digestive Flashcards
(27 cards)
What are the 4 main stages of digestion?
Ingestion → Digestion → Absorption → Elimination
What is mechanical digestion?
Physical breakdown of food (e.g., chewing, churning in the stomach).
What is chemical digestion?
Enzymatic breakdown of food into small molecules.
What does the mouth do in digestion
Begins mechanical digestion with chewing and chemical digestion with salivary amylase.
What does the stomach do?
Churns food and uses gastric juice (HCl and pepsin) to begin protein digestion.
What is chyme?
The semi-liquid mixture of partially digested food and digestive juices in the stomach.
What does the small intestine do?
Site of most digestion and nutrient absorption; uses enzymes from pancreas and bile from liver.
What does the large intestine do?
Absorbs water and forms feces.
What does the liver do?
Produces bile, processes nutrients, detoxifies blood.
What does the gallbladder do?
Stores and releases bile into the small intestine.
what does the pancreas do in digestion?
Produces enzymes (amylase, lipase, proteases) and bicarbonate to neutralize stomach acid.
What does amylase do?
Breaks down starch into sugars (salivary and pancreatic).
What does lipase do?
Breaks down fats into fatty acids and glycerol (pancreatic).
What does pepsin do?
Begins protein digestion in the stomach.
What does bile do?
Emulsifies fats, making them easier to digest by lipase.
What type of digestive system do humans have?
Monogastric (single-chambered stomach).
What is the main site of nutrient absorption in humans?
Small intestine.
What enzyme begins starch digestion in the mouth?
Salivary amylase.
What enzyme begins protein digestion in the stomach?
Pepsin.
What enzymes are secreted by the pancreas?
Amylase (starch), lipase (fats), trypsin (proteins).
What type of digestive system do ruminants have?
Polygastric (four-chambered stomach).
What are the four compartments of the ruminant stomach?
Rumen, reticulum, omasum, abomasum.
What happens in the rumen?
Microbial fermentation of cellulose; produces volatile fatty acids (VFAs).
What is the function of the reticulum?
Traps heavy/dense objects; aids in regurgitation (cud chewing).
