Integumentary System Biology Grade-9. Prepared by the teacher: Ronak Ahmed Hassan 2012-2013 International School / Duhok. - Is there a partly dead part in your body?. - Is it important to keep you alive?. Here are some clues: It comes in many colors. It is the largest organ in the body.
Integumentary SystemBiology Grade-9
Prepared by the teacher: Ronak Ahmed Hassan
International School / Duhok
- Is it important to keep you alive?
Here are some clues:
Now, what do you guess?........
Your skin, hair, and nailsmake up your integumentary system.
What is the function of integumentary system?
Covers your body and helps you maintain homeostasis.
Small organs in the skin called sweat glands make sweat. Sweat is a salty liquid that flows to the surface of the skin. As sweat evaporates, the skin cools.
It determined by a chemical called melanin.
If a lot of melanin is present, skin is very dark
If little melanin is present, skin is very light
What is the importance or the role of melanin?
Melanin absorbs ultraviolet light from the sun.
So melanin reduces damage that can lead to skin cancer
Can we say only light skin is vulnerable to cancer?
No, all skin, even dark skin, is vulnerable to cancer. Skin should be protected from sunlight whenever possible.
Beneath the surface, your skin is a complex organ made of blood vessels, nerves, glands, and muscles.
Oil glands: release oil that keeps hair flexible & waterproofs the epidermis.
Carry messages to and from the brain
In the dermis make hair
Muscle fibers: Attached to hair follicle can contract & cause the hair to stand up
Transport substances & help regulate body temperature
Release sweat to cool the body. Sweating is also a way to remove waste materials from the body.
What is the largest organ of your body?
The skin of an adult covers an area of about 2m 2
You see it when you look at your skin
1- On the palms of your hands.
2- on the soles of your feet
Where is it thicker?
Most cells in the epidermis are dead
These cells are filled with a protein called Keratin.
What is the function of Keratin?
Keratin helps make the skin tough.
The dermis lies beneath the epidermis
It has many fibers made of a protein called collagen
What is the function of these fibers?
Describe the dermis. How does it differ from the epidermis?
The dermis is the layer of skin that lies beneath the epidermis. It is composed of a protein called collagen, while the epidermis contains keratin.
They are important parts of the integumentary system
Like skin, hair & nails are made of living and dead cells
Where the hair & nails are formed?
The hair forms at the bottom of a tiny sac called a hair follicle.
The nail grows from living cells in the nail root at the base of the nail.
When the hair grow, where the new cells will be added to?
When the hair grows, a new cells are added at the hair follicle. Older cells get pushed upward.
What part of hair is the living part and which one is dead?
The only living cells in a hair are in the hair follicle. The rest are dead part
What are the functions of hair?
How hair contribute in the regulation of body temperature?
A tiny muscle attached to the hair follicle contract. If the follicle contains a hair, the hair stands up. The lifted hairs work like a sweater. They trap warm air around the body.
It became longer as new cells form.
The nail’s function:
What is the content of the hair?
A hair is made up of layers of dead, tightly packed, keratin-filled cells.
Skin is often damaged. Fortunately, your skin can repair itself.
What is the causes of skin cancer?
If the damage of skin was in the genetic material in skin cells, this can cause skin cancer.
What is the causes of acne?
Skin may also affected by hormones that causes oil glands in skin to make too much oil. This oil combines with dead skin cells & bacteria to clog hair follicles which causes acne.
Describe how a cut heal?
Bacteria-fighting cells then come to the area to kill bacteria.
Describe how nails grow.