Lecture 21 Flashcards
Role of the lower esophageal sphincter?
Prevent reflux
What is the gross structure of thew stomach?
cardia
Fundus
Body
pylorus
What is the lesser Omentum?
Connects stomach to liver
What is the greater Omentum?
Connects stomach to transverse colon
How is the muscularis modified to carry out specific functions?
Modified for motility.
Consists of Oblique (inner layer), Circular (middle layer) and Longitudinal (outer layer)
What are Rugae?
Temporary fold on the internal surface of the stomach that allow for the expansion of the stomach. Important function for storage
(Folded core of submucosa with overlying mucosa)
Where are gastric glands located?
Mucosa of the gut tube
What do gastric glands secrete?
Mucous (protection)
Acid and Intrinsic Factor
Hormones (gastrin)
Pepsinogen
What cells do gastric glands contain?
Parietal
G
Chief
What do chief cells produce?
enzymes (pepsinogen)n - in the stomach
what do parietal cells produce?
Acid (HCL) - in the stomach
Location of chief cells
Throughout the fundus and corpus of the stomach
Function of chief cells ?
synthesis and release of the proenzyme pepsinogen, which subsequently, in an acid environment, is converted to the acid protease pepsin.
What is the function of parietal cells?
Parietal cells are responsible for gastric acid secretion, which aids in the digestion of food, absorption of minerals, and control of harmful bacteria.
Location of parietal cells?
fundus and body of stomach
Features of parietal cells?
Pum pions(H+)
Abundant mitochondria
Central nucleus
Folded structure to increase surface area
features of Chief cells?
Abundant rough endoplasmic reticulum
Apical zymogen granules (contain enzymes)
Basal nucleus
How is stomach function regulated?
Endocrine control - endocrine cells in mucosa secrete gastrin and ghrelin into the bloodstream.
Neural Control - enteric nervous system ( ENS - local reflexes/primary control)
CNS modulates ENS function
What is the role of the pyloric sphincter?
Controlled release of chyme into small intestine
Location of the pancreas?
• Head in C-shaped duodenum • Tail to spleen
• Posterior to the stomach
• Duct into duodenal lumen
RETROPERITINEAL
Role of the hepatopancreatic sphincter?
Controls release of bile and pancreatic juices from ampulla into second part of duodenum
Endocrine function?
- Pancreatic islet alpha cells secrete glucagon
* Pancreatic islet beta cells secrete insulin
Exocrine function?
- Acinar cells secrete digestive enzymes
* Duct cells secrete bicarbonate
Structure of pancreatic Acinar cells?
- Apical zymogen granules
- Basal nucleus
- Abundant rough ER
Function of Acinar cells?
secrete enzymes
