DAT Digestive System Flashcards
Initial digestion site
mouth
food mixed wit saliva
bolus
Area where food & air passages cross
Pharynx (Throat)
blocks trachea so only liquid & solids enter
eliglottis
Connects the mouth to the stomach
esophagus
Bolus travels by…
by peristalsis via smooth muscle & salivary lubrication
Food enters the stomach from the esophagus through the…
lower
esophageal/cardiac sphincter
what is In gastric juice
(digestive enzymes & HCl)
does absorption occur in stomach
no, none
Responsible for storage, mixing, physical & chemical breakdown food
stomach
(creamy mass of digested food)
chyme
Secrete mucus
mucus cells
Lubricates & protects the stomach’s
epithelial lining
mucus cells
Secrete pepsinogen, which is activated by
low pH in stomach
chief cells
Converts to pepsin
chief cells
(digests proteins)
pepsin
Secrete HCl
parietal cells
Secrete gastrin,
gastrin
stimulates parietal
cells to secrete stomach acid
gastrin
Food enters the small intestine from the
stomach through the
pyloric sphincter
Most digestion & absorption occurs here
small intestine
The walls of the small intestine have
projections called
villi
that increase
surface area, allowing for greater
absorption
villi
Each villi has
microvilli
3 Segments of the Small Intestine:
duodenum, jejunum, illeum
Continues breakdown of starches and proteins & remaining food types
duodenum
(majority of digestion occurs here)
duodenum
Majority absorption of nutrients occurs here.
jejunum
Absorption continues; contains Peyer’s patches (lymphoid tissue)
illeum
Food enters the large intestine from the small intestine via the
ileocecal valve
4 segments of ileocecal valve
Ascending, transverse, descending, and sigmoid
large intestine terminates at…
rectom
Major functions include… large intestine
both water & electrolyte absorption
Symbiotic bacteria in large intestine aid in digestion and provide…
vitamin k and b12
Produces bile,
liver
contains no digestive
enzymes but emulsifies fats
bile
contains sodium bicarbonate
to help neutralize stomach acid
bile
Cystic duct + hepatic duct à
common bile duct
Common bile duct + pancreatic duct ->
secretes
into the duodenum
Secretes bicarbonate and digestive enzymes to the duodenum
pancreas
Trypsin/chymotrypsin
digest protein
(digest lipids)
lipase
(digest carbohydrates)
amylyse
(digests nucleic acids)
nucleases
Digestive Enzymes initially exist as
as zymogens (inactive).
how do zymogens become active
cleaved in the small intestine to their active form
Digestive Enzyme Flow:
Produced in pancreas à flow from pancreatic duct into duodenum à
neutralizes acidic chyme from stomach & allows for digestion to occur
