Flashcards in GI module 3 Deck (107)
What is the total length of the small intestine?
Where does the small intestine begin and end?
begins at pyloric sphincter, and ends at ileocecal valve
What are the 3 regions of the SI and their respective lengths?
Duodenum (25-30cm) Jejunum (2.5m), and ileum (3.5m)
What region begins at the duodenal bulb and ends at the ligament of Trietz?
What structure allow bile and pancreatic enzyme secretions?
Hepatopancreatic ampula (sphincter of Oddi)
What structure is located in proximal duodenum and secretes "bicarbonate rich mucus to protect against acid chyme entering the duodenum and lubricate intestinal wall?
Describe the 2 major functions o the duodenum?
Digestion- stimulates release of enzymes from pancreas and gallbladder
Gastric feedback-provides feedback to regulate the rate of gastric emptying.
What is the initial signal for feedback pathways in the duodenum?
Acidic chyme entering the duodenum
What do the Long loop reflexes in the duodenum stimulate?
CNS increase sympathetic and decrease parasympathetic to stomach-
What do the short loop reflexes in the duodenum stimulate?
enteric neurons in stomach to decrease stomach motility
What hormones messengers work in the duodenum to inhibit motility/acid production?
Secretin, VIP, CCK
What is the major role of secretin in the duodenum?
Regulates the pH, inhibitory gastric activity and facilitates digestion
What stimulates the secretion of the hormone secretin in the duodenum?
Acidic (pH less than 4-5) chyme containing fats, partially digested protein, and hyper/hypotonic fluids
What are the target organs of the hormone secretin?
What is the driving force for Secretin?
What is the driving force for CCK?
What is the primary function of CCK?
Promotes bile/pancreatic enzyme release and inhibitory gastric activity
What is the stimulus for CCK?
Fatty chyme entering duodenum
What are the target tissues for CCK?
What is the action of CCK at the stomach?
Inhibitory gastric motility/secretions
What is the action of CCK at the Pancreas?
Stimulates release of pancreatic enzymes
What is the action of CCK at the Liver
Stimulates bile output (promotes fat digestion)
What is the action of CCK at the gallbladder?
Contraction to release stored bile
What is the action of Secretin at the stomach?
Inhibits gastric secretion and motility
What is the action of secretin at the pancreas?
stimulates pancreas to secrete bicarbonate solution (neutralizes)
What is the action of secretin at the liver?
Stimulates bile output (fat digestion)
What is the action of Brunner's glands of the duodenum?
Stimulates secretion of "alkaline rich mucus"
What is GIP said to be a relative of?
What is the stimulus for GIP?
Chyme entering the duodenum