Flashcards in Digestive System Deck (128)
In L, how much gastric juices is secreted per day?
What regulates secretion?
long and short reflexes and hormones
What are the 3 phases of the gastric secretion?
cephalic, gastric, and intestinal
When does the cephalic phase occur?
Before food enters the stomach
What triggers the cephalic phase?
triggered by smell, taste, sight or thought
Which nerve stimulates the enteric neurons?
vagus causing secretion
When does the gastric phase occur?
once food reaches the stomach
How much gastric juice is the in the stomach?
What provoked the gastric phase?
distension of short and long reflexes, peptides and rising pH stimulate gastrin
When does the intestinal phase occur?
Once food enters the duodenum
How is the intestinal phase inhibited?
enterogastric reflex and release of intestinal hormones
What provokes the intestinal phase?
distension of duodenum, presence of fats, and acidic chyme
What is inhibited to promote gastric secretion?
Enteric neurons and vagus nerves
Which 2 hormones are secreted by intestinal hormones?
cholecystokinin and secretin
In gastric contractile activity what happen to chyme?
3 ml into dudoenum and 27mL forced back into stomach
Where does the small intestine begin or end?
begins at pyloric sphincter and ends at ileocecal valve
From proximal to distal what are the parts of the small intestine?
duodenum, jejunum, and ileum
Where are the bile duct and main pancreatic duct located?
Bile duct: from liver
Main pancreatic duct: pancreas unite in wall of duodenum
What controls entry of bile and pancreatic juice?
What are the 3 structural modifications in the small intestine?
circular folds, villi, microvilli
What is the function of the 3 structural modifications in the small intestine?
increase surface area for absorption
What forms the circular folds? Purpose
Formed by mucosa and submucosa.
Forces chyme ti slowly spiral through lumen
Fingerlike projections of mucosa and contain capillary beds and lacteals
Form brush border and brush border enzymes
What do the pits of the villi lead?
lymphoid nodules in mucosa of ilium
submucosa of duodenum, secrete alkaline in mucus