skin notes
DESCRIPTION
Ski notes for Grade 8 healthTRANSCRIPT
National Geographic Skin
Integumentary System - Skin, hair, and nails protect our insides from the outside.
The epidermis is the outer layer of skin. The outer cells are dead, and all the cells are filled with keratin, a protein that gives the skin its rough, leathery texture, and makes it waterproof. The dermis is the inner layer of
skin. The cells that make it up are alive, and it contains nerves, blood, and lymph vessels. The nerves allow the reception of environmental signals. The blood vessels help regulate body temperature, and the lymph helps protect against infection. A layer of fat below the dermis stores food for energy.
The Integumentary System
Skin-vertical section 1 Epidermis
2 Dermis
3 Subcutaneous fat
4 Nerve ending
5 Capillary loop
6 Hair follicle
7 Sebaceous gland 8 Hair
9 Hair erector muscle
10 Sweat duct
11 Sweat pore
12 Nerve ending-touch
13 Sweat gland
14 Nerve ending -pressure))
A hair root is produced at the base of the hair follicle, which is a deep pocket that extends into the dermis. The hair shaft (the part of the hair outside the skin) is made of keratin and needs no nourishment, because it is no longer alive. Oil from glands in the skin keeps the hair shaft from drying out and breaking off.
Hair
Nails form from root cells in the epidermis. As new cells form, the nail grows longer. Nails are also made up of keratin.
Nails
Glands release secretions through ducts. The main glands are the sweat glands and the oil glands.
Sweat glands release excess salts, water, and urea to regulate body temperature. If the body is too hot, the sweat glands release sweat, which evaporates and cools the body.
The oil glands release sebum, which helps keep the skin soft and waterproof.
Glands
Urea carries excess heat away from the body
A pigment, determines if the skin will be light or dark, and it protects the skin from harmful ultraviolet light by absorbing it.
Melanin - Skin Pigment
Melanocyte - Melanin producing cells
Melanin
Attachments
Causes of Acne.flv