L.2 Flashcards
The Gastrointestinal motility and secretion controlled by a great number of GIT hormones which ………….. secreted by……
polypeptides , special mucosal cells
The special mucosal cells in the GIT are called :
enteroendocrine or APUD احفظوها على انو شخص اسمو (عبود)
Hormonal regulation for GIT function They are classified into:
• Gastrin family
• Secretin family
• Other hormones
Gastrin family:
• Gastrin
• cholecystokinin (CCK)
Secretin family :
• Secretin
• gastric inhibitory peptide (GIP)
• vasoactive intestinal peptide (VIP).
The other hormones that regulation of GIT function :
• Motilin
• somatostatin
• gastrin releasing peptide (GRP or bombesin)
What is the 3 forms of Gastrin that classified according to the number of A.A?
- G 14
- G17 (little gastrin )
- G 34 (big gastrin )
The Gastrin  It is secreted by……. In…………
• G cells
• in the antral mucosa of the stomach
The section of Gastrin is stimulated by Luminal factors which is :
• Gastric distension decreased gastric acidity (انتفاخ المعدة يعني ““اذا اكلت كتير وشبعت “” حتتقلل حموضة المعدة ) + ( Gastrin يقل يطلع ال acidityلمن ال )
• Presence of “protein digestive” products in the stomach
دي العوامل الي تخلي ال Gastrin يطلع
The action of Gastrin :
من حيث ال stimulation
• Stimulation of gastric motility and secretion especially HCl معلومة للفهم —> (HCL اذا زاد , Gastrin hormone will stop)
• Stimulation of small intestinal motility
• Helps normal growth of GIT mucosa
The action of Gastrin :
• “Contraction of lower esophageal sphincter” preventing reflux of gastric contents into
the esophagus بالفهم حتتبسط
• Relaxation of ileocecal sphincter | للتوضيح ( ileocecal open and the food pass through it to small intestine then to large intestine )
How many amino acid is Cholecystokinin containing
33 amino acids
Cholecystokinin It is secreted by……. in the……
• I cells
• duodenal and jejunal mucosa
The section of Cholecystokinin is stimulated by :
• Protein digestive products
• Long chain fatty acids
Thr Action of Cholecystokinin according the stimulation:
• Stimulation of enzymatic pancreatic secretion
(small in volume, poor in HCO3- and “rich”in enzymes).
• Stimulation of intestinal motility.
The Action of Cholecystokinin :
• Contraction of pyloric sphincter
• Contraction of gall bladder
• relaxation of the sphincter of Oddi which causes evacuation of the gall bladder
• Inhibition of gastric emptying and secretion
The Cholecystokinin Augmenting the action of :
secretin
How many amino acid is Secretin containing ?
22 amino acids
Secretin It is secreted by……. in the……
• S cells
• duodenal and jejunal mucosa.
The section of Secretin is stimulated by :
• Arrival of acid chyme with PH < 4.5 to the duodenum
•Protein digestive and Fatty acids
The Secretin Augmenting the action of :
Cholecystokinin (CCK)
Gastric inhibitory peptide (GIP) It is secreted by……. in the……
• K cells
• mucosa of the duodenum and jejunum
Gastric inhibitory peptide (GIP) It’s secreted in response to presence of :
• Fat
• Carbohydrates
The action of Gastric inhibitory peptide (GIP) :
• It decreases the gastric emptying into the duodenum.
when the upper small intestine is over supplied with food products
يعني ال GIP يقول للstomach كفااية اكل
Vasoactive intestinal peptide (VIP) It is secreted from……
upper part of small intestine
The action of Vasoactive intestinal peptide (VIP) :
• vasodilation of intestinal blood vessels
• Regulation of gastrointestinal motility
•Stimulation of pancreatic NaHco3 secretion.
• Inhibition of gastric secretion
Motilin It is secreted by…….. scattered in……
• special cells (mo cell)
• small intestine
The action of Motilin :
• Stimulation of antral and duodenal motility
• Contraction of lower esophageal sphincter.
Somatostatin It’s Secreted from……. and……..
• stomach
• upper part of the small intestine
The action of Somatostatin :
Inhibition of secretion of gastrin and secretin
The Action of Secretin according the stimulation:
• Stimulation of aqueous pancreatic secretion
(large in volume, rich in HCO3- and poor in enzymes)
• Contraction of pyloric sphincter.
• Inhibition of gastric motility and secretion.
“Secretin loves bicarbonate and hates acidity”
