Chapter 11
How does latroxin, the venom of the black widow spider, cause muscle spasms and rigidity. A) It stimulates acetylcholine release from motor neurons. B) It stimulates acetylcholine release from autonomic preganglionic neurons. C) It inhibits acetylcholine release from motor neurons. D) It inhibits the degradation of acetylcholine at all synapses. E) It blocks nicotinic cholinergic receptors.
A) It stimulates acetylcholine release from motor neurons.
What are swellings of postganglionic autonomic axons from which neurotransmitters are released called? A) Varicosities B) Neuromuscular junctions C) Sympathetic trunks D) Parasympathetic chains E) Ganglia
A) Varicosities
What type of channels that are present within the varicosities of autonomic neurons are absent from the axon terminal of other neurons? A) Voltage-gated Na+ and K+ channels B) Voltage-gated Ca2+ and Na+ channels C) Voltage-gated Na+ channels, exclusively D) Voltage-gated Ca2+ channels, exclusively E) Voltage-gated K+ channels, exclusively
A) Voltage-gated Na+ and K+ channels
With respect to their innervation, individual skeletal muscle fibers (cells) are innervated by ________. A) a single motor neuron B) multiple motor neurons C) a single motor neuron and autonomic neuron D) multiple motor neurons and autonomic neurons E) a single motor neuron and multiple autonomic neurons
A) a single motor neuron
Activation of which class of adrenergic receptor will result in calcium release from intracellular stores? A) alpha1 only B) alpha2 only C) beta1 only D) beta2 only E) alpha1, alpha2, and beta1
A) alpha1 only
Where are most of the autonomic nervous system control centers located? A) brainstem B) frontal lobe C) thalamus D) limbic system E) spinal cord
A) brainstem
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
A) skeletal muscles
Which of the following structures of an autonomic neuron is NOT located within the ganglion? A) the cell body of preganglionic neurons B) the terminal axon of preganglionic neurons C) the intrinsic neurons D) the cell body of postganglionic neurons E) the dendrites of postganglionic neurons
A) the cell body of preganglionic neurons
Binding of norepinephrine to what type of receptor will trigger the activation of phospholipase C? A) α1 B) α2 C) β1 D) β2 E) muscarinic
A) α1
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. A) 7521346 B) 7621534 C) 5231746 D) 2153674 E) 4357261
B) 7621534
At rest, what is the relative contribution of the sympathetic and parasympathetic nervous systems to the regulation of homeostasis? A) Only the sympathetic system is active. B) Both systems are active but the parasympathetic predominates. C) Only the parasympathetic system is active. D) Both systems are active but the sympathetic predominates. E) Neither system is active.
B) Both systems are active but the parasympathetic predominates.
What is the graded change in membrane potential that occurs at the motor end plate of skeletal muscle called? A) Inhibitory postsynaptic potential B) End-plate potential C) Muscarinic potential D) Adrenergic potential E) Action potential
B) End-plate potential
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.
B) The end-plate potential is always of sufficient magnitude to depolarize the muscle cell to threshold to initiate an action potential.
Which of the following cranial nerves does NOT include parasympathetic nerves? A) III - oculomotor nerve B) V - trigeminal nerve C) VII - facial nerve D) IX - glossopharyngeal nerve E) X - vagus nerve
B) V - trigeminal nerve
Parasympathetic postganglionic neurons release the neurotransmitter ________; sympathetic postganglionic neurons release the neurotransmitter ________. A) epinephrine : norepinephrine B) acetylcholine : norepinephrine C) norepinephrine : acetylcholine D) acetylcholine : acetylcholine E) norepinephrine : norepinephrine
B) acetylcholine : norepinephrine
What enzyme degrades the neurotransmitter released from varicosities of parasympathetic postganglionic neurons? A) catechol-O-methyltransferase only B) acetylcholinesterase C) monoamine oxidase only D) choline acetyl transferase E) catechol-O-methyltransferase and monoamine oxidase
B) acetylcholinesterase
