GI Secretion Flashcards
Single cell mucous glands example:
Goblet cell
What type of glands are in the stomach and the intestines?
tubular glands
What are the intestinal glands called?
Lieberkuhn
In the duodenum, you would find ____________ glands
Brunner’s
Which type of secretion has the lowest ph?
gastric
The highest in volume secretion from the digestive tract is ?
Small intestine secretion
What is the most potent stimulus for secretion?
Food (mechanical, tactile, distention, chemical irritation)
What are the hormones that can stimulate secretion in the GIT?
gastrin
GIP
GLP-1
What prevents damage to the gut mucosa?
Mucus coat
List the 3 salivary glands
- parotid
- mandibular
- sublingual
What is the only salivary gland that is serous only?
parotid
The salivary glands are innervated by what division of the nervous system?
Parasympathetic ganglia
Saliva is isotonic or hypotonic once it is in the 2nd secretory step?
Hypotonic
Which salivary enzyme breaks down starch into maltose?
Salivary amylase
T/F you can find salivary amylase in all species
False: Not found in cattle, dogs, cats, horses
Which salivary enzyme breaks dow lipids?
Salivary lipase
What is the function of saliva?
Lubricate food and act as solvent
Is saliva acidic or basic?
Basic (pH 7.7-8.5)
What glands prevent mucosal excoriation along the esophageal lining?
Esophageal Submucosal gland
What is the first part of the stomach called, near the esophageal entrance?
Cardia
What are the surface mucous cells known as?
Foveolar epithelium
Which gastric glands are oxyntic glands?
fundic glands
The 4 types of secretory cells in gastric glands are:
- neck
- chief
- parietal
- enteroendocrine
Which gastric gland cells secrete mucus?
Neck cells
Which gastric gland cells secrete pepsinogen?
Chief
HCl is secreted by ________ cells in gastric glands
Parietal
D cells secrete _____________
Somatostatin
Which enteroendocrine cells secrete histamine?
ECL (enterochromaffin-like)
What is secreted to aid in Vit B12 absorption from gastric epithelial cells?
Intrinsic factor
Pepsinogen is cleaved by ____________ to produce pepsins
HCl
HCl is secreted especifically by the secretory network of _______________ of parietal cells
Canaliculi
What structure is unique to parietal cells that can transport protons against a concentration gradient?
Proton pump / H K Atpase
Which substances stimulate fusion of organelles and the proton pumps and thus HCl secretion ?
- histamine
- acetylcholine
- gastrin
Gastrin is produced by _____________ in response to AA in stomach lumen
G-cells
ACH is released when the vagus nerve acts on _______ receptors on parietal, ECL, and G cells
M
What inhibits the secretion of HCl?
Somatostatin
Aluminum hydroxide and magnesium hydroxide are ?
Antacids
A proton pump inhibitor example:
Prilosec
The cephalic phase of gastric secretion starts via which nerve?
Vagus nerve
Which division of the nervous system stimulate pepsin and acid production?
Parasympathetic
In which gastric secretion phase does gastrin and histamine get stimulated?
Gastric phase
What is the last phase of Gastric secretion?
Intestinal phase
What reflex inhibits secretion in the intestinal phase?
Reverse enterogastric reflex (myenteric nervous system)
The Reverse enterogastric reflex is initiated by?
Food in upper intestine
What hormones are inhibiting factors for gastric intestinal phase?
- GIP (gastric inhibitory peptide / glucose-dep insulinotropic peptide)
- GLP-1 (glucagon like peptide-I
- Somatostatin
What is secreted into the intestinal lumen and is then reabsorbed?
Water
Crypt cells actively secrete ___________, which in turn leads to more water secretion
Electrolytes
Crypt cells contain the chloride channel also known as________________, which secrete water
Cystic fibrosis transmembrane conductance regulator (CFTR)
GIp and GLP-1 inhibit gastric secretion in the intestinal phase, but stimulate secretion of what?
insulin from pancreas
Insulin secretion is induced by which hormones?
Incretins - GLP + GIP
The large intestine secretes mucus via ______________
goblet cells
The intestinal glands in the LI are also called:
crypts of Lieberkuhn
Where does reabsorption of water and electrolytes occur?
Large Intestine
Which vitamins are produced in the Large intestine by bacteria?
B and K
Dietary fiber in chyme are fermented via anerobic or aerobic respiration?
Anaerobic
What is produces in fermentation?
Short-chain fatty acids (acetic and butyric acid)
What enzyme is present in herbivores to produce cellulose?
Cellulase
In hind gut fermenters, microbial digestion is important due to the source of ?
VFAs
