1What are the 5 cells found in gastric glands?
1. Mucus neck cells
2. chief cells (zymogenic cells)
3. parietal cells
4. enteroendocrine (G - Cells)
5. Stem cells
2What is the function of the mucous neck cells?
Secrete acidic mucus
3What is another name for chief cells and what is their function ?
Zymogenic cells
Function = secrete pepsinogen, gastric lipase, and rennin (infants)
4What are the hormones gastric lipase and rennin?
Gatsric lipase = help to digest milk fat
Rennin - found infants to curdle milk to thicken for slower digestion
5What is the function of parietal cells?
Secrete HCL which actives the pepsiongen to break down proteins
6What is another name for G cells and their functions?
Enteroendocrine cells
Function = releases hormones into lamina propria, Stimulated by CN (x) vagus
7What is Gastrin?
Hormone secreted by g cells that regulates stomach secretion and motility
8What hormones does the CN (X) stim and what’s the name?
vagus
Stim -
1. pepsinogen
2. HCL
3. Mucos
4. Stomach gastrin
9What happens during the Cephalic phase?
= reflex phase
befor food reaches stomach it prepares via stim from sight, smell, though of food to cerebral cortex or hypothalamus
10What happens during the gastric phase?
Stim by peptides or alkaline pH
also stim by gastrin from protein absorbed in blood
>increase acidic food inhibits response
11What are the 2 components of the intestinal phase?
Inhibitory & excitatory
12What happens during the excitatory intestinal phase?
On switch for intestinal secretions
starts when food enters duodenum
13What happens during the inhibitory or enterogastric reflex phase?
1. Inhibits vagus nerve nuclei in medulla
2. inhibits local reflexes
3. activates sympathetic fibers to close pyloric sphincter
14What hormones are released during the entergastric reflexes?
1. secretin = decrease gastric secretion
2. cholecystokinin (CCK) = inhibits gastric emptying via pancreas & gallbladder
Production increased with fatty meal
15What si the importance of the pyloric sphincter?
Chyme pushed against it only liquid through very small hole (acting as a filter)
16What are some things that affect gastric emptying? how long?
Takes 4-6 hours to enter duodenum
increased carbs empty faster
next proteins
fat takes longest due to its stim of CCK
17What is the enterogastric reflex?
reflex insures stomach doesn’t release more chyme than duodenum can handle
Stim such as distinction of duodenum inhibits gastric emptying
This then triggers entergastric reflex which inhibits parasympathetic and stims cholecystokinin prod
18What is the role of trypsinogen?
digest protein
activates procarboxypeptidase and chymotrypsinogen
19What is the role of pancreatic amylase?
Carbphydrate digesting enzyme
its produced active but requires bile for optimum performance
20What is the role of pancreatic lipase?
fat digestion
its produced active but requires bile for optimum performance
21What is the role of the ribonuclease and deoxyribonuclease?
nucleic acid digesting
22What are the 6 enzymes produced by the pancreas?
Trypsinogen
Pancreatic amylase
Pancreatic Lipase
Ribonicleaus
Deoxiribonucleaus
Sodium bicarbonate
23What is the role of sodium bicarbonate>
raises the pH of chyme inhibiting gastric juices
24What are the 4 ways to control secretions?
CCK
Secretin
Parasympathetic
Sympathetic
25Whoes does CCK effect secretions?
Stim of acini cells to relaxes enzymes in presence of protein or fat
26how does secretin effect secretion?
Stim of duct cells to release HCO3 in presence of HCL
27How does sympathetic NS effect secretions?
Regulates blood flow to pancreas
28How does parasympathetic NS effect secretions?
Stim secretion from both cell types