Lecture 11: GI Secretory Functions, Digestion, & Absorption Flashcards
The second stage of salivary secretion of ions occurs in the _____.
Salivary ducts
Where does the first stage of salivary secretion of ions occur?
Acini
What is the final ionic concentration of saliva?
Na+ & Cl-: 15 mEq/L
K+: 30 mEq/L
Bicarbonate: 50-70 mEq/L
During maximal secretion of ions in saliva, the increase can be _____.
20-fold
Chief cells secrete _____ in response to Ach from _____ nerve or gastric enteric nervous plexus
Pepsinogen
Vagus
What do parietal cells secrete?
HCl
What sort of nervous stimulation causes gastric secretions?
Parasympathetic
What is gastrin released in response to the presence of?
Protein in the plylorus
Gastrin causes enterochromaffin-like cells to release _____ which causes the secretion of _____.
Histamine
HCl
What causes cephalic phase stimulation?
Vagus nerve
What causes gastric phase secretion?
Local nervous secretory reflexes
Vagal reflexes
Gastrin-histamine stimulation
What causes intestinal phase secretion?
Nervous & hormonal mechanisms
What are the digestive enzymes for proteins?
Trypsin, chymotrypsin, & carboxypolypeptidase
How is trypsin kept from destroying pancreatic tissues?
Glandular cells secrete a trypsin inhibitor
What is the digestive enzyme for carbs?
Amylase
What are the digestive enzymes for fat?
Pancreatic lipase, cholesterol esterase, & phospholipase
What is released via stimulation of food in the upper intestine and increases secretion of pancreatic enzymes?
CCK
What is released via stimulation by presence of acidic foods in upper intestine and releases large amounts of sodium bicarbonate?
Secretin
Which of the following cause CCK release?
Fats
Amino acids
Carbs
Fats and amino acids
What stimulates the release of bile from the gall bladder?
Presence of fatty food
What are causes of gallstones?
Too much absorption of water, bile, or cholesterol or inflammation of epithelium
Glucose absorption in the small intestine utilizes a _____ mechanism.
Na+ active co-transport
Absorption of peptides/amino acids in the small intestine utilizes a _____ mechanism.
Na+ active co-transport mechanism
Absorption of fats in the small intestine utilizes a _____ mechanism.
Micelles & chylomicrons
What gets absorbed in the large intestine?
Na+ & Cl-
Water
Bicarbonate
