Term
| The autonomic NS is a system of -- neurons |
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Definition
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Term
What does the ANS innervate, Regulate, and the general?
It includes what divisions? |
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Definition
innervates smooth muscle, cardiac muscle and glands
Regulates visceral functions (HR, BP, digestion, urination)
The general visceral motor division of the PNS
includes the Sympathetic and Parasympathetic divisions |
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Term
Compare ANS and Somatic Motor system:
Neurons
Conduction speed |
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Definition
SMS- 1 motor neuron extends from CNS to skeletal muscle and exons are well myelinated, rapid impulses
ANS- Chain of 2 or more motor neurons and synapse in ganglia, conduction speed is slow due to thinly or unmeylinated axons |
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Term
| What are the neurons called that synapse in a ganglia? |
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Definition
Preganglionic neuron
Postganglionic neuron |
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Term
| The sympathetic and parasympathetic divisions innervate and cause: |
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Definition
| innervate mostly the same structures but cause opposite effects |
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Term
| What does the Sympathetic NS do? |
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Definition
Fight, flight, or fright
-activated during exercise, excitement, and emergencies |
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Term
| What does the parasympathetic NS do? |
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Definition
rest and digest
-concerned w/saving energy |
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Term
| What are the 4 anatomical differences between symp and parasymp divisions? |
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Definition
emerge from different regions of CNS
different NT released by each postganglionic axon
Length of postganglionic fibers
Branching of axons |
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Term
| Where does the sympathetic NS emerge from the CNS? |
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Definition
T1-L2 regions of spinal cord
aka toracolumbar division* |
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Term
| Where does the parasym NS emerge from CNS? |
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Definition
emerge from brain stem and sacral region of spinal cor
aka craniosacral division* |
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Term
| What NT does symp release by postganglionic axons? |
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Definition
| most release norepinephrine |
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Term
| What NT does parasymp release by postganglionic axons? |
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Definition
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Term
| What is the length of postganglionic fibers in symp? |
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Definition
| long postganglionic fibers |
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Term
| What is the length of postganglionic fibers in parasymp? |
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Definition
| short postganglionic fibers (ganglia are on or near target organs) |
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Term
| How do axons branch in symp? |
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Definition
| highly branched- they influence many organs |
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Term
| How do axons branch in parasymp? |
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Definition
| few branches- localized effects |
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Term
| What is the cranial vs sacral outflow of the parasympathetic division? |
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Definition
Cranial-comes from brain, innervates organs of the head, neck, thorax, and abs
Sacral-
supplies remaining abdominal and pelvic organs |
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Term
| For the cranial outflow in the Parasymp, how do preganglionic fibers run? |
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Definition
Oculomotor Nerve (3)-smooth muscle of eye
Facial Nerve (7)- salivary glands, lacrimal glands
Glossopharyngeal Nerve (4)- parotid salivary glands
Vagus Nerve (10)- many visceral organs in thorax and abdomen |
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Term
| Where are cell bodies located in the cranial outflow of the parasymp? |
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Definition
| located in cranial nerve nuclui in brain stem |
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Term
| What is the path of the vagus nerve? |
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Definition
autonomic nerve plexuses: network of autonomic nerves-
cardiac plexus
pulmonary plexus
esophageal plexus
celiac plexus
superior mesenteric plexus |
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Term
| What is the Sacral outflow of the Parasymp? |
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Definition
emerges from S2-S4
Innervates organs of the pelvis and lower abdomen
Preganglionic cell bodies are located in visceral motor region of spinal gray matter
Axons run in ventral roots to ventral rami-branch from rami and form splanchnic nerves |
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Term
What is the basic organization of the Symp?
emerges-
pregang fibers from-
supplies-
number of ganglia compared to parasymp- |
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Definition
Emerges from T1-L2
Preganglionic fibers from the lateral gray horn*
Supplies visceral organs and structures of superficial body regions
Contains more ganglia than parasymp divsision |
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Term
Where is the Sympathetic trunk ganglia? How are they linked?
What do they join? |
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Definition
located on both sides of vertebral column
Linked by short nerves into symp trunks
joined to ventral rami by white and gray rami commicantes |
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Term
| How are symp trunk ganglia joined to ventral rami? |
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Definition
By White and Gray rami communicantes:
Ventral Rami-> White rami to ganglion-> grey rami back to ventral rami-> branches form autonomic nerevs |
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Term
| What do splanchnic nerves to prevertebral ganglia pass through? |
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Definition
| axons pass thru trunk ganglia |
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Term
| Symp trunk ganglia numbers compared to spinal nerves? |
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Definition
| fushion of ganglia= fewer than spinal nerves |
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Term
Prevertebral ganglia-
arranged:
Occur in:
Location around vertebral column:
Main ganglia: |
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Definition
unpaired, not segmentally arranged
occur only in abdomen and pelvis
lie anterior to vertebral column
Main ganglia: celiac, superior mesenteric, inferior mesenteric, inferior hypogastric |
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Term
Symp Pathways to Head
Origins:
fibers direction and synapse
postganglionic travels: |
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Definition
spinal cord T1-T4
Fibers ascend in symp trunk
synapse in superior cervical ganglion
postgang fibers associate w/large arteries
caried by these structures to:
glands, smooth muscle, vessels thruout head |
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Term
Symp Pathways to Thoracic organs
origin:
synapse location:
postgangl fibers:
Functions |
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Definition
Origniate spinal cord T1-T6
Some fibers synapse in nearest symp trunk ganglion, others are less direct, some pass thru ganglion and either ascend or descend to neighboring ganglia
Postgang fibers run directly to the organs supplied
Function: increase HR, dialate bronchioles, dilate blood vessels to heart wall, inhibit the muscle gland in esophagus |
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Term
Symp pathways to Abdominal Organs
Origin:
Where do they pass through, travel in, and synapse at?
Inhibit: |
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Definition
Pregang fibers originate in spinal cord (T5-L2)
Pass through adjacent symp trunk ganglia
Travel in thoracic splanchnic nerves
synapse in prevertebral ganglia on the abdominal aorta
celiac and superior mesentric ganglia
inhibit activity of muscles and glands in visceral organs |
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Term
Symp pathways to pelvic organs:
Fibers origniate:
Where do fibers synapse:
What do postganglionic fibers do? |
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Definition
fibers originate in spinal cord (T10-L2)
Somes fibers synapse in sympathetic trunk, and others synapse in prevertebral ganglia
Postgang fibers proceed from plexuses to pelvic organs |
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Term
Roles of Adrenal Medulla in Symp NS
what is it:
consists of:
Secretes:
Is stimulated by: |
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Definition
Adrenal Medulla is the major organs of the Symp NS
-consists largest symp ganglia
Secretes great quantites of epinephrine (adrenaline)
Stimulated to secrete by preganglionic symp fibers |
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Term
| What is the central control of the ANS? |
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Definition
Brain Stem and Spinal Cord Control ANS
-Reticular formation exerts most direct influence w/ Medulla Oblongata and Periaquductal gray matter
-Hypothalamus is the main integration center for ANS |
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