THE SKIN
GRADE VI
INTRODUCTION TO THE SKIN
 The skin is the largest organ in the human body
 The skin is part of the integumentary system

(this is the system that includes nails, hair, sweat glands and skin)
 It covers and protects everything inside your body. Without skin, people's muscles, bones, and organs would
be hanging out all over the place. Skin holds everything together.
FUNCTIONS OF THE SKIN
Protecting the body:
Maintaining temperature:
The skin forms a barrier that keeps
harmful substances outside the body and
also keeps useful substances inside the
body
The skin helps maintaining body
temperature. Sweating allows our body to
cool. If you feel too cold, the blood
vessels contract below the skin, allowing
you to maintain heat and stay warm.
FUNCTIONS OF THE SKIN

Eliminating waste:
 Perspiration (sweat) contains dissolved waste
materials the skin helps eliminate these form the
body
 Gathering information (sensory):
 Nerves in the skin, the sense of touch allows us to
feel and interact with the environment and also
respond to physical threats
 Producing vitamin D:
 Vitamin D is essential for healthy bones, the skin can
produce vitamin D using sunlight
STRUCTURES OF THE SKIN
 The skin has two layers: An outer layer and an inner
layer
 Epidermis:

The epidermis is the outer layer of the skin. New cells
form deep in the epidermis and as they mature
upward until they die. They then become of the
epidermal surface layer. Cells stay in the surface layer
for 2-3 weeks and then they are shed.

Melanin: the melanin in the epidermis gives colour
to the skin. Melanin is produced by cells deep in the
epidermis

Pores are openings in the epidermis that allow sweat
to reach the surface.
STRUCTURES OF THE SKIN
 Dermis:
 The dermis is the inner layer of the skin. Underneath the dermis is fat, and above the dermis
is the epidermis.
 The dermis includes nerves, blood vessels, sweat glands, hair follicle and oil glands.
 Strands of hair grow in follicles that are found in the dermis