physio chapter 11
sympathetic preganglionic neurons exit the spinal nerve via the _______ before they enter the ________
white ramus: ganglion of the sympathetic trunk
Which of the following is NOT a visceral reflex? A) pupillary light reflex B) withdrawal reflex C) vomitingD) urination E) swallowing
withdrawal reflex
what type of receptor agonists are used to treat people suffering from asthma or nasal congestion
beta 2
dual innervation of organs by the autonomic nervous system refers to the observation that
both sympathetic and parasympathetic neurons innervate most organs
when the body is stressed what is the relative contribution of the sympathetic and parasympathetic nervous systems to the regulation of homeostasis
both systems are active bu the sympathetic predominates
At rest, what is the relative contribution of the sympathetic and parasympathetic nervous systems to the regulation of homeostasis?
both systems are active but the parasympathetic predominates
where are most of the autonomic nervous system control centers located
brainstem
Where in the central nervous system do the preganglionic neurons of the parasympathetic nervous system originate?
brainstem and sacral region of the spinal cord
in what class of neuron and within what organelle is the enzyme monoamine oxidase located
mitochondria of sympathetic postganglionic neurons
mismatches between vestibular, visual, and proprioceptive sensory inputs activate the autonomic nervous system leading to symptoms that are characteristic of ____________
motion sickness
where on skeletal muscle is the highest density of nicotinic receptors
motor end plate
what cholinergic receptors are coupled to G proteins
muscarinic
which class of autonomic nervous system receptors is ionotropic
nicotinic cholinergic
binding of acetylcholine to________receptors cause a ____________ by opening channels that permit both sodium and potassium to permeate the membrane
nicotinic: depolarization
Which of the following contributes to the ability of the sympathetic nervous system to produce widespread responses within the body? A) multiple preganglionic neurons innervate each ganglion, sending out individual postganglionic neurons B) one postganglionic neuron branches into many collaterals that affect multiple organs C) one preganglionic neuron sends collaterals to multiple ganglia, affecting multiple postganglionic neurons D) one preganglionic neuron can activate only one postganglionic neuron E) several preganglionic neurons activate a single postganglionic neuron
one preganglionic neuron sends collaterals to multiple ganglia affecting multiple postganglionic neurons
Which of the following descriptions is TRUE for the parasympathetic nervous system, but NOT the sympathetic nervous system? A) Some preganglionic neurons originate in the spinal cord. B) Some ganglia are connected together in a chain. C) Preganglionic fibers release acetylcholine. D) Postganglionic fibers release acetylcholine. E) Receptors on effector organs are nicotinic cholinergic.
postganglionic fibers release acetylcholine
the somatic nervous system regulates the activity of __________
skeletal muscle
the autonomic nervous system innervates all the following effector organs and tissues except A) skeletal muscles B) cardiac muscles C) endocrine glands D) adipose tissues E) exocrine glands
skeletal muscles
Which of the following neurons of the efferent branch of the peripheral nervous system does NOT release acetylcholine? A) sympathetic preganglionic neuronB) parasympathetic preganglionic neuron C) sympathetic postganglionic neuronD) parasympathetic postganglionic neuron E) motor neuron
sympathetic postganglionic neuron
the balance between sympathetic and parasympathetic activity is modified primarily by __________
the activity of the body
The steps of synaptic transmission at the motor end plate are listed below, out of order. Choose the correct order. 1.Acetylcholine binds to postsynaptic receptors. 2.Acetylcholine is released by exocytosis. 3.A graded depolarization is produced. 4.An action potential is produced on the muscle cell membrane. 5.Channels for both sodium and potassium are opened. 6.Voltage-dependent calcium channels on the plasma membrane open. 7.An action potential arrives at the axon terminal.
