ANS of Abdomen and Pelvis Flashcards
By what parameters can the visceral motor system be distinguished from the somatic nervous system?
- Effector
- Location in CNS
- Organization of peripheral pathway
The ANS regulates the activities of _________, _______, and _________.
smooth muscle, cardiac muscle & glands
NOTE: Any nerve innervating these structures is part of the ANS, it receives a general vsiceral efferent innervation.
There are 2 GVE fibers located between the effector and the CNS. Where are the cell bodies of the GVE fibers located?
- The first neuron is located in the CNS and is called preganglionic neuron
- The second neuron is located in a PNS ganglion and is called the postganglionic neuron
NOTE: There is 1 GSE fiber in the somatic pathway between the CNS and effector (skeletal muscle)..
How can sympathetic and parasympathetic systems be distinguished?
By the location of their preganglionic neurons
The sumpathetic nervous system originates from spinal cord levels ________.
T1-L2
Where does the parasympathetic nervous system originate?
Cranial nerves 3,7,9,10
S2-S4
Most organs and glands receive dual innervation from the sympathetic and parasympatheric systems. Which organ only receive innervation from the sympathetic nervous system and not the parasympathetic nervous system?
Skin
- Arredctor pili muscles
- Blood vessels
- Glands
The _________ (parasympathetic/sympathetic) nervous system has a diverging or global organization with a single preganglionic neuron synapsing with many postganglionic neurons.
Sympathetic
NOTE: The “whole”body is activated during a sympathetic response.
The (parasympathetic/sympathetic) nervous system has a discrete organization with a single preganglionic neuron synapsing with one or two postganglionic neurons.
Parasympathetic
*More specific
What two types of ganglion carry the soma of postganglionic nerve fibers? Why are they located?
Paravertebral
- Found on either side of the vertebral column
Prevertebral
- Found anterior to the vertebral column in the _abdominal region (_seen as we dissect the posterior abdominal wall)
Which preganglionic parasympathetic fibers innnervate the foregut, midgut, and hindgut respectively?
Foregut: Vagus
Midgut: Vagus
Hindgut: Sacral pelvic splanchnic nerves
Where are the soma of postganglionic parasympathetic fibers of the GI tract located?
- Submucosal ganglia
- Myenteric ganglia
NOTE: In opposition to sympathetic postganglionic fibers, parasympathetic postganglionic fibers are short
Label
Label
Hirschsprung Disease is associated with what conditions?
Constipation
Slow growth
Megacolon
Down Syndrome
Waardenburg syndromes
NOTE: Hirschsprung Disease results from failure of neural crest to form submucosal and myenteric plexuses.
Symptoms of Hirshsprung Disease
- Swelling in the area around the belly
- Vomiting with a greenish-brown vomitus
- Constipation
- Flatulence
- Diarrhea
- Failure to gain weight
- Severe fatigue
Which nerves supply the abdominal cavity with visceral sensory and visceral motor axons?
- Vagus
-
Thoracic splanchnic nerves (sympathetic)
- Greater
- Lesser
- Least
- Lumbar splanchnic nerves
- Sacral splanchnic nerve (sympathetic)
- Pelvic splanchnic nerves (parasympathetic)
What are the spinal cord levels of the greater, lesser, and least splanchnic nerves, respectively?
- Greater splanchnic nerve (T5-T9)
- Lesser splanchnic nerve (T10-T11)
- Least splanchnic nerve (T12)
What fiber types are found in the greater, lesser, and least splanchnic nerves?
- Preganglionic sympathetic
- GVA (carry sensation of pain back to the spinal cord
The lumbar sympathetic ganglia come off of the ________.
Sympathetic chain
Components of the aortic plexus
- Celiac plexus
- Intermesenteric plexus
- Superior hypogastric plexus
- Hypogastric nerves
- Inferior hypogastric plexus
Where is the intermesenteric plexus located?
Between the superior mesenteric artery and inferior mesenteric artery
The inferior hypogastric plexus innervates which organs?
Organs located in the pelvic cavity
The fibers that we talk about in terms of the sympathetic system, coming from the splanchnic nerves are ____________.
Preganglionic
NOTE: This means that these fibers have to synapse somewhere. If they synapse in the sympathetic chain those fibers will go to the body wall or the limbs. If they go through the sympathetic chain, they’ll syanpse in the prevertebral ganglion.
Where does the greater splanchnic nerve terminate?
At the celiac trunk
Where is the superior mesenteric ganglion located?
At the base of the mesenteric artery
Where is the aorticorenal ganglion located?
At the bifurcation of the renal artery from the aorta
The greater splanchnic nerve terminates at the _______ ganglion.
Celiac
What are the prevertebral ganglion located in the abdomen?
- Celiac trunk
- Superior mesenteric ganglion
- Aorticorenal ganglion
- Inferior mesenteric ganglion
The lesser splanchnic nerve terminates at the _________ ganglion.
Aorticorenal ganglion
REMEMBER: The aorticorenal ganglion and the superior mesenteric ganglion are located very close together and so are difficult to distinguish.
Least splanchnic nerve terminates into the ___________.
Renal plexus
Different spinal cord levels that innervate the GI tract
Flow of nerve signals to the pancreas
- Preganglionic neuron
- Spinal nerve T10
- White communicating rami
- Lesser splanchnic nerve
- Aorticorenal ganglion (S.mesenteric)
The appendicular artery is a branch of the ________.
Iliocolic artery
*The iliocolic artery is a branch of the superior mesenteric artery
Which type of fibers are found in the appendicular plexus?
Postganglionic sympathetic fbers that synapse in aorticorenal ganlgion
The chromaffin cells of the adrenal medulla receive ______ innervation.
Preganglionic sympathetic innervation
NOTE: These cells are modified post-ganglionic sympathetic neurons. They release epinephrine and norepinephrine directly into the blood
Function of GVA fibers
- Visceromotor reflexes
- Relaying pain from viscera
- Creating an awareness of “self”
___________, ___________, and ________ can produce an imbalance of the ANS.
Severe trauma, chronic stress, and PTSD
*This can lead to overactive sympathetics or a shutdown of sympathetics
