"Digestion and Absorption of Food" PPT (first lesson)

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"Digestion and Absorption of Food" PPT (first lesson)

Part One: Situation Import

1. Why are people with chronic gastrointestinal diseases thinner?

2. Why do some people eat a lot but never gain weight?

nutrients in food

Water, inorganic salts, vitamins → direct absorption

Carbohydrates, proteins, fats → absorbed after digestion

Digestion: Converts complex macromolecules that are insoluble in water into simple small molecules that are soluble in water.

Food Digestion and Absorption PPT, Part 2 Content: Learning Objectives

1. Outline the components of the digestive system and describe the process of food digestion;

2. Identify the types of teeth and describe the structure of teeth;

3. Explain the causes of dental caries, the dangers of dental caries, and the functions and health care methods of teeth.

Digestion and absorption of food PPT, Part 3: Composition of the digestive system

The human digestive system consists of a digestive tract and digestive glands that secrete digestive juices.

Salivary glands secrete saliva, which moistens the mouth and facilitates swallowing and speaking. Human saliva contains amylase, which can initially break down starch in food.

The stomach is the most distended part of the digestive tract and is located in the upper abdomen.

The inner surface of the stomach has many folds, which contain many gastric glands that secrete gastric juice. Gastric juice has the functions of sterilization, digestion and protection of the stomach wall.

There is a well-developed smooth muscle layer in the stomach wall, which can continuously move to promote the mixing of food and gastric juice.

The liver is the largest digestive gland in the human body, and the bile secreted by the liver flows into the gallbladder for concentration and storage. Adults secrete about 1 liter of bile every day.

The pancreas secretes pancreatic juice. After eating, bile and pancreatic juice flow into the duodenum through the common bile duct and pancreatic duct to aid digestion.

Food digestion and absorption PPT, Part 4: Structure and function of teeth

Observation: Use a mirror to observe the teeth in your mouth. How many teeth do you have in total?

And clearly see the distribution positions of the incisors, canines, premolars, and molars.

The role of teeth: an important organ for people to eat and digest.

The total number of human teeth is 28 to 32.

(1)Classification of teeth

Teeth are the hardest organs in the human body and can be divided into incisors (incisors), canines (canines) and molars (premolars and molars).

Function: The incisors can bite and cut food, the canines are responsible for tearing food, and the molars are responsible for grinding food and finally crushing it.

A person has two sets of teeth in his life. One is the 20 deciduous teeth, which appear at half a year old and fall out between the ages of 7 and 12; the second are the 32 permanent teeth, which are replaced around the age of 6 and all but the last third molar have erupted by around the age of 12. The third molars usually erupt after the age of 20, and are also called wisdom teeth. There are also people who never give birth, so 28 to 32 is normal.

Causes of dental caries: Microorganisms decompose sugars in food and produce acidic substances. The acid corrodes tooth enamel and dentin, thus causing dental caries.

Harm: Increase the burden on digestive organs such as the stomach and intestines, affecting the digestion and absorption of food.

Food digestion and absorption PPT, Part 5: Summary of this lesson

1. Digestive system

Digestive tract: oral cavity, pharynx, esophagus, stomach, small intestine, large intestine and anus

Digestive glands: salivary glands, gastric glands, liver, pancreas and intestinal glands

2.Teeth

Types Incisors (cut teeth), canines (canines), and molars (molar teeth)

Composition: enamel, gums, dentin, pulp, nerves, blood vessels

Function: chewing, language and pronunciation, maintaining normal facial shape

Dental caries is caused by microorganisms and affects human digestion and absorption.

Food Digestion and Absorption PPT, Part 6 Content: Class Practice

1. The digestive system is composed of ________ and ________.

2. The digestive tract from top to bottom consists of ____, ____, ____, ____, ____, large intestine and anus.

3. Write the name of the relevant structure based on the diagram.

4. Which of the following is not a direct function of teeth ()

A． Cut off food b. Swallowing food

C. Grind food D. Digest food

5. When tooth decay occurs, it will hurt when exposed to hot or cold stimulation. This is because there are () in the dental pulp.

A. Pulp B. Blood vessels C. Nerve D. Dentin

Keywords: Zhejiang Education Edition ninth grade science PPT courseware free download, food digestion and absorption PPT download, .PPT format;

For more information about the "Digestion and Absorption of Food" PPT courseware, please click the "Digestion and Absorption of Food" ppt tab.

"Digestion and Absorption of Food" PPT courseware:

"Digestion and Absorption of Food" PPT Courseware Part One: Digestive System Composition of the Digestive System The human digestive system consists of a digestive tract and some digestive glands that secrete digestive juices. ... ... ... Food Digestion and Absorption PPT, Part 2...

"Digestion and Absorption of Food" PPT (Lesson 3):

"Digestion and Absorption of Food" PPT (Third Lesson) Part One Content: Learning Objectives 1. Describe the chemical nature and functions of enzymes; 2. Outline the characteristics of high efficiency and specificity of enzyme catalysis; 3. Distinguish between various An experiment to verify the properties of an enzyme. ... ... .....

"Digestion and Absorption of Food" PPT (second lesson):

"Digestion and Absorption of Food" PPT (Second Lesson) Part One: Reviewing the Past and Learning the New 1. What does the digestive system consist of? 2. What are the composition and types of teeth? 3. What are the causes of dental caries? What's the harm? Learning Objectives 1. Name protein,...

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Update Time: 2024-11-03

This template belongs to science courseware Zhejiang Education Edition Ninth Grade Science Volume 1 industry PPT template

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