Food is a nourishing substance necessary for energy, growth, and sustaining life, containing six essential nutrients: carbohydrates, lipids, proteins, vitamins, minerals, and water. The digestive process begins with ingestion in the mouth, where food is broken down by teeth and saliva, primarily produced by three major pairs of salivary glands. The digestive system includes the alimentary canal and various organs that process food and excrete waste.

2. Food
• Is a nourishing substance that we take into our
body through eating or drinking.
• Packed with nutrients that provide energy,
promote growth, and sustain life.
6 Types of Nutrients that our Body needs:
Carbohydrates Lipids Proteins Vitamins Minerals Water

4. Digestive tube or
Alimentary canal
where the food we
eat travels where it
gets digested
Different digestive
organs process the
food along the
gastrointestinal tract
(GI) and excrete the
waste materials
through the anus.
Metabolism
The process on how the cells use the
energy that they obtained from food during
digestion.

5. The first stage of digestion is called
ingestion. It happens as the food
enters the mouth.
It begins with mastication or chewing.
The teeth break, cut, and grind food
into smaller pieces, while the tongue
helps mix the saliva with the food.
INSERT PICTURE
(THE MOUTH)

6. SALIVA
3 PAIRS OF MAJOR SALIVARY GLANDS
a. Parotid glands- inside of the cheeks, below and in front of each
ear canal
b. Submandibular glands- beneath the lower jaw, under the floor of
the mouth, about 2 fingers above the laryngeal prominence, about
5 cm apart under the chin.
c. Sublingual glands- under the tongue
• Secreted by the salivary glands located
around the oral cavity
• It is a liquid that contains 99% water
• Contains the enzyme called ptyalin or
salivary amylase