Stomach and Pancreas Flashcards
Name the 4 major regions of the stomach and describe them
- The cardia= surrounds the the superior opening of the stomach
- The fundus=rounded portion superior and to the left of the cardia
- The body= large central portion inferior to the fundus
- The pyloric= last part of the stomach that leads to the duodenum
Name the 3 portions of the pyloric and describe their fxn
- Pyloric antrum= connects to the body of the stomach
- Pyloric canal= narrowing area that connects the pyloric antrum to the pylorus
- Pylorus= area that connects to the pyloric sphincter
Where are the three specialized cells that secrete products into the stomach lumen
gastric pits
What do chief cells secrete, what stimulates them, and what do they do
Secrete: pepsinogen
Stimulated by: luminal proteins (protein in the stomach)
Fxn: breaks down proteins, only proteolytic enzyme in the stomach
What do parietal cells secrete and what stimulates them
Secrete: HCL, Bicarb, Intrinsic factor
Stimulated by: luminal proteins (protein in the stomach) and Gastrin releasing peptide
What is gastrin releasing peptide
a neurotransmitter released by the vagus nerve endings
What do G cells produce, where are they found, and what do their products do
Produce= gastrin
Found only in the pyloric antrum
Fxn’s: Gastric is both a paracrine and endocrine hormone
- simulates parietal cells to release HCL
- stimulates histamine to be released from enterochromaffin like cells which activates parietal cells
- stimulates epithelial cell repair/proliferation
What do D cells produce, and what do their products do
Produce= somatostatin GHIH
Fxn’s: inhibits Gastrin release from G cells
What do enterochromaffin like cells produce, and what do their products do
Produce: Histamine
Fxns: activates parietal cells to produce more HCL
What drugs block the drugs block histamine
Tidines… ranitidine, cimetidine
What is the basal pH of the stomach and what is the pH in the stomach when food is present
Basal=4-6
pH with food= ~2
At what pH is pepsinogen rapidly activated
<3
What do goblet cells produce and why is it important
Produces= mucus
Fxns= provides constant layer of mucus that protects stomach cells from the very acidic luminal content
Where are the gastric “pacemaker” cells located and what do they do
Located= greater curvature of the stomach
Fxn= begins propulsion wave every 15-20 seconds that moves the gastric content back and forth to help breakdown food particles to small enough to fit through the pylorus
True or false gastric lipase plays a major role in digestion of TAGs
False, only released in small amounts and usually only plays a role in pancreatic insufficiency
What are clusters of glandular cells that produce digestive enzymes/fluids in the pancreas called
Acini
What is another name for the pancreatic duct
Wirsung duct
What is another name for the accessory duct of the pancreas
Duct of Santorini
What is formed by the merger of the common bile duct and the pancreatic duct
the ampulla of vater aka hepatopancreatic ampulla
What surrounds and controls the flow of fluid out of the ampulla of Vater (aka hepatopancreatic ampulla)
Sphincter of Oddi
What is the fxn of pancreatic juice
- Buffers acidic chyme
- Stops action of pepsin (by bring up the pH)
- Contains many digestive enzymes
What can cause acute pancreatitis
- EtOH
- Cystic fibrosis
- Hypercalcemia
- Hyperlipidemia
- Drugs
- Autoimmune dz’s
What are the 2 signs associated w/ acute pancreatitis and describe them
Cullen’s sign= Blood around the umbilicus flowing from the ligement of tres
Gray-turners sign=blood pooling in the retroperitoneal space
Where is gastric inhibitory polypeptide (glucose dependent insulinotropic polypeptide) released and what effect does it have
Released in the duodenum
in inhibits the gastric muscle decreasing peristalsis and slows gastric emptying
What is the enterogastric reflex
receptors in the duodenum are stimulated in the presence of chyme that inhibits gastric peristalsis
What is the gastroileal reflex
sensory and motor activity of the stomach send signals to the distal ileum early in the meal causing acceleration of movement through the ileocecal sphincter
What is the enterogastric reflex
signals from the small and large intestine distention inhibit stomach motility and secretion to allow for more time to move contents forward
What is the gastrocolic reflex
signals from excessive stomach activity (late meal) causes movement of feces in the colon to move forward into the rectum
