Tema 14

Question 1

Autonomic NS

Answer 1

The portion of the nervous system that controls organs and glands
Divided in:
*Sympathetic Nervous System
*Parasympathetic Nervous System
*Enteric Nervous System

Question 1

Sympathetic NS

Answer 1

Preganglionic sympathetic nerve fibers go from the spinal nerves to the sympathetic chord where they can
1) synapse and continue as postganglionar n.
2) it can not synapse in paravertebral chord and synapse in pre vertebral chain
3) it can move up and down in the paravertebral chord and synapse
They continue through the splanchnic nerves, and finally into the two adrenal medullae; which secrete epinephrine and norepinephrine into the blood stream.

Question 2

Parasympathetic NS

Answer 2

Parasympathetic fibers leave the CNS through cranial nerves III, VII, IX, and X the sacral nerves
About 75% of all parasympathetic nerve fibers are in the vagus nerves (cranial nerve X), passing to the entire thoracic and abdominal regions of the body.
The vagus nerves supply parasympathetic nerves to the heart, lungs, esophagus, stomach, entire small intestine, proximal half of the colon, liver, gallbladder, pancreas, kidneys, and upper portions of the ureters.

Question 3

Preganglionic vs Postganglionic

Answer 3

Both para- and sympathetic nervous system have pre and postganglinic neurons.

PARASYMPATHETIC
The preganglionic fibers pass uninterrupted all the way to the organ that is to be controlled, the postganglionic neuron is in the wall of the organ.The preganglionic fibers synapse with these.

SYMPATHETIC
Cell bodies of the sympathetic postganglionic neurons are almost always located in the ganglia of the sympathetic chain or in various other discrete ganglia in the abdomen

*Sympathetic: short pre, long post
*Parasympathetic: long pre, short post

Question 4

Enteric NS

Answer 4

formed by submucosal plexus (in submucosa) and myenteric plexus (in between 2 muscle)

Question 5

Somatic vs Autonomous SN

Answer 5

Voluntario
Músculo esquelético
Una neurona eferente
Los axones liberan acetilcolina
Siempre las neuronas son excitadoras
Se encuentra controlado por la corteza cerebral

Involuntario
Se da en el músculo liso, cardíaco y glándulas
Varias neuronas eferentes
Los axones liberan acetilcolina o noradrenalina
Puede ser excitador o inhibidor
Está controlado por los centros
homeostáticos del cerebro (hipotálamo,protuberancia y bulbo)