Ch 23 Digestive System

Pepsin

A protein digesting enzyme that is activated by hydrochloric acid in the stomach

Pancreatic juice

Approximately 1200 to 1500 mL Produced daily. Consists mainly of water and contains enzymes in a lecture lights primarily bicarbonate ions. The high pH helps neutralize acid it came into the duodenum and provide optimal environment or intestinal and pancreatic enzymes the pancreatic enzymes include Proteases amylase lipases nuclease

Vasoactive intestinal peptide

Cite a production is enteric neurons. Stimulus for production is kind containing partially digested food. Target organ is the small intestine where it stimulates the buffer secretion and increases blood flow through intestinal capillaries and relax his intestinal smooth muscle. Targets the pancreas where it increases secretions. Targets the stomach where is it inhibits acid secretion.

Mucosal barrier

Composed of 1) bicarbonate rich mucus 2) epithelial cells joined by tight junctions 3) stem cells replace dsmaged epithelial mucosal cells

First, presence of fatty, hyper tonic, acidic chyme in duodenum. Second, duodenal enteroendocrine cells secrete enterogastones (secretin, CCK) Third, this leads to contractile force of stomach declining and rate of stomach emptying declining.

Explain the sequence of hormonal factors inhibiting gastric emptying

First, presence of fatty, hyper tonic, acidic chyme in duodenum. Second, Chemo receptors and stretch receptors trigger enterogastric reflex. Simultaneously the short reflex via enteric neurons and long reflex via CNS centers (sympathetic activity increases, parasympathetic decreases) which leads to contractile force of stomach declining and rate of stomach emptying declining.

Explain the sequence of neural factors inhibiting gastric emptying

CKK

Hormone produced in the duodenum you closer. Stimulated for production by fatty kind. Targets the stomach where at in Hibbetts stomach secretory activity. Targets liver and pancreas where it potentiate secretaries actions on these organs. Targets the pancreas where it increases output of enzyme rich pancreatic juice. Gallbladder where it stimulates organ to contract and it spells stored file. Target hepato-pancreatic sphincter wear it relax The specter to allow entry of bile and pancreatica juice into the duodenum. Stop

Gastrin

It is produced by the G cells in the stomach mucosa. It is stimulated by food in the stomach and also by acetylcholine released by nerve fibers. It targets the parietal cells in his stomach where it increases HCl secretion and stimulates gastric emptying. It targets the small intestine where it stimulates contraction of the intestinal muscle. It targets the ileocecal valve where it relaxes the ileocecal valve. It targets large intestine where it stimulates mass movements.

Intestinal gastrin

Produced in the duodenal mucosa. Stimulus for production is acidic and partially digested food is in the duodenum. It target stomach where it stimulates gastric glands and a motility.

Motilin

Produced in the duodenal mucosa. Stimulus for production is fasting, and periodic release every one and a half to two hours by neural stimuli. It targets the proximal duodenum where it stimulates migrating motor complex.

Glucose dependent insulin a tropic peptide

Produced in the duodenum Macosa. Stimulated to be produced by fatty Keim. Targets the stomach where it inhibits HCl production. Targets the pancreas the beta cells, where it stimulates insulin release.

Histamine

Produced in the stomach mucosa. Stimulated for production buy food in the stomach. Targets the stomach where it activates parietal cells to release hydrochloric acid

Secretin

Site of production is the duodenal mucosa. Stimulus for production is acidic time also partially digested proteins and fats. It targets stomach weird inhibits gastric glands secretion and gastric motility. It targets the pancreas where increase output of pancreatic juice rich and bicarbonate ions and potentiate see CCK action. And it targets the liver where increase his bile output.

Somatostatin

Site of production is the stomach and you Xhosa and the duodenal mucosa. Stimulus for production is Food in stomach and stimulation by sympathetic nerve fibers. It targets the stomach where inhibits gastric secretion of all products. It targets the pancreas where inhibits secretion. The target small intestine where inhibits G.I. blood flow and thus inhibits intestinal absorption. Targets the gallbladder and liver where it inhibits contraction and Bile release.

Serotonin

Site of production is the stomach mucosa. Stimulus for production is food in his stomach. Target organ is the stomach where it causes contraction of stomach muscle.

Chief cells

They produce pep Synergen which is the in active form of pepsin, and they secrete lipases which are fat digesting enzyme's.

Parietal cells

secretes hydrochloric acid and intrinsic factor.