Lesson on Human Body – The Mouth IV for Primary 4

Hello, young learners! Welcome back to Primary 4 Basic Science Technology. In our previous lesson, we learned about Human Body – The Mouth III. Today, we’re going to learn about the work of the salivary gland and saliva.

Objectives

By the end of this lesson, you should be able to:

• Understand the functions of saliva and the salivary gland.
• Appreciate the importance of saliva in the digestive process.
• Discuss the social aspects of saliva in food tasting and digestion.

The Work of the Salivary Gland and Saliva

What is Saliva?

Saliva is a clear, watery fluid produced by the salivary glands in your mouth. It plays a vital role in digestion and oral health.

Functions of Saliva in Feeding:

There are many important functions of saliva, and they are:

• Saliva starts the process of digestion by breaking down starches into simpler sugars.
• It lubricates the mouth, making swallowing easier.
• Saliva helps in taste perception by dissolving food particles.
• It contains enzymes that aid in the digestion of food.
• Saliva acts as a cleanser for the mouth, washing away food particles and bacteria.
• It helps in the formation of the food bolus for easier swallowing.
• Saliva plays a role in oral health by neutralizing acids and aiding in tooth remineralization.

Importance of saliva in the digestive process:

The main functions of saliva in the digestive process are:

1. Starts Digestion: Saliva contains an enzyme called amylase which begins the process of breaking down starches into simpler sugars right in the mouth.
2. Lubrication for Swallowing: It moistens food, making it easier to chew and swallow. Without saliva, swallowing dry or coarse food would be difficult.
3. Taste Enhancement: Saliva helps in dissolving food particles, which enhances the ability to taste. It’s essential for appreciating the flavors of various foods.
4. Oral Health: Saliva helps to cleanse the mouth by washing away food particles and bacteria, reducing the risk of tooth decay and gum disease. It also neutralizes acids that can erode tooth enamel.

Evaluation

Now that you’ve learned about the work of the salivary gland and saliva, let’s see if you can answer these questions:

1. What is the primary enzyme found in saliva and what is its function?
2. How does saliva contribute to oral hygiene?
3. Describe how saliva assists in the digestion of food.
4. What are some ways we can keep our mouths healthy?
5. Why is it important to brush our teeth after meals?

Conclusions or Summary

We learned that saliva is a vital fluid produced by the salivary glands in our mouths. It plays a crucial role in digestion, starting the breakdown of food and making swallowing easier. Saliva also helps us taste our food and keeps our mouths clean and healthy. Don’t forget to check the comments section if you have any questions, and use the navigation to move to the next lesson. See you in the next lesson!