Skin being the largest sense organ of the body among the 5 sense organs namely Vision , Hearing , Taste , smell and Touch.
It weighs about 4-5 kg and comprises of about 16% of the body weight.
Outlines the whole outer body by covering an area of around 1.7 m² (approx).
Skin can be divided into 3 layers namely Epidermis , Dermis , Hypodermis.
FUNCTIONS :-
1) It acts as a barrier in function by stopping all the external agents such as Bacteria , Viruses and other antigens present in the environment from directly entering in the body and disturbing the internal Homeostasis.
2) It also functions to provide the colour that every human holds via its EMU (epidermal Melanin Units) present in epidermis.
One EMU consists of one melanocyte supplementing melanin to 36 keratinocytes.
The number of EMU are same in all individuals around the world. It is the activity of the units which decides the skin colour of an individual.
3) It also functions as a sensory organ in the body with the help of some specialised cells and bodies . The sensory modalities percieved by the skin are Touch , Pressure , Vibration , Pain , Heat and Cold respectively.
a) Touch – percieved by the Meissner Corpuscles.
b) Thermal Sensation – percieved by Ruffini’s Corpuscles
c) Pressure and Vibration – percieved by Pacinian Corpuscles
d) Pain – percieved by free nerve endings.