Chapter 14-digestive system Flashcards
what are the accessory organs in the digestive system
salivary glands, pancreas, liver, gallbladder
what does salivary amylase do
converts starch to maltose
what do mucous cells do
secrete mucus to protect the stomach lining from the acidic stomach
where are mucus cells located
in gastric pits
where are chief cells located
in gastric pits
what do chief cells do
synthesize pepsinogen which is converted to pepsin upon contact with stomach acid, breaks down proteins
what do parietal cells do
synthesize and release HCL which alters stomach pH, kills bacteria, and produces intrinsic factor
what are the 3 sections of the small intestine
duodenum, jejunum, ileum
what are the enzymes that aid in digestion in the small intestine
lipases, aminopeptidases, disaccharides
what produces bile
the liver
what stores bile
the gallbladder
where are parietal cells located
in gastric pits
what are the nondigestive functions of the liver
storage of glycogen, conversion of ammonia to urea, protein synthesis, cholesterol metabolism
what is the first pass effect
blood from small intestine is sent to the liver for detoxification before entrance into general circulation
what does the pancreas release
amylase, lipase, and trypsinogen
what activates trypsinogen
enterokinase
where is enterokinase produced
the small intestine
where is gastrin produced
in G cells in the duodenum
what does gastrin do
- stimulates histamine and pepsinogen secretion
- increases gastric blood flow
- stimulates parietal cells to secrete HCl
what secretes intrinsic factor
parietal cells in the stomach
what does intrinsic factor do
facilitates absorption of vitamin B12 across intestinal lining
what secretes secretin
S cells of upper intestine
what does secretin do
stimulates the secretion of bicarbonate containing substances from the pancreas and inhibits gastric emptying and gastric acid production
what does ghrelin do
increased ghrelin circulation causes increased appetite and feeding behavior
where is ghrelin produced
the brain and gut
where is leptin synthesized
in adipose tissue
what does leptin do
- serves as an antagonist to ghrelin
- acts on the brain to reduce hunger and provide a satiated state
