GI Secretions 1 and 2 - combo 1/17 Flashcards
Recheck hormones (first half)
3 glands that contribute to Saliva
• Parotid Glands - serious fluid (contains amylase) • Submaxillary glands - mixed serous/mucous fluid • Sublingual glands - mucous fluids
Secretin promotes ____, inhibits ______
promotes — pancreatic bicarb secretions and an alkaline pH in the duodenum (high pH) inhibits — gastric acid secretion (acid is low pH)
CCK decreases ______, increases secretion of _______ and ______
decreases gastric emptying, and increases pancreatic enzyme secretion, and bile secretion (gall bladder contractions)
VIP
VasoACTIVE intestinal Polypep – “active” – it increases intestinal motility.
______ is the only hormone that promotes GASTRIC functions (acid secretion and motility)
Gastrin — promotes gastric acid secretion and motility
Alkaline Tide
HCO3- / Cl - Exchanger
apical surface of the parietal cells have ____
proton pumps
as salivary flow increases, the osmolality ____ due to a _____
increases, decrease in the reabsorption of electrolytes
CCK
CCK is released from the duodenum as soon as chyme enters into it (due to vagal stimulation) - causes the release of digestive enzymes and bile from pancreas and gallbladder
cephalic phase
- sensory activation (sight, smell), anticipatory response - Glossopharyngeal and facial nerves – increase saliva production - Vagus (Ach) – stimulates parietal cells to secrete HCl to prepare stomach for food (before it gets there)
Changes in GIT due to fever
- increasing GI contractions, pushing chyme out of tract faster, and decrease absorption - metabolic rate goes up
Co-lipase
makes the lipids accessible to the pancreatic lipase
Colon Secretions
reabsorb all of the remaining Na+ and Cl-
enterokinase
trypsinogen to trypsin
gastric phase
stretch and gastrin release
GIP: GIP stands for 2 things
a. Gastric inhibitory polypeptide: inhibit gastric acid secretion. b. Glucose dependent insulinotropic polypeptide.
H. pylori
natural resistance to our gastric acid protective mucus barrier
how does chloride come into the lumen?
HCO3- is exchanged for Cl-
how is H+ made?
the metabolism of CO2, the bicarbonate is secreted into the blood resulting in an alkaline tide
if you reduce blood flow to a gland, you reduce _____
the ability of the gland to secrete
if you stimulate the ____, you get a tremendous increase in salivary flow. If you stimulate the ____, you don’t get much of an increase in flow
parasympathetics inc salivary flow sympathetic stimulation would not increase flow
in addition to GI peptides, ____ is produced in adipose tissues and is a counterpart of ghrelin. It decreases appetite by suppressing ____
leptin, NPY
in the fasting state, ____ is secreted into the blood from _____ cells in the stomach
ghrelin, oxnytic (parietal)
in the ____ of the hypothalamus, ghrelin stimulates ____, an orexigenic peptide which stimulates a sense of ___
arcuate nucleus, NPY, hunger
intestinal phase
vagal reflex and then inhibitory local ENS reflex
Jejunum and Ileum
bulk reabsorption of all of those electrolytes we’ve been secreting
NO – nitric oxide
–ultimate smooth muscle relaxer, so it reduces motility and relaxes sphincters.
NPY hormone
stimulates HUNGER.
parietal cells
canaliculi
Peptic ulcer
inflammation causes mucosal damage
Peptide YY and GLP-1
- promote satiety as chyme moves through intestines - surpasses both gastric and pancreatic secretion (by suppressing Ach and stimulating somatostatin) - released from ilium??
you can tell from its name that this hormone also promotes intestinal motility.
Motilin!
saliva is always ____ to plasma
hypotonic
satiety is a result of many different GI peptides, including ____. They suppress ____, decreasing appetite
peptide YY and GLP-1 (glucagon-like peptide) hypothalamic NPY
the amount of acid that is made is determined by ____
the number of pumps inserted into the membrane
the concentration of H+ in the lumen is ____x higher than in the cell
10^6
the concentration of K+ in saliva is about ___ whereas the concentration in the plasma is about ___
20 mEq/L, 4
the parotid glands secrete:
serous fluid w/ amylase
the sublingual glands secrete:
mucous fluid
the submaxillary glands secrete:
mixed serous/mucous fluid
This is the only hormone that causes gallbladder contraction.
