SI and Pancreas (midterm) Flashcards
The ___________ is more dense CT than the areolar CT in the mucosa
submucosa
What cells are found in the intestinal glands?
1) absorptive cells
2) goblet cells
3) enteroendocrine cells
4) paneth cells
What is the function of absorptive cells inside of intestinal glands?
digest and absorb nutrients
What is the function of goblet cells?
test q
secretes mucus
What cells secrete hormones like secretin, CCK, and GIP?
enteroendocrine cells
What is the function of paneth cells?
test q
secretes lysozyme and is capable of phagocytosis to kill bacteria
Simple columnar cells are found in the mucosal layer of the SI and contains crypts of Lieberkuhn (deep to surface) which secretes ___________ and makes brush border enzymes
intestinal juice (note: this is slightly alkaline (7.6) whereas gastric juice is very acidic)
The submucosal layer of the SI has duodenal Brunner’s glands that secrete…
alkaline mucus to continue to raise pH of chyme
Intestinal juice provides a vehicle for absorption of substances from _______ as they come in contact with the villi. Some digestion will continue to occur in the lumen of the SI, especially until pH is neutralized
chyme
Brush border enzymes break down compounds on the surfaces of their microvilli. Peptidases like ______________________ attach remaining peptide bonds and nucleosideases and phosphatases continue to breakdown DNA and RNA
aminopeptidases or dipeptidases
Sucrose needs to be converted to what to be digested/absorbed?
glucose or fructose
Which hormone is secreted in the G cells of the antrum, duodenum, and jejunum, and stimulates gastric acid secretion and mucosal growth in the stomach?
test q
gastrin
Which hormone is secreted in the I cells of the SI and stimulates:
-pancreatic enzyme secretion
-pancreatic bicarbonate secretion
-gallbladder contraction
-growth of exocrine pancreas
(basically stimulates pancreas to release more exocrine cells)
and inhibits gastric emptying?
test q
CCK
Which hormone is secreted in the S cells of the SI and stimulates:
-pepsin secretion
-pancreatic bicarbonate secretion
-biliary bicarbonate secretion
-growth of exocrine pancreas
and inhibits gastric acid secretion?
test q
secretin
Which hormone is secreted in the K cells of the duodenum and jejunum and stimulates insulin release (carbs stimulate insulin release) while inhibiting gastric acid secretion?
test q
gastric inhibitory peptide (GIP)
What are the 3 parts of the pancreas?
head, body, and tail
The head of the pancreas is close to the curve in C-shaped ________
duodenum
The pancreas is connected to the duodenum via the main duct (duct of wirsung) and accessory duct (duct of santorini). The main duct joins the common bile duct from the liver and forms the ________________ duct. The hepatopancreatic sphincter (sphincter of oddi) on the hepatopancreatic ampulla (ampulla of vater) controls secretions (its close to the pyloric sphincter)
note: the location of pancreatic secretion release is relative to chyme released into duodenum
hepatopancreatic
The pancreatic acini are dark clusters that take up 99% of the gland and produce _____________________________. The islets of langerhans are 1% of the gland and are pale staining cells that produce many hormones
bicarbonate rich pancreatic juice
The islets of langerhans have alpha cells that produce what hormone? What is the function of this hormone?
glucagon
-raises the conc. of glucose in the bloodstream
-synthesis of glucagon is stimulated during fasting and is decreased during fed state
The islets of langerhans have beta cells that produce what hormones? What is the function of these hormones?
insulin
-promotes the absorption of glucose from the bloodstream
-synthesis of insulin is stimulated by IV glucose or feeding and is decreased by fasting
-insulin targets the liver, skeletal muscle and adipose tissue to store excess glucose
amylin
-slows gastric emptying and promotes satiety (feeling of fullness)
What cells are most common in the islets of langerhans?
beta cells are 70% of the cells there
The islets of langerhans have epsilon cells that produce what hormone? What is the function of this hormone?
the hunger hormone
-secreted when stomach is empty, and stops secretions once the stomach starts stretching from food
-secreted from adipocytes and works in the hypothalamus
Pancreatic juice is generated in response to ________ from the duodenum and jejunum
secretin
What does pancreatic juice contain and what does it do?
water, enzymes, and sodium bicarbonate
it fixes the pH of chyme exiting the stomach
What are the 5 types of enzymes in pancreatic juice?
1) pancreatic amylase
2) pancreatic lipase
3) trypsinogen
4) serine proteases
5) ribonuclease and deoxyribonuclease