"Digestion and Absorption of Food" PPT (Second Lesson)

Description

"Digestion and Absorption of Food" PPT (Second Lesson)

Part One: Review the past and learn 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 target

1. Explain the digestion process of protein, starch and lipid;

2. Name the absorption parts and processes of various substances;

3. Outline the structural characteristics that are compatible with the functions of the small intestine.

Digestion and absorption of food PPT, Part 2: Digestion and absorption of food

(1) Digestion of food:

1. Digestion: The process by which the human body breaks down food (macromolecule compounds) into small molecule compounds that can be used by the body.

2. Type of digestion:

(1) Physical digestion-----completed in the digestive tract

(2) Chemical digestion-----completed under the action of digestive juice

3. Absorption: The process in which digested nutrients and some nutrients that do not need to be digested enter the circulatory system through the wall of the digestive tract is called absorption.

A classmate finished his physical education class late and was pressed for time. He went to the dining hall to wolf down his food and felt a little uncomfortable in his stomach after the meal. What was the reason?

Do equal amounts of the same type of food with different shapes and sizes affect the digestion speed?

The smaller the shape and volume of food, the faster it is digested.

Thinking: Which of the seven major nutrients can be absorbed directly without digestion? Which ones need to be digested?

(2) Absorption of nutrients:

1. Absorbable in the digestive tract

Site: stomach, small intestine, large intestine.

2. Nutrients absorbed by each part:

3. Where do nutrients go after being absorbed?

Enters the circulatory system and is transported throughout the body by the blood.

What structural characteristics does the small intestinal wall have that are compatible with its digestive and absorptive functions?

1. There are many types of digestive juices in the small intestine (pancreatic juice, intestinal juice, bile)

2. The wrinkled walls and small intestinal villi on the surface of the small intestine greatly increase the surface area of ​​the small intestine.

3. The walls of villi, capillaries, and lymphatic capillaries are composed of only one layer of epithelial cells (thin).

4. There are abundant capillaries and lymphatic capillaries in the villi of the small intestine, which can speed up the transportation of substances.

5. The small intestine is the longest section of the digestive tract.

(3) The three main functions of the digestive system:

1. Break down food into small molecular compounds that can be used by the body

2. Absorb these small molecule compounds into the blood

3. Excrete food residues produced after digestion from the body

Food digestion and absorption PPT, part 3: summary of this lesson

(1) Digestion of food:

Digestion: The process by which the body breaks down food (large molecular compounds) into small molecular compounds that can be used by the body.

Digestion methods: physical digestion and chemical digestion.

Small Intestine – is the primary site for food digestion and nutrient absorption.

(2) Absorption of nutrients:

The process in which digested nutrients and some nutrients that do not need to be digested enter the circulatory system through the wall of the digestive tract is called absorption.

There are seven main categories of nutrients contained in food

Food digestion and absorption PPT, Part 4: Consolidation exercises

1. In the digestive tract, the only function of digestion is ＿＿, the one with only absorption is ＿＿, the one with both digestion and absorption is ＿＿＿＿, and the one with neither digestion nor absorption is ＿＿＿＿＿.

2. Some drugs are often taken in capsules made of starch to avoid irritation to the stomach. Judging from the digestion characteristics of starch in the digestive tract, the reason is ( )

A. The stomach can digest starch, allowing the drug to slowly leak out

B． The stomach cannot digest starch, and the capsule can pass through the stomach into the small intestine.

C． Bile cannot digest starch

D． Starch is initially digested in the mouth, making it easier to swallow

3. The doctor removed some liquid from the human digestive tract. After testing, it contained protein, peptides (intermediate products of protein decomposition), vitamins, inorganic salts, water, maltose, starch and fat. The most likely location of these liquids is ( )

A.Upper part of large intestine B.Upper part of small intestine

C. Entrance to the stomach D. Esophagus

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 on 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 (first lesson):

"Digestion and Absorption of Food" PPT (first lesson) Part One: Situation Introduction 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...

File Info

Update Time: 2024-07-11

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

Preview