CKK: “cholecyst” = gallbladder, “kinin” = move. – gall bladder –> bile secretion, important for lipid digestion. Also important for lipid digestion– Pancreatic lipase! CKK increases secretion of Pancreatic enzymes. ** CKK decreases gastric emptying.**
Vagus efferents, Gastrin, and Histamine
stimulating gastric acid secretion
What are the 7 functions of saliva?
“COLD TAP” coagulation factors oral hygiene lubrication digestion taste antimicrobial protection
what are the gastric secretions?
HIPGLaHMS _HCl- chemical digestion (parietal) _Intrinsic factor (IF)- protect B12 (parietal) _Pepsinogen- digests proteins (chief) _Gastrin- HCl secretagogue (G-cells in antrum) _Lipase- lipid digestion (chief) _Histamine - increase HCl _Mucus- protection _SS - suppress HCl
what are the three paired saliva glands?
parotid glands submaxillary glands sublingual glands
What controls flow of Saliva?
PNS glossopharyngeal and facial nerves
What controls salivary flow? If you severed these nerves, what happens?
- PNS controls flow of saliva through glossopharyngeal and facial nerves - without these nerves salivary glands would atrophy
what enzymes are found in saliva and what do they do?
α-amylase: for starch digestion lingual lipase: lipid digestion (more important in babies) R-binders (proteins): bind and protect B12 from proteases in the stomach
what happens to metabolic rate in fever?
it goes up
What inhibits all secretion, does not affect motility– the “inhibitory hormone”?
Somatostatin: [somato-stat stops secretions, and is static]
– inhibits all secretions (acid, pepsinogen, HCO3-, pancreatic enzymes, insulin, glucagon).
– It does not affect motility.
What is the “anticipatory reaction”?
increased gastric acid secretion
what things decrease salivary flow?
“SAD - ADHD’S” sympathetics (NE) aging Dehydration ADH, Aldo (hormones) Drugs Sleep
what things increase salivary flow?
parasympathetics (Ach) CNS (cephalic phase) nausea esophageal distension (bolus!) chewy, flavorful foods dry, acidic, alkaline foods meats, sweets, bitter foods
α-Amylase
digest starch molecules
4 Hormones that affect the stomach:
” Get Caught Seretin Gastrin”
GIP, CKK, Secretin, Gastrin
The inhibitory hormone
Somatostatin
3 Hormones that affect intestinal motility:
NO, VIP, and Motilin
Stomach distension increases motility of the stomach via _____ and intestine via_____
increases motility of the stomach (via Gastrin) and intestine (via VIP).
* When the stomach’s full, you want the food to move along to the next part of the GIT.
when the stomach is too acidic, you’ll want to bring the pH back to normal by decreasing acid secretion, by …..
- DEC Gastrin = dec acid secretion
- INC secretin + Somatostatin = dec acid secretion
when there’s glucose in your GIT, you’ll want to get ready for it by having insulin available, which is done via ____
GIP
fatty acids increase the secretion of
CCK, GIP, Secretin
** fatty acids are digested by pancreatic lipases which require an alkaline pH to function**
Both amino acids and fatty acids increase the secretion of ____ and _____.
CCK and GIP.
Amino acids also increase secretion of these 3 things:
“CGG” = CCK, GIP, Gastrin
[think: proteins are digested by pepsin, acid makes pepsinogen into pepsin, need acid!]
Vagal stimulation increases ___ and ___, decreases ____________.
- INC – Gastrin and VIP
- dec – Somatostatin
- Chief of Pepsi-Cola
- PARI
Chief cells of stomach produce Pepsin
Parietal cells Produce Acid & Release Intrinsic factor
4 mneumonics
- Lesser OMentum holds Liver and stOMach
- Mesentery holds the sMall intestine
- mesoCOLON attaches COLON to posterior abdominal wall.
- e. coLI is found in the Large Intestine
