Home Economics - Junior Secondary 1 - The human body I

TERM: 1^ST TERM

WEEK: 3

CLASS: Junior Secondary School 1

AGE: 12 years

DURATION: 40 minutes each for 2 periods

DATE:

SUBJECT: Home economics

TOPIC: The human body I

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

1.) Discuss the structure and parts of the hair

2.) State the functions of the hair

3.) Outline the care and grooming of the hair

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

INSTRUCTIONAL MATERIALS: Recommended Home economics textbooks for Junior Secondary School 1

INSTRUCTIONAL PROCEDURES: PERIOD 1-2:

NOTE

THE HUMAN BODY

Structure and Parts of the Hair

The structure of the hair consists of several parts, each serving a unique function to ensure the hair's health, growth, and appearance. These parts include:

• Hair Shaft: The visible part of the hair that extends above the skin surface. It is composed of three main layers:
• Medulla: The innermost core of the hair shaft, which is soft and sometimes absent in fine hair. It provides structural integrity to the hair.
• Cortex: The middle layer that contains the protein keratin, which gives the hair its strength, color, and elasticity. The cortex plays a key role in how hair holds shape and texture.
• Cuticle: The outermost layer consisting of overlapping scales of keratin. The cuticle protects the inner layers and helps the hair maintain moisture and smoothness.
• Hair Follicle: The root of the hair, embedded in the skin. The follicle is a tube-like structure from which the hair grows. It contains cells that divide and produce the hair shaft.
• Hair Bulb: The rounded base of the follicle where the hair cells are actively growing and dividing. It contains the papilla, which is rich in blood vessels that nourish the hair and provide nutrients.
• Hair Root: The part of the hair below the surface of the skin, which anchors the hair in the follicle. The root is where the hair grows and is supported by the follicle and surrounding tissues.
• Sebaceous Glands: Located near the hair follicles, these glands produce sebum, an oily substance that helps to lubricate and protect the hair.
• Arrector Pili Muscle: A small muscle attached to the follicle. It contracts in response to cold or emotional stress, causing the hair to stand up (goosebumps).

Functions of the Hair

Hair serves a variety of functions for both physiological and aesthetic purposes:

1. Protection:
   • Scalp Protection: Hair on the scalp protects the sensitive skin from ultraviolet (UV) rays and environmental elements such as dirt, dust, and pollutants.
   • Nasal Hair: Hairs in the nostrils filter dust, dirt, and other particles from the air we breathe, preventing them from entering the lungs.
   • Eyelashes and Eyebrows: These hairs protect the eyes from dust, debris, and sweat, and they help to reduce the amount of sunlight entering the eyes.
2. Regulation of Body Temperature:
   • Hair helps regulate body temperature by providing insulation. The hair traps air close to the skin, which acts as a buffer against heat loss or gain, particularly on the scalp.
3. Sensation:
   • Hair follicles are sensitive to touch. When a hair is moved or touched, the nerves in the follicle can detect the disturbance, which adds to the sensory input the body receives.
4. Expression of Identity and Aesthetics:
   • Hair is a significant aspect of personal appearance and can be used to express individual style, cultural identity, and personality.
5. Hormonal Function:
   • Hair growth is influenced by hormones, and changes in hair growth patterns can be an indicator of hormonal changes in the body, such as during puberty or pregnancy.

Care and Grooming of the Hair

Proper hair care and grooming are essential for maintaining healthy hair, preventing damage, and enhancing its appearance. The steps include:

1. Washing:
   • Shampooing: Use a gentle shampoo suited for your hair type (oily, dry, curly, etc.). Washing removes dirt, oil, and product buildup. However, over-washing can strip the hair of natural oils, leading to dryness.
   • Conditioning: After shampooing, apply a conditioner to help moisturize and detangle the hair. Conditioners also help to smooth the cuticle, adding shine and reducing frizz.
2. Combing and Brushing:
   • Use a wide-tooth comb or a brush with soft bristles to gently detangle wet hair, as wet hair is more prone to breakage. Avoid tugging, as it can cause hair damage and split ends.
   • Brushing: For dry hair, brushing helps distribute natural oils from the scalp along the length of the hair, promoting shine and softness.
3. Drying:
   • Air Drying: Letting hair dry naturally is the healthiest method, as it minimizes heat damage. However, avoid rubbing the hair with a towel, as this can cause friction and lead to breakage.
   • Blow Drying: If using a blow dryer, use the lowest heat setting and a heat-protectant spray to minimize damage.
4. Trimming:
   • Regular trims are important for removing split ends and promoting healthier hair growth. Trimming every 6-8 weeks is recommended for most hair types.
5. Hair Treatments:
   • Deep Conditioning: Use deep-conditioning treatments or hair masks once a week to restore moisture and strengthen the hair, especially for dry or damaged hair.
   • Oil Treatments: Natural oils, such as argan oil, coconut oil, or olive oil, can be massaged into the scalp to nourish and hydrate the hair.
6. Protective Styling:
   • Styles like braids, twists, or buns help to protect hair from environmental damage and breakage. Protective hairstyles are especially important for curly and textured hair.
7. Avoiding Heat and Chemical Damage:
   • Limit the use of heat styling tools (flat irons, curling irons) and chemical treatments (coloring, perming) to reduce hair damage. Always use heat-protectant products before styling with heat tools.
8. Healthy Diet:
   • Eating a balanced diet rich in vitamins and minerals, such as vitamins A, C, D, E, and biotin, can promote healthy hair growth from the inside out.

EVALUATION:

1. What are the main components of the hair structure, and what function does each part serve?
2. Explain how the hair functions in protecting the body and regulating temperature.
3. Describe the steps involved in proper hair care and grooming. Why is each step important?
4. What are the different types of hair treatments, and how do they contribute to hair health?
5. How do external factors such as diet and hair products affect the health and growth of hair?

CLASSWORK: As in evaluation

CONCLUSION: The teacher marks their books and commends them positively