Physiology Flashcards
What is the function of substance p?
Activation of smooth muscles in the intestine either directly or through activating cholinergic neurons (Ach)
What is the function of vasoactive intestinal peptide VIP?
Relaxation of smooth muscle in GIS (sympathetic)
What is the function of Bombesin or GRP ?
Increase gastric secretion
What are the neurotransmitters that induce contractions of the smooth muscle walls in the GIS?
Ach
Enkephaline
Substance P
Which hormone is responsible for inhibiting gastric emptying?
Cholecystokinin cck
What are the functions of gastrin?
Increase gastric acid secretion
Stimulates growth of gastric mucosa
What stimulates the release of gastrin?
Distention of stomach, vagal stimulation(Ach)—>gastrin-releasing peptide (GRP)—> stimulates G cells—> releases gastrin—> stimulates parietal cells—> secretes HCl acid secretion
Where and by what cells is Gastrin secreted?
Secteted by G cells in the antrum of stomach
What is the function of CCK or cholecystokinin?
-Promotes Fat digestion and absorption by increasing the release of pancreatic enzymes.
-Increases Bicarbonate HCO3-
-inhibits gastric emptying
-Induces contractions of gallbladder
How many amino acids is in Gastrin?
17
How many amino acids is in cholecystokinin?
33
Where and by which cells is CCK secreted?
Secreted by I cells in the duodenal and jejunum mucosa
Which hormones inhibit gastric emptying?
Secretin
Cholecystokinin (CCK)
Glucose-dependent insulinotropic peptide (GIP)
Which gastric factors promote gastric emptying?
Gastrin (hormone)
Increased food volume in the stomach
What stimulates the release of gastrin?
Distention of stomach
Eating a meal
Products of proteins
Vagal stimulation
Gastrin releasing peptide (GRP)
Which hormone promotes gallbladder emptying?
Cholecystokinin CCK
Which hormone is released in response to overeating (fats and proteins) to suppress appetite?
Cholecystokinin cck
Where and by what cells is the secretin released?
secreted by S cells in the mucosa of duodenum.
What are the functions of secretin?
-Acts to promote pancreatic secretion of bicarbonate that neutralizes acid in
small intestine.
-Mild effect on motility of GIT.
……… digests carbohydrates?
Pancreatic amylase
……… digest protein
Pancreatic protease
……. Digests proteins and fats
Cholecystokinin
………….. digest ingested lipids to fatty acids, monoglycerides, and cholesterol, all of which can be absorbed.
Pancreatic lipases
……….. slows the delivery of chyme (partially digested food) from the stomach to the small intestine, ensuring adequate time for the subsequent digestive and absorptive steps.
Cck cholecystokinin
……….. also inhibits the effects of gastrin on the parietal cells (H+ secretion and growth).
Secretin (&somatostatin)
…….. is secreted by K cells of the duodenal and jejunal mucosa.
Glucose-dependent insulinotropic peptide GIP
Which gastrointestinal hormone is secreted in response to all three types of nutrients: glucose, amino acids, and fatty acids?
Glucose-Dependent Insulinotropic Peptide (GIP)
What are the functions of Glucose-dependent insulinotropic peptide (gastric inhibitory peptide [GIP])?
-Mild effect in decreasing motor activity of the stomach—>slows emptying of gastric contents into the duodenum when it’s overloaded.
-Stimulates insulin secretion.
Which gastric hormone is secreted by the stomach and upper duodenum during fasting ?
Motilin
………….is released from intestinal cells in response to a decrease in blood glucose concentration.
It then directs the liver to increase glycogenolysis and gluconeogenesis.
Enteroglucagon
It then directs the liver to increase glycogenolysis and gluconeogenesis.
Enteroglucagon
