Structure/Function/Control Flashcards
5 Functions
Digestion Motility Secretion absorption Excretion
Mechanisms of control in GI
Neural: ANS + Enteric nervous system
Endocrine: Hormones affecting distal organs
Paracrine: Histamine altering local function
Parasympathetic response
SLUD6 Salivation Lacrimation Urination DFefacation Digestions DEC HR DEC airway diameter DEC pupil Dilation erection
Enteric Nervous system segments and function
Myesteric Plexus: gut motility
Submucosal plexus: Intestinal absorption + secretion
Gastrin
- Stimulates gastric acid secretions in antrum
- Stimulated by peptides, distension, + stimulation
Diseases associated w/ Gastrin
- Zollinger-Ellison Sundrome
- PUD
CCK
- Stimulates Gallbladder + Pancreas
- stimulated by peptides + FAs
Secretin
- Stimulated by Acid
- Stimulates Pancreas, Liver,
- inhibits gastric acid secretions + gastrin
GIP
- Stimulates Insulin release
- inhibits gastric acid secretion
- stimulated by glucose, amino acids, + FAs
Pancreatic polypeptide
- Inhibits pancreas
- stimulated by orotein, fat, + glucose
GLP-1
- Where: Ilium/Colon
- Stimulates insulin
- Stimulated by glucose + fat
Somatostatin
- Inhibits other peptide hormones
- stimulated by acid, inhibited by vagus
Histamine + GI
- Stimulates acid secretions
- stimulated by gastrin + other unknowns
VIP
- relax sphincters; stimulate intestinal + pancreatic secretions
- stimulated by enteric nervous system
Bombesin
- stimulates gastrin release
- by ENS
Enkephalins
- Stimulate smooth muscle contractions; inhibit secretions
Xerostomia
- Atrophy of salivary glands
- Sjogren’s, radiation, + medication
- S/S: dental caries, halitosis, difficulty swallowing
- Tx: Pilocarpine
D Cells
Somatostain
Cephalic phase
- Vagus -> Parietal acid secretion, ECL histamine release, + GRP stimulates G Cells
Gastric Phase
- Gastric acid secretion via distention -> Vasovagal reflex
Intestinal phase
- Gastrin released by G Cells in SI in response to AA n chyme
Which two compounds are implicated int he vasovagal response in the stomach?
VIP + NO
NSAID Mechanism
inhbition of prostaglandins which normally produce protective mucus and HCO3- formation
PPI SE
Most Common: nausea, abdominal pain, constipation, + diahhrea
Parietal Cell Hyperplasia -> FGPs + acid rebound with discontinue of PPIs