The Integumentary
System
Integumentary System
• Hair
• Skin
• Nails
Functions of Integumentary System
• Functions
– Protective barrier against infection and injury
– Regulates body temperature
• Evaporation of sweat from surface of body cools us off
– Removes waste products
• Sweat contains water, electrolytes, and wastes
– Protection from ultraviolet radiation
– Sensory Organ
• Pressure
• Heat and Cold
• Pain
Structure of the Skin
• The skin is made of several layers
– Epidermis
– Dermis
– Hypodermis
Structure of the Skin
Epidermis
• The epidermis is the top layer of the skin
• The epidermis contains 2 layers
– Top layer is flattened dead cells
– Bottom layer is made of living cells
• These cells divide rapidly pushing upward
• Cells produce Melanin and Keratin
– Melanin is a protein pigment that helps protect us from sun
and gives us our color
– Keratin is a tough fibrous protein that gives skin its strength
Structure of the Skin
Dermis
• The Dermis is the inner layer of the skin
– Lies beneath epidermis
• The dermis contains collagen fibers
(elasticity, blood vessels, nerve endings &
sensory receptors, smooth muscles, and hair
follicles an two types of glands
– Sudoriferous glands = sweat glands
– Sebaceous glands = oil glands
• Makes skin flexible and waterproof
Structure of the Skin
Hypodermis
• Lies beneath Epidermis and Dermis
• Contains Adipose (Fat) and ConnectiveTissues
that help insulate the body and hold the skin
in place
Hair
• Hair gives protections from sun and provides
insulation from cold
• Hair is produced by tubelike structures called
the hair follicles
– Hair follicles produce shaft which is filled with keratin
and melanin (strength and color)
– Hair follicles are in close contact with sebaceous or oil
glands
• Natural conditioner
– Many waste products including drug metabolites are
released in hair shaft as well
Nails
• Nails grow from rapidly dividing cells known
as the nail root
– Keratin producing cells create tough platelike
structure of the nail
• Protects nerve ends and sensory receptors in fingertips
• Nails grow at an average of 3mm per months
Skin Cancer
• Skin Cancer is abnormal growth of skin cells
• Caused by overexposure to UV radiation from
sunlight
– Some People are more likely to get skin cancer
• Genetics/skin complexion
• Protect Yourself
– Sunblock, hats, self checks, doc checks ect..