Parasympathetic Nervous System
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Anatomy › Parasympathetic Nervous System
Which cranial nerves are part of the visceral efferent parasympathetic in the peripheral nervous system (PNS)?
III, VII, IX, and X
III, VII, VIII, and IX
VII, IX, and X
VII and IX
III, VII, IX, and XI
Explanation
The cranial nerves that are part of the visceral efferent parasympathetic in the PNS are III, VII, IX, and X. Cranial nerve III (oculomotor) travels to the ciliary ganglion and supplies the pupil of the eye for constriction. Cranial nerve VII (facial) travels to the pterygomandibular and submandibular ganglion and supplies the lacrimal and salivary glands. Cranial nerve IX (glossopharyngeal) travels to the otic ganglion and supplies the Parotid gland. Lastly, cranial nerve X (vagus) travels to the Prevertebral plexus and thoracic plexus in order to supply the gut, heart, and enteric system.
Atropine is a molecule that is an antagonist to muscarinic cholinergic receptors. Based on your knowledge of autonomic nervous system physiology, how would you expect the pupils to respond to topical administration of atropine?
You will observe mydriasis (pupil dilation)
You will observe miosis (pupil constriction)
There will be no change in pupil size because the pupils do not have muscarinic receptors
The iris sphincter muscles would experience a relaxed paralysis
The iris sphincter muscles would experience a contracted paralysis
Explanation
The pupillary sphincter muscles contain muscarinic cholinergic receptors that help the eyes to respond to parasympathetic tone. When this parasympathetic signal is blocked (antagonized) via atropine, you will observe a "sympathetic response" at the level of the pupil. In this scenario, you would observe the sympathetic response of pupil dilation. Hint: "aTROP'ine" and "seeing a TROPical setting" both cause your pupils to dilate nice and wide!
How is the parasympathetic branch of the autonomic nervous system organized?
Long preganglionic fiber, short postganglionic fiber
Short preganglionic fiber, long postganglionic fiber
Short preganglionic fiber, short postganglionic fiber
Long preganglionic fiber, long postganglionic fiber
Explanation
Cell bodies of preganglionic neurons are located in the central nervous system (CNS); they synapse onto autonomic ganglia. Parasympathetic ganglia are located in or near the effector organs giving them long preganglionic fibers and short postganglionic fiber. Sympathetic ganglia are located in the paravertebral chain, thus they have short preganglionic fibers and long postganglionic fibers.
How is the parasympathetic branch of the autonomic nervous system organized?
Long preganglionic fiber, short postganglionic fiber
Short preganglionic fiber, long postganglionic fiber
Short preganglionic fiber, short postganglionic fiber
Long preganglionic fiber, long postganglionic fiber
Explanation
Cell bodies of preganglionic neurons are located in the central nervous system (CNS); they synapse onto autonomic ganglia. Parasympathetic ganglia are located in or near the effector organs giving them long preganglionic fibers and short postganglionic fiber. Sympathetic ganglia are located in the paravertebral chain, thus they have short preganglionic fibers and long postganglionic fibers.
Atropine is a molecule that is an antagonist to muscarinic cholinergic receptors. Based on your knowledge of autonomic nervous system physiology, how would you expect the pupils to respond to topical administration of atropine?
You will observe mydriasis (pupil dilation)
You will observe miosis (pupil constriction)
There will be no change in pupil size because the pupils do not have muscarinic receptors
The iris sphincter muscles would experience a relaxed paralysis
The iris sphincter muscles would experience a contracted paralysis
Explanation
The pupillary sphincter muscles contain muscarinic cholinergic receptors that help the eyes to respond to parasympathetic tone. When this parasympathetic signal is blocked (antagonized) via atropine, you will observe a "sympathetic response" at the level of the pupil. In this scenario, you would observe the sympathetic response of pupil dilation. Hint: "aTROP'ine" and "seeing a TROPical setting" both cause your pupils to dilate nice and wide!
Which cranial nerves are part of the visceral efferent parasympathetic in the peripheral nervous system (PNS)?
III, VII, IX, and X
III, VII, VIII, and IX
VII, IX, and X
VII and IX
III, VII, IX, and XI
Explanation
The cranial nerves that are part of the visceral efferent parasympathetic in the PNS are III, VII, IX, and X. Cranial nerve III (oculomotor) travels to the ciliary ganglion and supplies the pupil of the eye for constriction. Cranial nerve VII (facial) travels to the pterygomandibular and submandibular ganglion and supplies the lacrimal and salivary glands. Cranial nerve IX (glossopharyngeal) travels to the otic ganglion and supplies the Parotid gland. Lastly, cranial nerve X (vagus) travels to the Prevertebral plexus and thoracic plexus in order to supply the gut, heart, and enteric system.
Which of the following nerves carries parasympathetic nerve fibers?
Vagus nerve
White ramus communicans
Sympathetic trunk
C3, C4, and C5 spinal nerves
Explanation
The vagus nerve (CNX) provides the heart and digestive tract with parasympathetic ("rest and digest") control.
Cranial nerves with associated parasympathetic activity include CN III, VII, IX, and X. The sympathetic trunk and the white ramus communicans are associated with the sympathetic nervous system.
Which of the following nerves carries parasympathetic nerve fibers?
Vagus nerve
White ramus communicans
Sympathetic trunk
C3, C4, and C5 spinal nerves
Explanation
The vagus nerve (CNX) provides the heart and digestive tract with parasympathetic ("rest and digest") control.
Cranial nerves with associated parasympathetic activity include CN III, VII, IX, and X. The sympathetic trunk and the white ramus communicans are associated with the sympathetic nervous system.
What neurotransmitter is used by the preganglionic and postganglionic neurons of the parasympathetic nervous system, respectively?
preganglionic uses acetylcholine; postganglionic uses acetylcholine
preganglionic uses norepinephrine; postganglionic uses acetylcholine
preganglionic uses norepinephrine; postganglionic uses norepinephrine.
preganglionic uses serotonin; postganglionic uses acetylcholine.
The parasympathetic system only has a preganglionic neuron, which uses acetylcholine as its neurotransmitter.
Explanation
The parasympathetic nervous system acts oppositely to the sympathetic nervous system, by signaling the activation of relaxation and digestion (increased blood flow to digestive system, pupil constriction, lower heart rate and blood pressure). The parasympathetic nervous system signal is transmitted to the body through a preganglionic neuron and a postganglionic neuron. Both of these use acetylcholine in the parasympathetic nervous system.
What neurotransmitter is used by the preganglionic and postganglionic neurons of the parasympathetic nervous system, respectively?
preganglionic uses acetylcholine; postganglionic uses acetylcholine
preganglionic uses norepinephrine; postganglionic uses acetylcholine
preganglionic uses norepinephrine; postganglionic uses norepinephrine.
preganglionic uses serotonin; postganglionic uses acetylcholine.
The parasympathetic system only has a preganglionic neuron, which uses acetylcholine as its neurotransmitter.
Explanation
The parasympathetic nervous system acts oppositely to the sympathetic nervous system, by signaling the activation of relaxation and digestion (increased blood flow to digestive system, pupil constriction, lower heart rate and blood pressure). The parasympathetic nervous system signal is transmitted to the body through a preganglionic neuron and a postganglionic neuron. Both of these use acetylcholine in the parasympathetic nervous system.