Skin for Kids

Which is the largest organ in your body? If you’ve guessed it to be the liver, you are partially right. But this largest organ we are referring to right now has a surface area of about around 2m² and is probably the largest surface area in our body that is completely exposed to the outside world. You guessed about this time we are talking about the skin!

Skin plays a vital role in keeping the contents of our bodies together. Without further delay, let us look into the details of this super-awesome organ, and jump right in!

A Glowing Skin

What is the Integumentary System?

The skin has multiple layers (we will look into these shortly) and several related structures that help its effective functioning. All of these components can be collectively called the integumentary system. 

Components of the integumentary system comprise:

1. Skin and its layers

2. Hair

3. Nails and 

4. Exocrine glands (glands that secrete substances on the skin surface)

Skin 

What is Skin?

Skin is the largest organ of our body protecting us from injuries through the external environment. They also keep the contents of the body in a well-organised manner.

Skin is primarily made up of water, proteins, fats, and important minerals.

On observing the skin under the microscope, you would notice square-shaped cells called epithelial cells arranged one on top of the other (known as stratified squamous epithelial cells). Hair follicles and glands open to this surface. Below you will find a detailed diagram.

Epithelial Cells

Structure of the Skin

The skin has several layers inside out that help its function. Mostly it is divided into 3 layers:

1. Epidermis (‘Epi’ meaning above)

2. Dermis

3. Hypodermis (‘Hypo’ meaning below)

These layers are made of different cells and structures each performing its specific function.

Epidermis

• The outermost layer of the skin is protective in function, act as first line of denfense again foreign antigens.

• The epidermis has five layers - 

1. Stratum corneum

2. Stratum lucidum

3. Stratum granulosum

4. Stratum spinosum

5. Stratum basale 

• It is made up of keratin which is a type of protein.

• Cells of this layer are dry and get replaced by newer cells periodically.

• Cells of the epidermis contain melanin (a special pigment) which gives us different skin tones.

• They also contain various special types of cells that help their protective action.

Epidermis of the Skin

Dermis

• Cells of this layer contain elastin and collagen (again, various proteins) which help skin strength and flexibility.

• This layer contains blood vessels that help the healthy functioning of the cells.

• It contains specialised nerve endings which give it a ‘sense of touch

• Sweat and oil glands are also present in this layer.

• It contains roots of hair follicles thereby promoting hair growth.

Crossectional View of the Dermis

Hypodermis

• The deepest layer of skin connects skin to muscle tissues and bones.

• It is a fatty layer providing a cushion effect to the contents of our body.

• It helps connect nerves and blood vessels from the dermis to the main branches connecting the rest of the body.

• It has specialised receptors (like a sensor) for extreme temperatures.

• It acts as an insulation layer (protecting the body from extreme temperatures).

Structure of the Hypodermis

Specialised Structures Present in the Skin Layers

1. Hair follicles

2. Melanocytes (cells producing melanin pigment)

3. Sweat glands

4. Sebaceous glands (oil-producing glands)

5. Specialised protective cells prevent infections.

Functions of Skin

• Provides us with a sense of touch.

• Helps the body’s temperature regulation.

• Storage of energy as a fat layer (subcutaneous fat present beneath the skin).

• Protects us from harmful microbes around us.

• Produces melanin which is important to protect from harmful UV radiation of the sun.

• Protects us from cancer.

How to Maintain Good Skin Health?

Now that we’ve understood how important skin is for us, it is necessary to maintain this valuable organ and protect it from unnecessary damage. Some ways to maintain good skin health are :

• Always use sunscreen.

• Staying indoors to prevent too much tanning.

• Consuming vegetables and fruits.

• Drinking plenty of water.

• Managing stress and getting proper sleep.

A Healthy Skin

Summary

The skin sense organ is one of the most important structures of the human body, known as the integumentary system. It comprises skin, hair, nails and the exocrine associated with it. Skin is made of very thin and elastic 7 layers often referred to as the 7 layers of skin. Some of the important layers are the epidermis, dermis and hypodermis. Functions of the skin include a sense of touch and temperature, protection against harmful radiations, and fat storage. It is important to consume green leafy vegetables, fruits, etc., to maintain the well-being of the overall integumentary system.