Ch. 24-25: Digestion and Nutrition

What is chyme?

The mixture of food and digestive juices created in the stomach through mechanical churning and chemical digestion.

What is the primary role of the small intestine?

It is the main site for chemical digestion and nutrient absorption.

How are nutrients transported after absorption in the small intestine?

Glucose, amino acids, and vitamins enter blood capillaries, while fatty acids and glycerol enter lacteals; all are transported to the liver via the hepatic portal vein.

What is the difference between plaque and tartar?

Plaque is a sticky film of bacteria on teeth, while tartar (calculus) is hardened plaque that irritates gums.

What are the four main stages of the digestive process?

Ingestion, digestion, absorption, and elimination.

Where does the majority of chemical digestion occur?

In the duodenum of the small intestine.

What is the function of bile in digestion?

It breaks down fats into small droplets to facilitate digestion.

What are the primary sites of nutrient absorption in the small intestine?

The jejunum and ileum.

What is the primary function of the large intestine (colon)?

It absorbs remaining water and electrolytes and compacts waste into feces.

What is the difference between dental plaque and tartar?

Plaque is a sticky film of bacteria on teeth; tartar is hardened plaque that irritates gums.

What are the primary functions of the soft palate and epiglottis during the pharyngeal phase of swallowing?

The soft palate closes the nasal cavity, and the epiglottis covers the trachea to prevent choking.

What is the role of the lower esophageal sphincter during the esophageal phase?

It relaxes to allow the bolus to enter the stomach.

Define nutrition.

The process of obtaining and using food for energy, growth, and body maintenance.

What are the primary functions of lipids in the body?

Long-term energy storage, insulation, and forming cell membranes.

What is the difference between monosaccharides, disaccharides, and polysaccharides?

Monosaccharides are simple sugars (e.g., glucose), disaccharides are two-sugar units (e.g., sucrose), and polysaccharides are complex carbohydrates (e.g., starch).

Where is excess glucose stored in the body, and in what form?

It is stored as glycogen in the liver and skeletal muscles.

What is the difference between glycogenesis and glycogenolysis?

Glycogenesis is the conversion of glucose into glycogen for storage; glycogenolysis is the breakdown of glycogen back into glucose for energy.

Distinguish between catabolism and anabolism.

Catabolism breaks down molecules to release energy, while anabolism uses energy to build molecules.