Which of the following endocrine glands is innervated by sympathetic preganglionic neurons? A) adrenal cortex B) adrenal medulla C) thyroid gland D) anterior pituitary E) pancreas
B) adrenal medulla
Activation of which class of adrenergic receptor decreases the cytosolic levels of cAMP? A) alpha1 only B) alpha2 only C) beta1 only D) beta2 only E) both beta1 and beta2
B) alpha2 only
Dual innervation of organs by the autonomic nervous system refers to the observation that ________. A) two postganglionic sympathetic neurons innervate each target organ B) both sympathetic and parasympathetic neurons innervate most organs C) autonomic innervation involves preganglionic and postganglionic neurons D) autonomic and somatic neurons innervate all organs E) autonomic neurons that innervate each target organ originate from two ganglia
B) both sympathetic and parasympathetic neurons innervate most organs
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 rate D) increased contractile force of the heart E) enhanced mobilization of energy stores
B) enhanced absorption of nutrients
In what class of neuron and within what organelle is the enzyme monoamine oxidase located? A) synaptic vesicles of sympathetic postganglionic neurons B) mitochondria of sympathetic postganglionic neurons C) lysosomes of sympathetic preganglionic neurons D) smooth ER of parasympathetic postganglionic neurons E) Golgi apparatus of parasympathetic postganglionic neurons
B) mitochondria of sympathetic postganglionic neurons
Where on skeletal muscle is the highest density of nicotinic receptors? A) terminal bouton B) motor end plate C) motor unit D) dendrites E) axon hillock
B) motor end plate
Which of the following is NOT a visceral reflex? A) pupillary light reflex B) withdrawal reflex C) vomiting D) urination E) swallowing
B) withdrawal reflex
What is the neurotransmitter released from motor neurons? A) Epinephrine B) Norepinephrine C) Acetylcholine D) Dopamine E) GABA
C) Acetylcholine
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
C) Acetylcholinesterase
Binding of acetylcholine to ________ receptors causes a ________ by opening channels that permit both sodium and potassium to permeate the membrane. A) muscarinic : depolarization B) muscarinic : hyperpolarization C) nicotinic : depolarization D) nicotinic : hyperpolarization E) nicotinic : no change in membrane potential
C) 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
C) one preganglionic neuron sends collaterals to multiple ganglia, affecting multiple postganglionic neurons
The somatic nervous system regulates the activity of ________. A) endocrine organs B) many organs C) skeletal muscle D) the kidneys E) the cardiovascular system
C) skeletal muscle
Which of the following neurons of the efferent branch of the peripheral nervous system does NOT release acetylcholine? A) sympathetic preganglionic neuron B) parasympathetic preganglionic neuron C) sympathetic postganglionic neuron D) parasympathetic postganglionic neuron E) motor neuron
C) sympathetic postganglionic neuron
Which of the following best describes the general arrangement of the efferent limb of the autonomic nervous system? A) one neuron B) two neurons in parallel C) two neurons in series D) three neurons in series E) three neurons in parallel
C) two neurons in series
Which of the following are indicative of the relative release of catecholamines from the adrenal medulla? A) 80% epinephrine : 20% dopamine B) 80% norepinephrine : 20% dopamine C) 80% norepinephrine : 20% epinephrine D) 80% epinephrine : 20% norepinephrine E) 100% acetylcholine
D) 80% epinephrine : 20% norepinephrine
When the body is stressed, what is the relative contribution of the sympathetic and parasympathetic nervous systems to the regulation of homeostasis? A) Only the sympathetic system is active. B) Both systems are active but the parasympathetic predominates. C) Only the parasympathetic system is active. D) Both systems are active but the sympathetic predominates. E) Neither system is active.
D) Both systems are active but the sympathetic predominates.
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.
D) Postganglionic fibers release acetylcholine.
