gastrointestinal tract Flashcards
what is the GI tract composed of? (7)
mouth, pharynx, esophagus, stomach, small intestine, large intestine, rectum
what does accessory digestive organs mean?
the organs that HELP the digestive organs do their job
what are the accessory digestive organs in the digestive system? (5)
teeth and tongue
salivary glands (amylase)
gallbladder- store bile (breaks fats) produced by liver
liver
pancreas
where does most absorption occur in the digestive system?
small intestine
what does bile do?
emulsifies fats into smaller molecules
what does the pharynx do?
stops food from entering respiratory system
what is the function of the GI tract?
to digest, absorb nutrients and provide protection.
what happens to the ph of your body when you vomit?
body becomes alkaline as you lose acid, need to go through homeostasis to restore
what’s the opposite of secretion?
absorption
what does active absorption require
ATP
what’s the difference between the GI tracy and the rental system?
GI system absorbs everything and doesn’t regulate concentration of each ion whereas the renal system maintains homeostasis of ions
what are 4 major activities of the GI TRACT?
- motility - moves (propels) ingested food from mouth to rectum
- secretion- aids in digestion and absorption process
- digestion- chemical and mechanical breakdown of food into absorbable units
- absorption- active or passive transfer of substances from lumen to the extracellular fluid
where do absorbed nutrients go for more processing?
liver takes In the absorbed nutrients after coming out of small intestine
what is chyme?
what the digested food in the stomach Is called after
what are the 2 patterns of gastrointestinal smooth muscle contractility?
- segmentation contractions
2.peristaltic contractions
what do peristaltic contractions do?
move food along gut in oral to anal direction
orchestrated waves of contraction and relaxation that move wave like along gut
mainly happens in oesophagus and small intestine
in peristaltic contractions what is the ball of broken food called
bolus
which is propulsive and non-propulsive contractions?
peristaltic contractions are propulsive (movement)
segmentation contractions are non-propulsive
what happens in segmentation contractions?
mixing of food and keeping it in contact with epithelium
where does segmentation contractions mainly occur?
small intestine
why does the food stay in contact with the epithelium?
they have small microvilli which increase surface area to aid absorption of nutrients
where are enzymes secreted from? (2)
endocrine glands (salivary glands and pancreas)
epithelial cells in mucosa
why does mucus line the stomach?
so acid doesn’t burn away lining of stomach
what’s digested in the mouth
mainly starch
what’s digested in the stomach
mainly proteins
what is digested in the small intestine? (3)
proteins, starch, fats
what is happens in the large intestine in terms of bacteria?
some fermentation of carbs and proteins by bacteria
what happens in the large intestine?
proteins stach and fats broken down into smaller molecules for absorption