Lesson Notes By Weeks and Term - Senior Secondary 2

TERM – 1^ST TERM

WEEK FIVE

Class: Senior Secondary School 2

Age: 16 years

Duration: 40 minutes of 5 periods each

Date:

Subject: HEALTH EDUCATION

Topic: DIGESTIVE SYSTEM

SPECIFIC OBJECTIVES: At the end of the lesson, pupils should be able to

I.) Define digestion

II.) Discuss the stages of digestion

III.) Describe the human digestive system

INSTRUCTIONAL TECHNIQUES: Identification, explanation, questions and answers, demonstration, videos from source

INSTRUCTIONAL MATERIALS: Videos, loud speaker, textbook, pictures,

INSTRUCTIONAL PROCEDURES

PERIOD 1-2

NOTE

DIGESTIVE SYSTEM

Digestion is the process by which food is broken down into smaller, more absorbable molecules that can be used by the body for energy, growth, and repair. It involves both mechanical and chemical processes that occur throughout the digestive system.

The main stages of digestion include:

1. Ingestion: The process of taking food into the mouth.
2. Mechanical Digestion: Food is mechanically broken down into smaller pieces through chewing (mastication) in the mouth and mixing and churning movements in the stomach.
3. Chemical Digestion: Enzymes and acids break down complex molecules in food into simpler forms that can be absorbed by the body.
4. Absorption: The small intestine absorbs the resulting nutrients—such as sugars, amino acids, fatty acids, vitamins, and minerals—into the bloodstream for distribution throughout the body.
5. Elimination: Undigested food residues, along with waste products and bacteria, are eliminated from the body as feces through the rectum and anus during defecation.

The Human digestive system

The human digestive system is a complex biological system responsible for processing food, extracting nutrients, and eliminating waste. It consists of several organs and structures that work together to facilitate the digestion and absorption of food.

1. Mouth: Digestion begins in the mouth, where food is ingested and mechanically broken down by chewing (mastication). Salivary glands secrete saliva, which contains enzymes (such as amylase) that start the chemical digestion of carbohydrates.
2. Esophagus: The esophagus is a muscular tube that transports food from the mouth to the stomach through peristaltic contractions, rhythmic waves of muscle contractions that propel the food downward.
3. Stomach: In the stomach, food is further broken down and mixed with gastric juices containing hydrochloric acid and enzymes (such as pepsin) that digest proteins.
4. Small Intestine: The small intestine is where most of the digestion and absorption of nutrients occur. It consists of three segments: the duodenum, jejunum, and ileum. Enzymes from the pancreas (such as amylase, lipase, and proteases) and bile from the liver aid in the breakdown of carbohydrates, fats, and proteins.
5. Pancreas: The pancreas is both an endocrine gland (producing hormones such as insulin and glucagon) and an exocrine gland (producing digestive enzymes). It secretes pancreatic enzymes into the small intestine to further break down carbohydrates, proteins, and fats.
6. Liver: The liver is the largest internal organ and has multiple functions in the digestive process. It produces bile, which is stored in the gallbladder and released into the small intestine to aid in the digestion and absorption of fats.
7. Large Intestine (Colon): The large intestine receives undigested food residue (mainly fiber, water, and bacteria) from the small intestine. It absorbs water and electrolytes from the residue, forming feces.
8. Rectum and Anus: Feces are stored in the rectum until they are eliminated from the body through the anus during defecation.

EVALUATION: 1. Define digestion

2. Mention the 5 stages of digestion.
3. Briefly discuss the human digestive system

CLASSWORK: As in evaluation

CONCLUSION: The teacher commends the students positively