Parasympathetic preganglionic neurons release the neurotransmitter ________; sympathetic preganglionic neurons release the neurotransmitter ________. A) epinephrine : norepinephrine B) acetylcholine : norepinephrine C) norepinephrine : acetylcholine D) acetylcholine : acetylcholine E) norepinephrine : norepinephrine
D) acetylcholine : acetylcholine
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
D) cerebellum
The opening of a cation channel that allows both Na+ and K+ to move through will cause the membrane to ________ because of the ________. A) hyperpolarize : greater K+ electrochemical gradient as compared with Na+ B) hyperpolarize : greater Na+ electrochemical gradient as compared with K+ C) depolarize : greater K+ electrochemical gradient as compared with Na+ D) depolarize : greater Na+ electrochemical gradient as compared with K+ E) not change : same electrochemical gradient for K+ and Na+
D) depolarize : greater Na+ electrochemical gradient as compared with K+
Which of the following does NOT have nicotinic cholinergic receptors? A) skeletal muscle cells B) parasympathetic postganglionic neuron cell bodies C) sympathetic postganglionic neuron cell bodies D) effector organs for the parasympathetic nervous system E) chromaffin cells
D) effector organs for the parasympathetic nervous system
Which of the following physiological responses are associated with elevated sympathetic nervous system activity? A) enhanced digestion B) enhanced absorption of nutrients C) decreased heart rate D) increased contractile force of the heart E) inhibition of cardiovascular function
D) increased contractile force of the heart
Mismatches between vestibular, visual, and proprioceptive sensory inputs activate the autonomic nervous system, leading to symptoms that are characteristic of ________. A) the accommodation reflex B) the vomiting reflex C) fainting D) motion sickness E) the pupillary light reflex
D) motion sickness
Where do the preganglionic neurons of the sympathetic nervous system emerge from the spinal cord? A) thoracic region only B) sacral region only C) lumbar region only D) thoracic and lumbar regions E) lumbar and sacral regions
D) thoracic and lumbar regions
The presence of ________ within varicosities mediate the release of neurotransmitter. A) mechanically-gated Na+ channels B) mechanically-gated Ca2+ channels C) voltage-gated Na+ channels D) voltage-gated Ca2+ channels E) voltage-gated K+ channels
D) voltage-gated Ca2+ channels
The gray ramus is comprised of what fiber type? A) A alpha B) A beta C) A delta D) B E) C
E) C
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.
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.
Parasympathetic neurons from which cranial nerve innervate most of the viscera in the thoracic and abdominal cavities? A) I B) III C) VII D) IX E) X
E) X
Actions at which class of adrenergic receptor generally have excitatory effects? A) alpha1 and alpha2 B) beta1 and beta3 C) beta1, beta2, and beta3 D) alpha1 and beta1 E) alpha1, alpha2, beta1, and beta3
E) alpha1, alpha2, beta1, and beta3
What class of adrenergic receptor activates the enzyme adenylate cyclase? A) alpha1 only B) alpha1 and alpha2 C) beta2 only D) beta1 and beta2 E) beta1, beta2, and beta3
E) beta1, beta2, and beta3
Compared to norepinephrine, epinephrine has a greater affinity for what type of receptor? A) nicotinic B) muscarinic C) alpha1 D) beta1 E) beta2
E) beta2
Where in the central nervous system do the preganglionic neurons of the parasympathetic nervous system originate? A) thoracic region of the spinal cord only B) sacral region of the spinal cord only C) lumbar region of the spinal cord only D) thoracic and lumbar regions of the spinal cord E) brainstem and sacral region of the spinal cord
E) brainstem and sacral region of the spinal cord
What cells of the adrenal medulla release epinephrine? A) alpha cells B) beta cells C) delta cells D) adrenergic cells E) chromaffin cells
E) chromaffin cells
Parasympathetic preganglionic neurons travel in what nerves? A) cranial nerves only B) spinal nerves only C) pelvic nerves only D) cranial and spinal nerves E) cranial and pelvic nerves
E) cranial and pelvic nerves
What area of the brain initiates the fight-or-flight response by producing widespread activation of the sympathetic nervous system? A) brainstem B) cerebellum C) amygdala D) limbic system E) hypothalamus
E) hypothalamus
Within the autonomic ganglia, what are the cells that modulate the flow of information to the target organ called? A) intraganglionic neurons B) ganglionic neurons C) preganglionic neurons D) postganglionic neurons E) intrinsic neurons
E) intrinsic neurons
What cholinergic receptors are coupled to G proteins? A) alpha1 B) alpha2 C) beta2 D) nicotinic E) muscarinic
E) muscarinic
Which class of autonomic nervous system receptors is ionotropic? A) all alpha adrenergic B) all beta adrenergic C) some beta adrenergic but no alpha adrenergic D) muscarinic cholinergic E) nicotinic cholinergic
E) nicotinic cholinergic
The balance between sympathetic and parasympathetic activity is modified primarily by ________. A) voluntary mechanisms B) hunger C) time of day D) body temperature E) the activity of the body
E) the activity of the body
Sympathetic preganglionic neurons exit the spinal nerve via the ________ before they enter the ________. A) white ramus : effector organ B) gray ramus : effector organ C) gray ramus : ganglion of the sympathetic trunk D) ventral root : ganglion of the sympathetic trunk E) white ramus : ganglion of the sympathetic trunk
E) white ramus : ganglion of the sympathetic trunk
What type of receptor agonists are used to treat people suffering from asthma or nasal congestion? A) muscarinic B) nicotinic C) α2 D) β3 E) β2
E) β2