SKIN
|
|
SKIN
Skin is the largest organ of a human body. Characteristics and structure. Means of temperature control. Skin is one huge sensory perception organ. How skin works.
|
INTRODUCTION
Limits between the frontier of the body and the exterior world.
Insects have an extremely hard skin.
Turtles have “armour-plating” to protect themselves from their surroundings.
Mammals have skins which have sebum and hair.
HUMAN SKIN
Skin is the largest organ of our bodies.
An adult human being has almost 2 square metres of skin.
On any one person’s skin live millions of living-beings.
Structure of the human skin: epidermis and dermis.
Wrinkles.
Between the skin and muscles we find the hypodermis.
Task of the skin.
Sweat glands.
SKIN AND HEAT
The human skin is the best system of refrigeration any mammal has.
Ultra-violet rays. Production of vitamin D. Excess radiation: sunburn or cancer.
Melanin.
Reaction to heat: sweating, dilation of the blood vessels.
Reaction to cold: contraction of the blood vessels; the blood-flow diminishes; the skin stands on end.
Hair. The hair follicle.
SENSORY ORGAN
All our skin is one huge sensory perception organ which acts like a gigantic transmitter constantly sending valuable information to our brain.
Under the skin itself we find tiny little sensory organs.
How stimuli are transmitted from the skin to our brain.
The proportion of sensory organs in the human body.
Skin is also sensitive to pain. Our pain thresh-hold is governed by our gender, age, character and personal experiences.
It protects us from exterior attacks.
SUMMARY |
|
|
|
|
