62 terms

:) Chapter 15 ANS

The autonomic nervous system carries out many somatic reflexes that are crucial to homeostasis.
Both divisions of the autonomic nervous system are normally active simultaneously.
The autonomic nervous system is composed of ganglia in the central nervous system and ganglia in the periphery.
Most autonomic efferent pathways involve one neuron.
The parasympathetic division stimulates digestion.
Most preganglionic fibers synapse with postganglionic fibers in the dorsal root ganglia.
All preganglionic fibers pass through the sympathetic chain of ganglia synapsing at least once there.
The adrenal medulla is a modified sympathetic ganglion.
Fibers of the vagus nerve end very near or within their target organs.
The autonomic effect on a target cell depends only on the neurotransmitter reaching that target cell.
Most sympathetic postganglionic adrenergic fibers secrete adrenaline.
Acetylcholine (ACh) binds to both muscarinic and nicotinic receptors.
Acetylcholine (ACh) always has an excitatory effect.
Binding of norepinephrine (NE) to an alpha-adrenergic receptor is usually excitatory, and binding to a beta-adrenergic receptor is usually inhibitory.
All autonomic output originates in the central nervous system.
skeletal muscle in the rectus abdominis
The autonomic nervous system controls all of the following except the
maintaining tonicity of the muscles of the neck.
Autonomic nervous system fibers are involved in all of the following except
sensory receptor → afferent nerve fiber → interneuron → efferent nerve fiber → gland
Which one of the following best describes the order of a visceral reflex?
holds the resting heart rate below its intrinsic rate.
Parasympathetic tone
Sympathetic nerve fibers are not associated with situations involving.
Autonomic tone
___ is the background rate of sympathetic and parasympathetic activity.
acetylcholine (ACh).
The neurotransmitter(s) associated with autonomic ganglia is(are)
excitatory or inhibitory; always excitatory
The effect of autonomic fibers on target cells is ___, and/whereas the effect of somatic fibers is ___.
denervation would cause hypersensitivity.
Autonomic nervous system
baroreceptors; decrease
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.
The motor pathway of the autonomic nervous system usually involves __ neurons.
gray matter to autonomic ganglia.
Preganglionic fibers run from
myelinated; acetylcholine (ACh)
Preganglionic fibers of the autonomic efferent pathway are ____ and secrete ____.
effector organs in the somatic reflex are closer to the spinal cord
Somatic reflexes act faster than visceral reflexes. These are all reasons for this except
the vagus nerve.
Most fibers of the parasympathetic nervous system travel in
thoracic and lumbar
Sympathetic fibers arise only from the ____ region(s) of the spinal cord.
cervical, thoracic, lumbar, sacral, and coccygeal
The sympathetic chain of ganglia (paravertebral ganglia) is found at the ___ levels of the spinal cord.
it has long preganglionic fibers.
These are all features of the sympathetic division except
it has short preganglionic fibers.
These are all characteristics of the parasympathetic division except
the sympathetic nervous system having a relative widespread effect.
Most preganglionic fibers in the sympathetic nervous system synapse with 10 to 20 postganglionic neurons. This results in
either the celiac and mesenteric ganglia or with celiac ganglia only.
The solar plexus is used as a name for
epinephrine (adrenaline).
The adrenal medulla secretes mostly
vagus nerve (CN X)
Which nerve(s) carries the most parasympathetic fibers?
brain and sacral
The parasympathetic division arises from the ___ region(s) of the spinal cord.
oculomotor nerve (CN III)
Damage to the ___ may affect near vision accommodation.
myelinated preganglionic; unmyelinated postganglionic
White rami carry ____ neurons, while gray rami carry ____ neurons.
its reflex arcs are associated with the spinal cord.
These are all characteristics of the enteric nervous systems except
If a cell has α1 adrenergic receptors, it is sensitive to
adrenal medulla activity.
All of the following are under dual control of the ANS except
decrease heart rate.
Propranolol, a beta-blocker, is typically used to
Which of the following is more effective in producing bronchodilation?
Muscarinic receptors bind
acetylcholine; excite
The binding of ___ to a nicotinic receptor of a muscle fiber will ___ it.
muscarinic receptor
Atropine is sometimes used to dilate the pupil for eye examination. Which receptor would atropine block?
gastrointestinal motility.
Antagonistic effects of the two divisions of the autonomic nervous system are exemplified in the control of
___ is an example of the cooperative effect between the two autonomic nervous system divisions.
nitric oxide (NO).
Sympathetic fibers do not release
longer; norepinephrine can diffuse into the bloodstream without being broken down
Sympathetic effects tend to last ___ than parasympathetic effects. One reason is that ___.
monoamine oxidase (MAO)
This enzyme breaks down norepinephrine (NE).
preganglionic; acetylcholine (ACh)
A neuron that synapses in the adrenal medulla is a ____ neuron, and releases the neurotransmitter ____.
decrease the amount of NE destroyed and may be used as an antidepressant.
Drugs that are monoamine oxidase (MAO) inhibitors would most likely
A possible explanation for the effect of caffeine is that it blocks the receptor for a neuromodulator in the brain called _____, which inhibits ACh release by cholinergic neurons.
postganglionic neurons of the sympathetic division
Which one of the following is made up of primarily adrenergic fibers?
62. The ___ is an especially important center of autonomic control.
spinal cord.
Autonomic function receives input from all these except
___ nerve(s) pass(es) throughout sympathetic ganglia without synapsing.
reduced urinary output
Which of the following is associated with the "flight or fight" reaction?