor neuron that originates in the _______ and extends its axon to one or more fibers (cells) of a skeletal muscle.

single; CNS

The somatic nervous system innervates the _______ muscles of the body

skeletal

The autonomic nervous system (ANS) innervates _______ _______, ________ _________, and __________. These tissues are often referred to as ___________ ____________ because they are usually associated with the viscera (internal organs) of the body.

smooth muscle, cardiac muscle, and glands. visceral effectors

The _________ nervous system conveys output from the CNS to skeletal muscles. Because its motor responses can be consciously controlled, the action of the somatic nervous system is voluntary.

somatic

The _____________ nervous system promotes the fight-or-flight response, which prepares the body for emergency situations

sympathetic

Most SWEAT glands receive their INNERVATION from cholinergic ____________ POSTganglionic neurons and possess ______________ ACh receptors

sympathetic; muscarinic

Somatic nervous system: At the NMJ, a terminal branch of the somatic motor neuron's axon divides into a cluster of _______ ______ ______, which contain synaptic vesicles. Inside each synaptic vesicle are thousands of molecules of ___________, the neurotransmitter released at the NMJ. ACh has an ________ effect on the NMJ, ultimately causing the skeletal muscle fiber to contract. The region of the muscle fiber plasma membrane opposite the synaptic end bulbs is called the ______ ______ ____. Within the motor end plate are 30 to 40 million ____________ __________ (of the nicotinic type) that bind specifically to ACh. The ACh receptors are abundant in ________ ________, deep grooves in the motor end plate that provide a large surface area for ACh. Although the synaptic end bulbs and motor end plate are close to each other, they do not actually touch; instead, they are separated by a small space called the _______ _______.

synaptic end bulbs acetylcholine (ACh) excitatory motor end plate acetylcholine receptors junctional folds; synaptic cleft;

What are the autonomic control centers in the brain stem? HINT: Six

the cardiovascular, respiratory, deglutition (swallowing), salivation, vomiting, and pupillary reflex centers

What are the autonomic control centers in the spinal cord? HINT: Four

the erection, ejaculation, defecation, and micturition (urination) centers

Somatic nervous system: The synapse formed between a somatic motor neuron and a skeletal muscle fiber is called?

the neuromuscular junction (NMJ)

What are the two main branches that the Autonomic Nervous System consist of?

the parasympathetic nervous system and the sympathetic nervous system.

In the sympathetic nervous system, preganglionic neurons have their cell bodies in the ________ and _______ ________ regions of the spinal cord

thoracic and upper lumbar

The sympathetic nervous system is also called the __________ division of the ANS

thoracolumbar

Autonomic postganglionic neurons release neurotransmitters from ________, which are swollen regions found at the ends of axon terminals.

varicosities

The organization of the Neuroeffector junction differs from a typical neuron-to-neuron synapse in two major ways: 1. The axon terminals of the postganglionic neuron lack synaptic end bulbs; instead, they exhibit SWOLLEN regions called ____________, which contain synaptic vesicles with neurotransmitter. 2. In the effector, the receptors for the neurotransmitters are not confined to a specific receptor region; rather, they are located along the _______ surface of the cell.

varicosities; Entire

From the sympathetic trunk or collateral ganglia, sympathetic postganglionic axons extend to the ___________ __________. Because sympathetic trunk ganglia are located near the spinal cord, MOST sympathetic PREganglionic axons are ______ and MOST sympathetic POSTganglionic axons are _______.

visceral effector; short; long

In the ANS, alpha (α) receptors and beta (β) receptors are found on ________ _________ innervated by most sympathetic POSTganglionic axons

visceral effectors

The somatic nervous system usually operates under __________ control.

voluntary (conscious)

The Autonomic Nervous System usually operates _______ conscious control. A. With B. Without

without