exam 2 class 17 did not finish slide deck Flashcards
chyme entering the small intestine has undergone relatively?
little chemical digestion, controlled flow through pyrrolic sphincter
Intestinal contents are slowly propelled forward by?
segmental and peristaltic contractions
Parasympathetic innervation and the GI hormones gastrin and CCK
promote? what inhibits it?
intestinal motility
sympathetic innervation- part of your brain that is not active
has fingerlike villi and deep crypts
surface of lumen
most absorption
villi
fluid hormone secretion and cell renewal from stem cells
crypts
Surface of the intestinal epithelium is called the?
brush border
Most nutrients absorbed move into capillaries in the
villi for distribution through the?
circulatory system
fats pass into?
lacteals of the lymphatic system
transport nutrients and ions
enterocytes
transport most absorbed nutrients
capillaries
secrete mucus
goblet cells
transport most fat to the lymph
lacteals
divide to replace damaged cells
stem cells
secrete ions and water
crypt cells
secrete hormones
endocrine cells
where does venous blood from the GI tract go?
hepatic portal system
specialized region of
circulation has two sets of
capillary beds:
-one that picks up absorbed nutrients at the intestine
-another that delivers the nutrients directly to the liver
hepatocytes contain enzymes called?
cytochrome P450
metabolize drugs and xenobiotics and clear them from the bloodstream before they reach systemic
circulation
Hepatocytes
5.5 liters of food, fluid, and secretions enter small intestine each day, +
~3.5 liters of hepatic, pancreatic, and intestinal secretions are added
there, =?
9 liters into lumen
integrated function
- digestive enzymes
- bile
- biocarbonate
- mucus
-NaCl
intestinal epithelium and exocrine pancreas. Intestinal brush
border enzymes are anchored to luminal cell membranes. Stimulation of vagus nerve enhances enzyme secretion
Digestive enzymes
made in liver and released from gall bladder is a nonenzymatic solution that
facilitates digestion of fats
Bile:
neutralizes highly acidic chyme that enters from stomach. Most__________ comes from pancreas and is released in response to neural stimuli and secretin
Bicarbonate
from intestinal goblet cells protects epithelium and lubricates the gut’s contents.
Mucus:
isotonic solution mixes with mucus to help lubricant contents of the gut
NaCl
Crypt cells in small intestine and colon secrete?
isotonic NaCl
Pancreas contains 2 types of secretory epithelium:
endocrine and exocrine
Endocrine secretions: islets
hormones insulin and glucagon
Exocrine portion secrete?
digestive enzymes and a watery solution of sodium bicarbonate
converts inactive trypsinogen to active trypsin
Brush border
enteropeptidase
