Digestion System Flashcards
(19 cards)
What is the path of food through the digestive tract?
Mouth → Pharynx → Esophagus → Stomach → Small Intestine (duodenum → jejunum → ileum) → Large Intestine → Rectum → Anus.
What happens in the mouth during digestion?
Mechanical digestion by teeth; chemical digestion begins with salivary amylase converting starch into maltose.
What is the role of the pharynx and epiglottis in swallowing?
The pharynx directs food into the esophagus. The epiglottis covers the trachea to prevent food from entering the airway during swallowing.
What is peristalsis?
Wavelike muscle contractions that move food through the digestive tract, especially in the esophagus, stomach, and intestines.
What is the function of the esophagus?
A muscular tube that uses peristalsis to transport food from the pharynx to the stomach.
What happens in the stomach during digestion?
Churns food, secretes HCl and mucus, converts pepsinogen to pepsin, which begins protein digestion.
What is chyme?
A semi-liquid mixture of partially digested food and gastric juices that exits the stomach into the small intestine.
What are the three sections of the small intestine and their functions?
Duodenum (chemical digestion), jejunum, and ileum (absorption of nutrients via villi and microvilli).
What is the function of the villi and microvilli?
Increase surface area for nutrient absorption. Capillaries absorb glucose and amino acids; lacteals absorb fats.
What happens in the large intestine?
Absorbs water, minerals, and some vitamins. Hosts E. coli bacteria that produce vitamins. Forms and stores feces.
What are the six major functions of the liver?
1) Makes bile 2) Destroys old RBCs 3) Detoxifies substances 4) Regulates blood glucose 5) Makes blood proteins 6) Converts ammonia to urea.
What is the function of the gallbladder?
Stores and releases bile into the duodenum to emulsify fats.
What is the function of the pancreas in digestion?
Secretes enzymes (amylase, trypsin, lipase, nuclease) and sodium bicarbonate to neutralize stomach acid.
What is the role of insulin and glucagon?
Insulin lowers blood glucose by promoting storage; glucagon raises blood glucose by promoting glycogen breakdown.
What digestive enzymes are involved in breaking down carbohydrates?
Amylase (starch to maltose), maltase (maltose to glucose).
What digestive enzymes break down proteins?
Pepsin and trypsin (proteins to peptides), peptidase (peptides to amino acids).
What enzyme breaks down fats and what helps it work?
Lipase (fats to glycerol and fatty acids); bile emulsifies fats to aid enzyme access.
What is the role of nucleases?
Breaks down DNA and RNA into nucleotides.
What are CCK and secretin and what do they do?
Hormones released by the duodenum. CCK stimulates bile and enzyme release; secretin stimulates pancreatic bicarbonate release.
