21 Flashcards
What is the peritoneum
A serous membrane
What does the partial layer line?
The body wall
What does the visceral layer line
The organs
What is between the parietal and visceral layer
Fluid filled spaces
Where is the retroperitoneal ?
- posterior to the peritonitium
What is a Mesentery
Double layer of visceral peritoneum that connects organ to body wall
(Holding it in place)
Omenta
Double layer of visceral peritoneum that connects an organ to another organ (one organ will always be the stomach)
Lesser omentum: connects liver to stomach
Greater omentum: connects stomach to the transverse colon (folds over small intestine like an ape Ron
The stomach is a _-shaped organ
J-shaped
Where is the stomach located?
At the base of the esophagus
Where does the esophagus pass through
The diaphragm
- esophageal hiatus
What is the esophagus passing throug diaphragm called
Esophageal hiatus
What prevents reflux
Lower esophageal sphincter
What does the Lower esophageal sphincter do?
Prevents reflux
4 main parts of the stomach
- cardia
- fundus
- body
- Phylorus (pyloric antrum)
Mucosa is modified for
Secretion
What allows for expansion ?
Temporary folds (rugae)
What does the extra muscular is layer (oblique) allow for?
Motility
What controls the passage into the duodenum
Phyloric sphincter
Omentum
a double
layer of peritoneum
that connects one
organ to another
Lesser omentum:
Stomach to liver
• Greater omentum:
Stomach to
transverse colon
The muscularis is modified for
Motility
3 layers of the muscularis
3 Layers:
• Oblique (inner)
• Circular (middle)
• Longitudinal (outer)
Modifications to the sub mucosa - RUGAE - what are they and what are they important for?
- rugae are temporary folds that allow for the expansion of the stomach (1.5L)
- core of submucosa
- important for storage
Modification to mucosa in stomach - what kind of epithelium? Glands?
• Simple columnar epithelium
• In-folding increases surface area for secretion – gastric glands
• Glands do not flatten
The stomach needs: ….. for digestion? For protection? For hormones?
• Acid and enzymes for digestion
• Mucous for protection
• Hormones for regulation
Gastric glands
What do mucous eptutheloial cells secrete?
Mucus for protection
What do parietal cells secrete
Acid and intrinsic factor
What do G cells secrete
Hormones (Gastrin)
What do chief cells secrete
Secrete pepsinogen (an inactive precursor of pepsin)
What do are chief cells? What are their features?
Chief Cells: Produce enzymes
• Abundant rough endoplasmic reticulum
• Apical zymogen granules (contain pepsinogen)
• Basal nucleus
What do parietal cells produce
Parietal Cells: Produce acid
• Pump ions (H+)
• Abundant mitochondria
• Central nucleus
• Folded structure to increase surface area
Regulation of stomach function - endocrine control
- Endocrine cells in mucosa
• Gastrin and Ghrelin secreted into the bloodstream
Regulation of stomach function - neural control
Neural control: • Enteric nervous system
(ENS) - local reflexes
(primary control) • CNS modulates ENS
function – long neural
reflexes
True or False?
• Parietal cells have large amounts of zymogen granules
• Rugae are folds of the mucosa, submuscosa and musclaris
• The innermost layer of the muscularis is oblique
• Gastric pits sit deep to the gastric glands
F
F
T
F
We need a controlled relase of digested material (chyme) into the small insteatine…. How do we do this?
Using pyloric sphincter
When acidic chyme enters the SI.. what is required by the small intestine…? What provides each requirement?
– Further digestion (enzymes)
– Protection from acidic chyme
• Mucous
• Neutralize acid
• Mucous provided by glands in the submucosa of the duodenum.
• Enzymes and bicarbonate provided by pancrea
Where is the pancreas located?
- retroperitoneal
- head is located in the C-shaped duodenum
- posterior to the stomach
The pancreas has a duct into the?
Lumen
The pancrease has both _______ and ______ functions
Has both endocrine and exocrine functions
Endocrine function of the pancrease
• Pancreatic islet alpha cells
secrete glucagon
• Pancreatic islet beta cells
secrete insulin
Exocrine function of the pancreas
• Acinar cells secrete digestive enzymes (via function into lumen)
• Duct cells secrete bicarbonate
Structure of Pancreatic Acinar Cells
Structure:
• Apical zymogen granules
• Basal nucleus
• Abundant rough ER
Function of Pancreatic Acinar Cells
Secrete enzymes
Where does the bile duct meet pancreatic duct ?
At the entercne of the hepatopancreatic ampulla
What projects into the duodenal lumen
The duodenal papilla
What controls the realise into the duodenal lumen
hepatopancreatic
sphincter
• What are the key structures of the stomach?
LES prevents reflux into esophagus, 4 regions- cardia, fundus, body and pylorus, pyloric sphincter controls entry into small intestine
• What structures of the stomach are needed
for storage and digestion?
Rugae allow expansion of stomach
Three layers of muscularis for motility
Gastric glands contain chief cells (pepsin) and parietal cells (HCl)
• What parts of the pancreas are important for
secretion?
Acinar cells secrete enzymes, duct cells secrete bicarbonate, secretions enter hepatopancreatic ampulla then into small intestine
