Biology 30.3 The Digestive System

What occurs during the Digestion?

" During digestion, food travels through the mouth, esophagus, stomach, and small intestine. Mechanical digestion and chemical digestion are the two processes by which food is reduced to molecules that can be absorbed"

How are nutrients absorbed and wastes eliminated?

"Most nutrients from food are absorbed through the walls of the small intestine. The large intestine absorbs water and several vitamins and prepares waste for elimination from the body.

What are the functions of the Digestive system?

"The digestive system converts food into small molecules that can be used by the cells of the body. Food is processed by the digestive system in four phases—ingestion, digestion, absorption, and elimination"

Large intestine

"The large intestine is actually much shorter than the small intestine. The large intestine gets its name due to its diameter, which is much greater than the small intestine's diameter

Peristalsis

Contractions of smooth muscles that provides the force that moves food through the esophagus towards the stomach.

Small intestine

Digestive organ in which most chemical digestion and absorption of food takes place

Amylase

Enzyme in saliva that breaks the chemical bonds in starches.

Pepsin

Enzymes that breaks down proteins into smaller polypeptide fragments.

Villus

Fingerlike projection in the small intestine that AIDS.

Stomach

Large muscular sac that continues the mechanical and chemical digestion of food.

Chyme

Mixture of enzymes and partially digested food.

Mechanical digestion

Physical breakdown of large pieces of food into smaller pieces.

Chemical digestion

Process by which enzymes break down food into smaller molecules that the body can use.

Esophagus

Tube connecting the mouth to the stomach.