Anatomy Unit 4 - Absorption and Excretion

The functions of the digestive system

Digestion, absorption and excretion

Digestion

Breaking down food into smaller molecules to be absorbed

Absorption

Transporting nutrients from the small intestine into the bloodstream

Excretion

Elimination of undigested waste products as feces

The Two Parts of the Digestive System

The alimentary canal and the accessory organs

The Alimentary Canal

The digestive tract where nutrients are absorbed

The Accessory Organs

Create and excrete fluids essential for disgestion

The Two Types of Digestion

Mechanical and chemical digestion

Mechanical Digestion

The physical breakdown of food through chewing and contractions of smooth muscle

Mastication

The first step of the digestion process when food is chewed and crushed in the mouth

Peristalsis

Contraction of smooth muscle that occur as food goes through the digestive tract

Chemical Digestion

The chemical breakdown of food using enzymes and acid

What are carbohydrates broken down into?

Glucose

How is excess glucose stored?

As glycogen

What are fats broken down into?

Fatty acids or cholesterols

What are excess fatty acids stored as?

Fat

What are proteins broken down into?

Amino acids

What are amino acids used for?

To build or repair cells (specifically bone, muscle, and nerve tissue)

What is the role of enzymes in digestion?

To break down food into smaller molecules

What does the mouth do in mechanical digestion?

Breaks food down and moistens it

What does the mouth do in chemical digestion?

Saliva has enzymes in it that breaks down carbohydrates, starting the chemical digestion process

Bolus

Partially digested food going from the esophagus to the stomach

Pharynx

A passageway in the back of the nasal and oral cavities that leads to the esophagus

Epiglottis

A flap of cartilage protecting the larynx and trachea by closing to prevent food or water from entering the lungs

Two substances in the stomach that helps digest food