Integumentary System

Objectives Name and describe the two layers of the skin. Name and describe the layers of the epidermis. Describe the generation of new cells in the epidermis. Explain the role of melanin in the skin. Discuss potential normal and abnormal skin colors and identify the cause of

each. Explain the five functions of skin. Describe the structure and function of hair. Describe the structure of nails. List some common nail abnormalities and their causes. Name the two types of sweat glands and discuss the structure and function of

each. Differentiate between sebaceous and ceruminous glands.

Identify the location and structure and function of each.

Discuss the three classes of burns, including the complications of each. Describe the three types of skin cancer.

Cutaneous Membrane

Epidermis

Dermis

Hypodermis

Integumentary System Skin

Appendages

Hair

Nails

Skin Glands

Integumentary System Consists of 2 Layers

Epidermis Outermost layer

Stratified squamous epithelial tissue

NO Blood vessels

Dermis Connective tissue

Collagen fibers (strengthen)

Elastin fibers (elasticity)

Reticular(bind collagen and elastin)

Hypodermis

Epidermis Skin’s outermost layer

Receives oxygen and nutrients from dermis

Layers of Epidermis

View animation on “The generation of skin layers”

Stratum basale

Stratum corneum

Layers of the Epidermis Stratum Basale

Innermost layer

Columnar stem cells

Continuing undergo mitosis

Produce new skin cells

Layers of the Epidermis New skin cells push older cells upward

Older cells stop dividing

Produce keratin Replaces cytoplasm and nucleus

Cells flatten and die

Stratum Corneum is formed 30 layers of dead,flat cells

Barrier to water entering body

Allows for evaporation

Multiple layers help resist abrasion

Dermis Blood vessels

Sweat glands

Sebaceous glands

Nerve endings

Hair follicles

Hypodermis Areolar tissue

Adipose tissue

Binds skin to underlying tissue

Animation- Skin Layers Student Resources

Animation- Chapter 5

“Generation of Skin Layers”

Skin Color Melanocytes produce melanin.

Melanin protects the nucleus (DNA) from ultraviolet (UV) exposure.

The amount and type of melanin determines skin color.

Melanin 2 types

Pheomelanin (reddish color) Eumelanin (brown-black color)

Disorders can cause: Abnormal skin color Cyanosis Jaundice Bronzing Albinism Erythema Pallor Hematoma

Albinism Genetic lack of melanin

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Functions of the Skin (5) Protection

Barrier

Vitamin D production

Sensory perception

Thermoregulation

Nerves in the dermis cause blood vessels to dilate or constrict

Regulate heat loss

Function of Skin- Protection Blocks microorganisms

Blocks harmful chemicals

Secretes a surface film

Blocks toxins

Inhibit growth of microorganisms

Blocks UV rays

Question

New skin cells produce which tough, fibrous protein?

A. CollagenB. ElastinC. MelaninD. Keratin

HairShaft

Hair follicle

Hair bulb or root

Papilla

Arrector pili

Hair Extends above the skin’s surface.

Hair follicle Lies within a sheet of the epidermis

Rich nerve and blood supply

Hair root Dermis

Where growth occurs

Papilla Base of hair

Cluster of connective tissue and blood vessels

Nourishes each hair

HairWhat causes it to “Stand on End?” Arrector Pili Muscle

Attached to each hair follicle

Bundle of smooth muscle

Cold or fear

Muscles contract

Hair becomes more upright

Nails

Nail body

Cuticle

Lunula

Nail bed Nail root

Nails Consists of densely packed Heavily keratinized epithelial cells Nail Body

Visible part of the nail

Cuticle Fold of skin surrounding the nail body

Lunula Crescent shaped white area at the base of the nail

Nail root Proximal end Hidden underneath overlying tissue

Nail bed Layer of epithelium under nail Pink Rich in blood supply

Nails Growth

Newly keratinized cells

Added to nail root

Nail is pushed forward

Nails Disorders

Clubbing

Lung disease

Cyanosis

Flattened or concave nail beds

Dark lines beneath nail

White nails

Yellowish nails

Pale nail beds

Sweat Glands

Eccrine gland

Apocrine gland

Sebaceous gland

Sweat Glands 2 types

Eccrine

Apocrine

Sweat Glands- Eccrine Contain a duct that leads from the secretory portion to the skin’s

surface Located in

Palms Soles Forehead Upper Torso

Produce sweat Maintain a constant core temperature Eliminates wastes

Ammonia Lactic Acid Uric Acid Potassium

Sweat Glands- Apocrine Contain a duct that leads to a hair follicle

Begin to function at puberty

Located

Axillary

Anogenital (groin) region

Scent glands

Respond to stress and sexual stimulation

Strong order occurs when there is accumulation

Bacteria degrade substances in sweat

Sweat Glands- Effect on Aging Decline in number of sweat glands

Decline in output of existing sweat glands

Interfere with ability to “cool down”

Develop heat stroke

Sweat- Phone Question Approximately how much fluid does the body lose per

day in insensible perspiration?

Sebaceous Glands Open into a hair follicle

Secrete oily substance- Sebum

Keep skin and hair from drying out

Antibacterial

Antifungal

Production increases during adolescence

Accumulation in gland ducts

Blackheads

Pimples

Question

Which glands secrete sweat onto the skin’s surface?

A. Apocrine glandsB. Eccrine glandsC. Sebaceous glandsD. Ceruminous glands

First-Degree Burn Involves only the

epidermis

Causes redness, slight swelling, and pain

Often results from sunlight (sunburn)

Second-Degree Burn Involves the epidermis and part of

the dermis

Results in blisters, severe pain, and swelling

May result in scarring

May appear red, white, tan

Third-Degree Burn Extends into the

subcutaneous layer

May not be painful initially

May appear white or black

and leathery

Often requires skin grafts

Third Degree Burn Complications

Infection

Fluid loss

Lack of thermoregulation

Nerve endings in dermis destroyed

Prevents sensory input from reaching brain

Painless- initially

Third Degree Burn Eschar

Dead tissue resulting from a burn

Secretes toxins and promotes bacterial growth

Restrict circulation

Question- Kahoot.it

Skin and Burns Kahoot

Rule of Nines

Quiz Review Know how the skin regulates body temperature

Know what the classifications of burns are

Know the layers of skin and what they contain

Know the life cycle of an epidermal cell

Know disease clubbing of nails is associated with

Know which layer of skin is nourished by diffusion

Know what melanin does

Know what eccrine glands are

Know what apocrine glands are

Know what the papilla does

Homework Read Chapter 5- Integumentary System

House Call- Due on Test Day- Quiz Grade

Quiz – October 6, 2016

Test Chap 5/6- October 11, 2015

Extra Credit – 4 points on test (2 questions)

Chapter 5 Workbook- Due on test day

Watch Animations in Davis Book

Under Student Resources