Examples of parasympathetic in the following topics:
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- Parasympathetic ganglia are the autonomic ganglia of the parasympathetic nervous system that lie near or within the organs they innervate.
- Parasympathetic ganglia are the autonomic ganglia of the parasympathetic nervous system, blue fibers).
- The exceptions are the four paired parasympathetic ganglia of the head and neck.
- The parasympathetic nervous system, shown in blue, is a division of the autonomic nervous system.
- Describe features of the parasympathetic division of the autonomic nervous system
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- The parasympathetic nervous system regulates organ and gland functions during rest and is considered a slowly activated, dampening system.
- The parasympathetic nervous system (PSNS, or occasionally PNS) is one of the two main divisions of the autonomic nervous system (ANS).
- The sympathetic and parasympathetic divisions typically function in opposition to each other.
- The parasympathetic nervous system may also be known as the parasympathetic division.
- The parasympathetic nervous system, shown in blue, is a division of the autonomic nervous system.
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- The autonomic nervous system (ANS) contains two subdivisions: the parasympathetic (PSNS) and sympathetic (SNS) nervous systems.
- Sympathetic and parasympathetic divisions typically function in opposition to each other.
- The parasympathetic division functions with actions that do not require immediate reaction.
- Many think of sympathetic as fight or flight and parasympathetic as rest and digest or feed and breed.
- Distinguish between the parasympathetic and sympathetic subsystems of the autonomic nervous system
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- The sympathetic and parasympathetic autonomic nervous systems cooperatively modulate internal physiology to maintain homeostasis.
- Sympathetic and parasympathetic divisions typically function in opposition to each other.
- The parasympathetic division functions with actions that do not require immediate reaction.
- Consider sympathetic as fight or flight and parasympathetic as rest and digest or feed and breed.
- Some typical actions of the sympathetic and parasympathetic systems are listed below.
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- Sympathetic preganglionic fibers tend to be shorter than parasympathetic preganglionic fibers because sympathetic ganglia are often closer to the spinal cord while parasympathetic preganglionic fibers tend to project to and synapse with the postganglionic fiber close to the target organ.
- The parasympathetic division has craniosacral outflow, meaning that the neurons begin at the cranial nerves (CN3, CN7, CN9, CN10) and sacral (S2–S4) spinal cord.
- The parasympathetic division (craniosacral outflow) consists of cell bodies from one of two locations: the brainstem (cranial nerves III, VII, IX, X) or the sacral spinal cord (S2, S3, S4).
- Whereas in the parasympathetic division there is a divergence factor of roughly 1:4, in the sympathetic division there can be a divergence of up to 1:20.
- The parasympathetic division has craniosacral outflow, meaning that the neurons begin at the cranial nerves (CN3, CN7, CN9, CN10) and the sacral (S2–S4) spinal cord.
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- The two main categories are: sympathetic ganglia and parasympathetic ganglia.
- Parasympathetic ganglia are the autonomic ganglia of the parasympathetic nervous system.
- The axons of presynaptic parasympathetic neurons are usually long.
- As a result, the postsynaptic parasympathetic nerve fibers are very short.
- Parasympathetic ganglia of the head (shown as red circles) help supply all parasympathetic innervation to the head and neck.
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- The vagus nerve (cranial nerve X) is responsible for parasympathetic output to the heart and visceral organs.
- The dorsal nucleus of vagus nerve: Sends parasympathetic output to the viscera, especially the intestines.
- The nucleus ambiguus: Sends parasympathetic output to the heart (slowing it down).
- The vagus nerve supplies motor parasympathetic fibers to all the organs, except the suprarenal (adrenal) glands, from the neck down to the second segment of the transverse colon.
- Parasympathetic
innervation of the heart is partially controlled by the vagus nerve and is shared
by the thoracic ganglia.
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- It is classically divided into two subsystems: the parasympathetic nervous system (PSNS) and sympathetic nervous system (SNS).
- The effect of parasympathetic stimulation is to increase activity in the entire enteric nervous system The proximal half of the nervous system is innervated from the cranial parasympathetic nerve fibers via the vagal nerve.
- The distal half is innervated via the Sacral Parasympathetic nerves.
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- In the parasympathetic division, they are cholinergic and use acetylcholine as their neurotransmitter.
- The axons of presynaptic parasympathetic neurons are usually long.
- As a result, the postsynaptic parasympathetic nerve fibers are very short.
- In the cranium, preganglionic fibers (cranial nerves III, VII, and IX) usually arise from specific nuclei in the central nervous system (CNS) and create a synapse at one of four parasympathetic ganglia: ciliary, pterygopalatine, otic, or submandibular.
- The parasympathetic nervous system uses acetylcholine (ACh) as its chief neurotransmitter, although peptides (such as cholecystokinin) may act on the PSNS as a neurotransmitter.
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- The parasympathetic
division functions with actions that do not require immediate reaction.
- Some typical actions of the sympathetic and
parasympathetic systems are listed below.
- Acetylcholine
is the preganglionic neurotransmitter for both divisions of the ANS, as well as
the postganglionic neurotransmitter of parasympathetic neurons.
- In the parasympathetic
system, ganglionic neurons use acetylcholine as a neurotransmitter to stimulate
muscarinic receptors.
- The functions
of the parasympathetic and sympathetic nervous systems are detailed.