digestive system TEAS

Ingestion

Intake of food

Digestion

Definition: Breakdown of biomolecule polymers into building blocks.

Absorption

Breakdown of biomolecule polymers into building blocks.

Elimination

Removal of waste from the body.

Mechanical digestion

Physically breaking down food into smaller particles.

Chemical digestion

Enzymes break down nutrients into smaller molecules using saliva.

Saliva

Lubricates food; begins chemical digestion.

Dry mouth

Lack of saliva

Epiglottis

Flap covering trachea during swallowing to prevent food from entering lungs.

Peristalsis

Involuntary constriction and relaxation of digestive tract muscles to move food.

Hydrochloric acid (HCl)

Strong acid in the stomach that kills bacteria and activates pepsin

Pepsin

Chief digestive enzyme in the stomach that breaks proteins into polypeptides.

Chyme

Pulpy acidic fluid passing from the stomach to the small intestine.

Lower esophageal sphincter

Separates esophagus from stomach; prevents acid reflux.

Pyloric sphincter

Separates stomach from small intestine; prevents backflow

Duodenum

First and shortest part of the small intestine; chemical breakdown of fats, proteins, and carbohydrates.

Villi

Small hair-like projections in the small intestine that increase absorption surface area.

jejunum

Middle part of the small intestine; absorbs nutrients into the bloodstream.

Ileum

Final part of the small intestine; absorbs vitamin B12, bile salts, and fat-soluble vitamins (E, D, K).

Ascending colon

Absorbs water and salts from digested material.

Transverse colon

Transports digested material across the abdomen.

Descending colon

Moves solid waste to the rectum; stores feces until elimination.

Rectum

Final segment of large intestine; stores feces before expulsion.

Liver

Metabolizes carbohydrates and proteins; produces bile.

Gallbladder

Stores bile from the liver

Pancreas

Produces pancreatic juices to neutralize chyme.

Gastrin

Hormone that stimulates gastric glands to secrete pepsinogen and HCl.

Cholecystokinin (CCK)

Hormone that prompts the pancreas and gallbladder to release enzymes and bile.

Secretin

Hormone that regulates pH by inhibiting gastric acid secretion and stimulating bicarbonate production.

Insulin

Hormone that lowers blood glucose by storing glucose as oxygen

Glucagon

Hormone that raises blood glucose by stimulating liver to break down glycogen.

Bile

Substance the emulsifies fats, aiding digestion and absorption