GI system Flashcards
what digestive enzyme is present in the mouth and begins the breakdown of starch
salvilary amylase
describe the voluntary stage of deglutition
food is shaped into a bolus
tongue is raised against the hard palate to crease a pressure gradient that forces the bolus into the pharynx and beyond
describe the involuntary stage of deglutition
swallowing reflex
nasopharynx is closed by the soft palate
food is prevented from entering the airway by the epiglottis
upper esophageal sphincter relaxes so bolus can enter esophagus
breathing is inhibited until food is in the esophagus
what causes GERD
lower esophageal sphincter is incompetent and allows the flow of gastric juices and contents back into the esophagus
“heart burn”
when is food stuff considered “chyme” and not a “bolus”
when it enters the stomach to begin chemical breakdown of proteins
what is the function of mucous neck cells
secrete acid mucus in the stomach
what is the function of parietal cells
secrete HCl and intrinsic factor into the stomach
what is the function of chief cells
produce pepsinogen in the stomach to breakdown proteins
what is the pH of the stomach
2
describe gastritis
inflammation of the gastric mucosa
ulcers can form due to damage of the gastric mucosa allowing Helicobacter pylori to reach the gastric lining
what are peyer’s patches and where can they be found
contain B and T cells and are found in the submucosal lining of the small intestine
describe digestion in the small intestine
carbohydrates and proteins are only partially digested
no fat digestion has taken place
where does nutrient absorption take place
small intestine
what is the largest gland in the body
liver
describe cholesterol gallstones
most common
main risk factor is excessive excretion of cholesterol
common in obese patients
