ANS Flashcards
A neuron that synapses in the adrenal medulla is a_________ neuron, and releases the neurotransmitter_________.
preganglionic; acetylcholine (ACh)
Acetylcholine (ACh) always has an excitatory effect.
True or False
False
Acetylcholine (ACh) binds to both muscarinic and nicotinic receptors.
True or False
True
All sympathetic postganglionic adrenergic axon terminals secrete adrenaline.
True or False
False
Autonomic nervous system fibers are involved in all of the following except _________.
maintaining tonicity of the muscles of the neck
Axons of the vagus nerve end very near or within their target organs.
True or False
True
Binding of norepinephrine (NE) to an alpha-adrenergic receptor is usually excitatory, and binding to a beta-adrenergic receptor is usually inhibitory.
True or False
True
Damage to the_________ may affect near vision accommodation.
oculomotor nerve (CN III)
If a cell has image adrenergic receptors, it is sensitive to _________.
norepinephrine (NE)
In response to high blood pressure, stretch receptors called_________ in the walls of arteries carrying blood to the head, will trigger a reflex that causes the heart to_________ its beats per minute.
baroreceptors; decrease
Most autonomic efferent pathways involve one neuron.
True or False
False
Most axons of the parasympathetic nervous system travel in the_________ nerve.
vagus
Most preganglionic axons in the sympathetic nervous system synapse with_________.
10-20 postganglionic neurons
Most preganglionic axons synapse with postganglionic axons in the dorsal root ganglia.
True or False
False
Muscarinic receptors bind_________.
acetylcholine
Preganglionic axons of the autonomic efferent pathway are_________ and secrete_________.
myelinated; acetylcholine (ACh)
Preganglionic axons run from the_________ to the_________.
gray matter; autonomic ganglia
Sympathetic axons arenot associated with_________.
stimulation of digestion
Sympathetic axons arise only from the_________ region(s) of the spinal cord.
thoracic and lumbar
ympathetic effects tend to last_________ than parasympathetic effects. One reason is that_________.
longer; norepinephrine can diffuse into the bloodstream without being broken down
The adrenal medulla secretes mostly _________.
epinephrine (adrenaline)
The autonomic nervous system carries out many somatic reflexes that are crucial to homeostasis.
True or False
False
The autonomic nervous system controls all of the following except the_________.
skeletal muscle in the rectus abdominis
The autonomic nervous system is composed of ganglia in the central nervous system and ganglia in the periphery.
True or False
False
The binding of_________ to a nicotinic receptor of a muscle fiber will_________ it.
acetylcholine; excite
The effect of autonomic fibers on target cells is_________. The effect of somatic fibers on target cells is_________.
excitatory or inhibitory; always excitatory
The enzyme that breaks down norepinephrine (NE) is called _________.
monoamine oxidase (MAO).
The motor pathway of the autonomic nervous system usually involves_________ neurons.
two
The neurotransmitter(s) associated with autonomic ganglia is(are)_________.
acetylcholine (ACh)
The parasympathetic division arises from the_________ regions of the spinal cord.
brain, sacral, and coccygeal
The parasympathetic division stimulates digestion.
True or False
False
The solar plexus is used as a name for the_________.
the celiac and mesenteric ganglia
The sympathetic chain of ganglia is found at the_________ levels of the spinal cord.
cervical, thoracic, lumbar, sacral, and coccygeal
Under normal circumstances, both divisions of the autonomic nervous system are active simultaneously.
True or False
True
Which of the following is not a characteristic of the parasympathetic division of the ANS?
It has short preganglionic axons.
Which of the following is not a feature of the sympathetic division of the ANS?
It has long preganglionic axons.
Which of the following is not a reason that somatic reflexes act faster than visceral reflexes?
The effector pathway in the visceral reflex arc involves more neurons.
Which of the following is true regarding the autonomic nervous system?
Its denervation would cause hypersensitivity.
Which of the following statements is true regarding parasympathetic tone?
It holds the resting heart rate below its intrinsic rate.
Which of the following structures is not associated with the autonomic nervous system?
Oculomotor nerve
Which of the following structures releases neurotransmitter molecules in a paravertebral ganglion?
Sympathetic preganglionic axon
Which one of the following best describes the order of a visceral reflex?
Sensory receptor → afferent nerve fiber → interneuron → efferent nerve fiber → gland
White rami carry_________ neurons, while gray rami carry_________ neurons.
myelinated preganglionic; unmyelinated postganglionic
________ nerve(s) pass(es) throughout sympathetic ganglia without synapsing.
Splanchnic
