Human skin

It is the largest organ in human body which has all 4 types of basic tissues. it is divided into 2 primarily
1) Epidermis

has stratified squamous epithelium
inner most layer is known as basal layer / malphigian kayer
the layer above it is spinous layer
the layer above it is granular layer
the layer above it is clear layer with n nucleated cells
the outermost layer has keratinized layer with dead cells
malphigian layer has melanocytes which secrete melanin
epidermis folds inward and forms the following
1. Hair follicle ( support the hair )
2. Sweat gland
3. Sebaceous gland
some sensory receptors are also present
1. Free nerve ending
2. Merkel disc

has soft connective tissue
erector pilli muscle is connected to hair follicle
has collagen fibers and elastin fibers
rich in blood vessels and lymphatic vessels
has various receptors
1. Pacinian particle
2.Organ of ruffini
3. Krause's bulb
4.Meissner's particle

Functions of skin
1. protects body from dehydration , friction, UV rays by keratinized cell layers in epidermis
2. prevent water loss through epidermis
3. due to melanin in epidermal cells UV protection is given
4. function as a sensory organ
5. function as heat / pain insulator is important to regulate body temperature
7. sweat glands secrete sweat and take part in excretion
8. sebum secreted by sebaceous glands keep skin surface water proof or flexible . further it kills micro organisms.
9. skin synthesizes vitamin D using UV
10. gives protection from injuries and stores energy

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Shafna samad