A&PA&PChapter 20Chapter 20

Integumentary SystemIntegumentary System

What is the largest organ What is the largest organ in the body?in the body?

The skin! The skin is part of the Integumentary The skin! The skin is part of the Integumentary System and contains 12-15% of the body’s System and contains 12-15% of the body’s total weight.total weight.

Two distinct layers occur in the skin.Two distinct layers occur in the skin. Dermis – connective tissue located under the Dermis – connective tissue located under the

epidermis ; contains nerve endings, sensory epidermis ; contains nerve endings, sensory receptors capillaries and elastic fibers.receptors capillaries and elastic fibers.

Epidermis – the outer most layer of the skin Epidermis – the outer most layer of the skin which contains pigmentwhich contains pigment

Functions of the Integumentary Functions of the Integumentary SystemSystem

The Integumentary system has multiple roles in The Integumentary system has multiple roles in homeostasis.homeostasis.

ProtectionProtection – the skin protects internal structures from – the skin protects internal structures from harmful agents harmful agents

Melanin Melanin – – protects the underlying structures from protects the underlying structures from ultraviolet lightultraviolet light

Produces Vit DProduces Vit D works with calcium to benefit the works with calcium to benefit the bodybody

Protects the body from excess fluid and electrolyte Protects the body from excess fluid and electrolyte lossloss

Functions of the Integumentary System Functions of the Integumentary System continuedcontinued

Regulation – Regulation – the skin serves as a temperature the skin serves as a temperature regulatorregulator

Too hot? Sweating and vasodilatation Too hot? Sweating and vasodilatation Too cold? Shivering and vasoconstrictionToo cold? Shivering and vasoconstriction

Functions of the Integumentary System Functions of the Integumentary System continuedcontinued

Sensory receptionSensory reception – – Millions of receptors are located in the skin for Millions of receptors are located in the skin for

sensations of pain, touch heat, cold and sensations of pain, touch heat, cold and pressure.pressure.

Receptors send messages to the brain which Receptors send messages to the brain which trigger a responsetrigger a response

Functions of the Integumentary Functions of the Integumentary System continuedSystem continued

Secretion Secretion – – Sweat glands produce sweat.Sweat glands produce sweat.

Sebaceous glands secrete oil for Sebaceous glands secrete oil for lubrication.lubrication.

Not just skin…Not just skin…

The Integumentary system is comprised of The Integumentary system is comprised of accessory structuresaccessory structures..

NailsNails Sebaceous glandsSebaceous glands Sweat glandsSweat glands HairHair

Lifespan considerationsLifespan considerations

ChildrenChildren Skin conditions can be acute or chronic, local or Skin conditions can be acute or chronic, local or

systems and some are congenitalsystems and some are congenital Skin infections present as systemic infections with Skin infections present as systemic infections with

fever and malaise.fever and malaise. Children under 10, chap more easyChildren under 10, chap more easyOlder AdultOlder Adult Skin looses elasticity causing wrinklesSkin looses elasticity causing wrinkles Watch for malignant skin lesionsWatch for malignant skin lesions Grey hair, dry and brittleGrey hair, dry and brittle Nails become flat , discolored, dry and brittleNails become flat , discolored, dry and brittle

Patient educationPatient education

Skin care is an important part of hygiene.Skin care is an important part of hygiene. Moisturizing is important.Moisturizing is important. Importance of sunscreenImportance of sunscreen Avoid sunburn.Avoid sunburn. Medications, such as antihypertensive Medications, such as antihypertensive

medication, make patients more susceptible to medication, make patients more susceptible to sunburn.sunburn.