Biology
Integumentary System
Human Integumentary system is the outer layer of the body comprising of skin, hair, nails, nerves and associated glands. It protects the body from infection, injury, sunlight etc. It regulates body temperature. It stores water, glucose, fat and vitamin D and supports immune system. It excretes waste from body. It acts as barrier between internal and external environment thus providing protection.
Parts of integumentary system
• Skin
• Hair
• Nails
• Glands
Skin
• Skin is the largest organ of the body
• The 3 layers of the skin are epidermis, dermis and hypodermis layer
• Epidermis is the outermost layer of the skin. It has the cells keratinocytes which has protein keratin that makes skin waterproof and strengthens it, the cells Langerhans which helps in immunity and the cells melanocytes which has melanin gives dark colour to skin and protects from ultra violet light
• Dermis is the thickest middle layer of the skin containing oil glands, sweat and hair follicles. It synthesizes vitamin D to absorb calcium
• Hypodermis is the bottom fatty layer of the skin that helps in insulating the body. It protects the inner organs. The fat stored gives energy
Functions of skin
• Skin helps in preventing the loss of water from the body
• It helps in regulating the body temperature
• The sensation can be felt to outer stimuli
• It protects the body from infection
• It protects the body from injury
Hair
• Hair is produced by epidermis but grows its roots into dermis
• The visible hair is hair shaft
• The tube-like structure that keeps hair in skin is hair follicle
• The hair bulb located under skin is responsible to hair growth
• The eyelashes and eyebrows protect from dirt
• The hair on head helps in keeping heat of the body
Nails
• Nails are on the upper surface of fingers and toes
• Nails protect fingers and toes
• Nail plate is the visible portion of the nail
• Nail bed is the skin under the nail plate
• Nails enhances movements precision
Glands of integumentary system
• Sebaceous glands are oil glands producing oil on the face
• Sudoriferous glands (sweat glands) secrete sweat
• Ceruminous glands are glands in ear that secrete wax
• Mammary glands produce milk
How the integumentary system is affected
• Melanoma is a form of skin cancer
• Cellulitis is a skin infection causing swelling and pain
• Psoriasis is a skin disease causing scaly patches with itchiness
• Acne occurs when oil, bacteria, dead skin block the pores
• A fungal infection of toenails is Onychomycosis
• Hyperhidrosis is excessive sweat from eccrine glands
• Eczema is a skin disease
• Based on the degree of level of burn the skin gets affected accordingly
• Folliculitis is inflammation of hair follicles