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Which of the following are indicative of the relative release of catecholamines from the adrenal medulla? A) 80% epinephrine : 20% dopamineB) 80% norepinephrine : 20% dopamine C) 80% norepinephrine : 20% epinephrine D) 80% epinephrine : 20% norepinephrine E) 100% acetylcholine
80% epinephrine: 20% norepinephrine
the gray ramus is comprised of what fiber type
C
Which of the following cranial nerves does NOT include parasympathetic nerves? A) III - oculomotor nerve B) V - trigeminal nerveC) VII - facial nerveD) IX - glossopharyngeal nerve E) X - vagus nerve
V-trigeminal nerve
compared to norepinephrine, epinephrine has a greater affinity for what type of receptor
beta 2
parasympathetic neurons from which cranial nerve innervate most of the viscera in the thoracic and abdominal cavities
X (10)
with respect to their innervation, individual skeletal muscle fibers (cells) are innervated by
a single motor neuron
parasympathetic preganglionic neurons release the neurotransmitter _______; sympathetic preganglionic neurons release the neurotransmitter___________
acetylcholine: acetylcholine
parasympathetic postganglionic neurons release the neurotransmitter_________: sympathetic postganglionic neurons release the neurotransmitter _________
acetylcholine: norepinphrine
Which of the following is located between the invaginations of the motor end plate of a neuromuscular junction? A) β2 receptors B) β3 receptors C) Acetylcholinesterase D) Muscarinic receptors E) Nicotinic receptors
acetylcholinesterase
what enzyme degrades the neurotransmitter released from varicosities of parasympathetic postganglionic neurons
aceytlcholinesterase
Which of the following endocrine glands is innervated by sympathetic preganglionic neurons? A) adrenal cortex B) adrenal medulla C) thyroid glandD) anterior pituitary E) pancreas
adrenal medulla
binding of norepinephrine to what type of receptor will trigger the activation of phospholipase C
alpha 1
activation of which class of adrenergic receptor will result in calcium release from intracellular stores
alpha 1 only
actions at which class of adrenergic receptor generally have excitatory effects
alpha 1, alpha2, beta 1, and beta 3
activation of which class of adrenergic receptor decreases the cytosolic levels of cAMP
alpha 2 only
what class of adrenergic receptors activates the enzyme adenylate cyclase
beta 1, beta 2, and beta 3
Which of the regions of the brain listed below is NOT involved in the control of the autonomic nervous system? A) hypothalamus B) pons C) medulla oblongata D) cerebellum E) limbic system
cerebellum
what cells of the adrenal medulla release epinephrin
chromaffin cells
Which of the following descriptions of collateral ganglia is true? A) Collateral ganglia are part of the somatic nervous system, located where the motor neuron leaves the ventral horn. B) Collateral ganglia are part of the somatosensory system, located off of the afferent neuron just prior to entering the spinal cord dorsal horn. C) Collateral ganglia are located within the effector organs and are the sites of communication between parasympathetic preganglionic neurons and postganglionic neurons. D) Collateral ganglia are located within a chain just outside the spinal cord and are the sites of communication between sympathetic preganglionic neurons and postganglionic neurons. E) Collateral ganglia are in the sympathetic nervous system but distinct from the sympathetic chain, and they function as a site of communication between sympathetic preganglionic neurons and postganglionic neurons.
