Digestive system & metabolism

What is the primary function of the digestive system?

To break down food into nutrients the body can absorb and use

What are the main organs of the digestive system?

Mouth, esophagus, stomach, small intestine, large intestine, rectum, anus

What accessory organs aid digestion?

Salivary glands, liver, gallbladder, pancreas

What is peristalsis?

Wave-like muscle contractions that move food through the digestive tract

What is the role of saliva?

Contains enzymes (amylase) that begin starch digestion and lubricates food

What is the function of the stomach?

Stores food, mixes it with gastric juices, and begins protein digestion

What enzyme breaks down proteins in the stomach?

Pepsin

Where does most nutrient absorption occur?

Small intestine

What are villi and microvilli?

Finger-like projections in the small intestine that increase surface area for absorption

What is the role of bile?

Produced by the liver and stored in the gallbladder; emulsifies fats to aid digestion

What enzyme breaks down fats?

Lipase

What does the pancreas secrete to neutralize stomach acid?

Bicarbonate ions

What is the primary function of the large intestine?

Absorb water and electrolytes; form and store feces

What is metabolism?

The chemical processes that occur within the body to maintain life, including breaking down nutrients for energy

What is anabolism?

Building up of complex molecules from simpler ones (e.g., protein synthesis)

What is catabolism?

Breaking down of complex molecules into simpler ones, releasing energy

What is basal metabolic rate (BMR)?

The amount of energy expended at rest to maintain basic bodily functions

What is the function of the liver in metabolism?

Processes nutrients, detoxifies harmful substances, produces bile, stores glycogen

What hormone regulates blood sugar by lowering it?

Insulin

What hormone raises blood sugar levels?

Glucagon

What is the function of the gallbladder?

Stores and concentrates bile for fat digestion

What is chyme?

A semi-fluid mass of partially digested food expelled by the stomach into the small intestine

What is the role of the esophageal sphincter?

Prevents stomach acid from flowing back into the esophagus

What is the difference between mechanical and chemical digestion?

Mechanical digestion physically breaks down food; chemical digestion breaks down food molecules with enzymes

What is the function of the appendix?

Has a minor role in immunity; its function is not fully understood

What is the role of the enteric nervous system?

A system of nerves controlling the gastrointestinal tract independently of the CNS

What vitamins are produced by gut bacteria?

Vitamins K and some B vitamins

What is lactose intolerance?

The inability to digest lactose due to lack of the enzyme lactase