final test Flashcards
where does digestion begin
digestion begins in the mouth; both chemically and physically
what two structures are joined by the cardiac sphinctor?
esophagus and stomach
what causes heartburn
failure of the cardiac sphincter
which of the following occurs in the stomach
secretion of gastric juice
which of the following chemically reacts with pepsinogen to create pepsin in the stomach
hydrochloric acid
what do parietal cells produce
hydrochloric acid
what do the submandibular and sublingual glands do?
releases substances in your mouth underneath tongue
what is a saliva a mixture of
saliva is a mixture of mucus and serous fluids
what do serous fluids contain
salivary amylase
what does saliva do
moistens and binds food together into bolus
what is bolus
a ball of food and saliva mixed together
what does the mouth coordinate
ingestion, digestion and initial propulsion
what is ingestion
chewing mechanism, chemically w/ amylase
what is ingestion
chewing mechanism, chemically w/ amylase
does food absorption take place in the mouth
no food absorption takes place, but drugs and chemicals can pass through the oral mucosa
what is deglutition
swallowing
what does deglutition initate
propulsion
what is involved in swallowing
tongue, soft palate, pharynx, and esophagus
what are the two major stages of swallowing
buccal phase and pharyngeal esophageal phase
what are the differences in the buccal phase and pharyngeal esophageal phase
the buccal phase is voluntary and the pharyngeal esophageal phase is involuntary
what is the buccal phase
bolus is forced into the pharynx by tongue
what is the pharyngeal esophageal phase
tongue blocks off mouth, soft palate closes nasal passages, larynx rises to be shut off
what is another word for pharynx
throat
what does the esophagus do
squeezes food along the stomach
what does not happen in the esophagus
no digestion (chemical or mechanical) occurs, food just passes thru
what are the actions of the muscles in the esophagus
involuntary and cause peristalsis
what does the stomach do?
stores food and breaks it down with acid and enzymes
what works together to make gastric acid?
chief and parietal cells
what makes pepsin?
pepsinogen and parietal cells
what does pepsin do
chemically breaks down proteins
where do carbs get broken down chemically
the mouth
where do proteins get broken down chemically
stomach
what does the pyloric spinchter
prevents substances from stomach to leak
what does the stomach do when its empty
collapses on itself and forms folds called rugae
what is churning
when the muscularis extrena works with the third oblique layer of smooth muscle
what is acid chyme
mixture of gastric acid and food
what do enteroendocrine cells produce
gastrin
what is gastrin
a hormone released that stimulates secretion of gastric acid
what can bacterial infections cause
ulcers
what are esophageal ulcers called
heartburn
what happens from stomach to small intestine
propulsion goes from stomach to small intestine
what does the enterogastric reflex do
slows down gastric activity, tightens pyloric sphincter, chyme fills duodenum
what does the small intestine do
major organ of chemical digestion and nutrient absorption
what is the longest section of the alimentary tube
small intenstine
what re the three major structures of the small intestine
villi, mircovilli, circular folds
what is the goal of villi
increase surface area for nutrient absorption
what does the acid chyme from stomach do
mixes with bile and pancreatic enzymes
what does the acid chyme do
raises ph of chyme from stomach
what does pancreatic juice contain
enzyme rich solutions
what are the enzymes rom pancreatic juices
pancreatic amylase, trypsin, chymotryspin, carboxypedtidase, lipids, nucleases
what does pancreatic amylase break down
carbs
what do carboxypedtidase, trypsin, chymotrypsin break down
proteins
what does lipase break down
lipids
what does nuclease break down
nucleic acids
what is the livers sole digestive function
bile production
where does bile enter
into s.i, and can be stored in gallbladder
how does bile get stored in the gallbladder
cystic duct
what is the action of bile referred to as
emulsification
what does bile do
mechanical digestion of fats, and serves a role in fat soluble vitamin absorption
what are the major functions of the large intestine
water reabsorption and elimination of indigestible food
where do good bacteria reside
they reside in the large intenstine and gut
what do these good bacteria do
metabolize remaining nutrients, produce gas, help synthesize vitamins