collateral ganglia are in the sympathetic nervous system but distinct from the sympathetic chain and they function as a site of communication between sympathetic preganglionic neurons and postganglionic neurons
parasympathetic preganglionic neurons travel in what nerves
cranial and pelvic nerves
the opening of a cation channel that allows both Na+ and K= to move through will cause the membrane to_______ because of the ___________
depolarize; greater Na+ electrochemical gradient as compared with K+
what is the neurotransmitter released from motor neurons
dopamine
Which of the following does NOT have nicotinic cholinergic receptors? A) skeletal muscle cells B) parasympathetic postganglionic neuron cell bodiesC) sympathetic postganglionic neuron cell bodiesD) effector organs for the parasympathetic nervous system E) chromaffin cells
effector organs for the parasympathetic nervous sytem
what is the graded change in membrane potential that occurs at the motor end plate of skeletal muscle called
end plate potential
Which of the following physiological responses are associated with an elevation in parasympathetic nervous system activity? A) shifting blood flow away from the gastrointestinal tract B) enhanced absorption of nutrients C) increased heart rateD) increased contractile force of the heart E) enhanced mobilization of energy stores
enhanced absorption of nutrients
true or false a motor unit consists of a skeletal muscle fiber (cell) and all of the motor neurons that innervate that skeletal muscle fiber
false
true or false all autonomic nerves contain only efferent fibers
false
true or false atropine, first derived from the atropa belladonna plant is a nicotinic receptor agonist
false
true or false binding of a ligand to the alpha 1 adrenergic receptor activates Gi, thereby the synthesis of cAMP
false
true or false physiological stressors will cause parasympathetic nervous system activity to increase
false
true or false the primary hormone released from the adrenal medulla is norepinephrine
false
true or false the somatic nervous system provides both excitatory and inhibitory signals to skeletal muscle
false
what area of the brain initiates the fight or flight response by producing widespread activation of the sympathetic nervous system
hypothalamus
hich of the following physiological responses are associated with elevated sympathetic nervous system activity? A) enhanced digestionB) enhanced absorption of nutrients C) decreased heart rateD) increased contractile force of the heart E) inhibition of cardiovascular function
increased contractile force of the heart
within the autonomic ganglia, what are the cells that modulate the flow of information to the target organ called
intrinsic neurons
how does latroxin the venom of the black widow spider cause muscle spasms and rigidity
it simulates acetylcholine release from motor neurons
Which of the following structures of an autonomic neuron is NOT located within the ganglion? A) the cell body of preganglionic neuronsB) the terminal axon of preganglionic neurons C) the intrinsic neuronsD) the cell body of postganglionic neurons E) the dendrites of postganglionic neurons
the cell body of preganglionic neurons
Which of the following statements is TRUE of communication across the neuromuscular junction? A) Acetylcholine released from a motor neuron binds to muscarinic cholinergic receptors. B) The end-plate potential is always of sufficient magnitude to depolarize the muscle cell to threshold to initiate an action potential. C) Acetylcholinesterase located in the cytosol of the motor neuron degrades acetylcholine to acetate and choline. D) Acetylcholinesterase located in mitochondria of the motor neuron degrades acetylcholine to acetate and choline. E) Synaptic communication to the muscle cell can be excitatory or inhibitory. Answer: B
the end plate potential is always of sufficient magnitude to depolarize the muscle cell to threshold to initiate and action potential
Where do the preganglionic neurons of the sympathetic nervous system emerge from the spinal cord?
thoracic and lumbar regions
true or false the preganglionic neurons of the sympathetic nervous system originate in the spinal cord from a region of gray matter called the intermediolateral cell column
treu
true or false according to the theory of dual innervation the two branches of the autonomic nervous system innervate the same effector organ but tend to have opposite effects on those organs
true
true or false acetylcholine binding to nicotinic cholinergic receptors always excites the postsynaptic cell
true
true or false alpha adrenergic receptors have a greater affinity for norepinphrine than for epinephrine
true
true or false some visceral reflexes are spinal reflexes
true
true or false sympathetic preganglionic neurons traveling to collateral ganglia travel through ganglia of the sympathetic trunk without making synaptic communication
true
true or false the autonomic nervous system consists of efferent pathways with two peripheral neurons that travel in series from the central nervous system to the effector organ
true
true or false the autonomic nervous system is also known as the involuntary nervous system
true
true or false the most abundant neurotransmitter in the peripheral nervous system is acetylcholine
true
true or false the parasympathetic nervous system exerts more discrete effects on effector organs that the sympathetic nervous system due to the independence of parasympathetic ganglia
true
Which of the following best describes the general arrangement of the efferent limb of the autonomic nervous system? A) one neuronB) two neurons in parallel C) two neurons in series D) three neurons in series E) three neurons in parallel
two neurons in series
what are swellings of postganglionic autonomic axons from which neurotransmitters are released called
varicosities
what type of channels that are present within the varicosities of autonomic neurons are absent from the axon terminal of other neurons
voltage gated Na+ and K+ channels
the presence of _____________ within varicosities mediate the release of neurotransmitter
voltage-gated Ca2+ channels
