Lymphatic Drainage + Innervation of the FOREGUT?
CELIAC TRUNK - Sympathetic: Celiac ganglion - Parasympathetic: Vagus (X) .. cranial nerve 10
Lymphatic Drainage + Innervation of the MIDGUT?
CRANIAL MESENTERIC ARTERY - Symp: Cranial Mesenterig g. - Para: Vagus (X)
Lymphatic Drainage + Innervation of the HINDGUT?
CAUDAL MESENTERIC ARTERY - Symp: Caudal Mesenteric g. - Para: Pelvic Splanchnic nn.
Autonomic Nervous System has 2 neuron divisons called:
- Sympathetic outflow- long postganglionic axon
- Parasympathetic outflow- very short postganglionic axon (often present in wall of organ being innervated)
What is the KEY DIFFERENCE* between the 2 neuron system?
NO PARASYMPATHETIC INNERVATION TO THE BODY WALL
Sympathetic vs Parasympathetic effects in the abdomen?
Sympathetic: Decreased activity of GI tract = slow(er) inhibition of digestion and slows rate of absorp
Parasympathetic: Increased activity of GI tract = increase motility and secretion, and absorption
What does the enteric nervous system regulate?
GI tract as a separate component of the ANS, acting as a local reflex response
The digestive tract has as many neurons as the _______
Sympathetic and parasympathetic nerve fibers modulate the ____
_____ and ____ plexi regulate bowel musculature and are located btwn ____ and ____ smooth muscle layers of the GI tract
Myenteric and submucosal plexi;
Located btwn inner circular and outer logitudinal
Enteric nervous system: Waves of contraction and relaxation in the bowel are due to? (2)
- Mechanoreceptors monitoring stretch
- Enteric nervous system responding in a reflexive manner
ENS is INHIBITED by _____ and EXCITED by ___?
Inhibited by sympathetic nerve fibers
Excited by parasympathetic nerve fibers
Parasympathetic nerve fibers are innervated by (2)?
Vagus nerve (CN X) and splanchic nerves (anatomically responsible for delivering axons to abdomen) from sacral spinal cord
What is distension during peristalsis of colon?
Sensory neuron synpases on excitatory motorneurons proximal to the bolus and contracts muscle fibers
What is relaxation during peristalsis of colon?
Sensory neuron synpases on inhibitory interneurons distal to the bolus and allows muscle fibers to relax
What structures do the Foregut, midgut, and hindgut nerves innervate?***
Foregut --> stomach, duodenum, pancreas, liver, spleen, gallbladder
Midgut--> duodenum, jejunum, ileum, cecum, part of colon
Hindgut --> part of colon, rectum, anal canal
Splanchnic Nerves Deliver Preganglioncs:
- Foregut Sympathetic Eg, Midgut Sympathetic Eg. Fore-midgut parasympathetic Eg.
Abdominopelvic Autonomic Plexus in Carnivorans: what do they do?
Greater Splanchnic nn, Celiac ganglia, Lumbar splanchnic nn, Cranial mesenteric ganglion, Cadual mesenteric ganglion
Carnial mesenteric ganglia/plexus innervates what organ?
Liver- hepatic artery
Lesions of vagal supple in bovines; vagus regulated functions (6)?
1. Ruminoreticular contraction
2. Omasal cycle
5. Reflex closure of reticular groove
6. Abomasal motility and secretion
What is vagotomy?
Stops ruminoreticular activity, recovers eventually (1 vagus artery)
What is fatal omasal paralysis*?
Lesions to both vagal trunks, ruminoreticulum distends and backs up
Potential causes of fatal omasal paralysis or vagotomy?
Lesions, foreign bodies, volvulus (nails)