Integumentary System

Integumentary System

Skin and its appendages– Hair– Nails– Sebaceous glands– Sweat glands

Integumentary means “covering” 3,000 square inches of surface area

Functions of the Skin

1. Covering 2. Regulate body

temperature3. Manufacture Vitamin D4. Nerve receptors5. Temporary storage6. Screen-out ultraviolet

radiation7. Special absorptive

properties

Structure of the Skin

Epidermis – Outermost covering– Avascular

Dermis– True skin– Connective tissue– Vascular

Structure of the Skin

© 2014 Cengage Learning.

Epidermal Cells

1. Keratinocytes2. Merkel cells3. Melanocytes4. Langerhans cells

Epidermal Layers

Stratum corneum Stratum lucidum Stratum granulosum Stratum spinosum Stratum basale (basement membrane)

Dermis Also called corium Thicker, inner layer

of the skin

Many nerve receptors

Blood vessels and heat regulation

Subcutaneous Layer Also called hypodermal

layer Lies under dermis

Not a true part of the integumentary system

Attaches integumentary system to the surface muscles underneath

Checkpoint Quiz #1

1. Name three functions of the skin

2. What are the two main layers of the skin? (what is the third layer that is not considered part of the integumentary system?)

3. What is one difference between the epidermis and the dermis?

Appendages - Hair

Root shaft Outer cuticle layer Cortex Inner medulla Hair follicle Arrector pili muscle

Appendages - Hair

© 2014 Cengage Learning.

Appendages - Nails

Hard structures covering the dorsal surfaces

of the last phalanges of the fingers and toes Nail bed or matrix Diseases and nail color

Appendages - Nails

© 2014 Cengage Learning.

Appendages - Sweat Glands

Also called sudoriferous glands

Perspiration is 99% water Perspiration is excreted

through pores Under the control of the

nervous system 500 ml water lost per day

through the skin Ceruminous or wax glands

Sebaceous Glands

Secrete sebum which is thick, oily substance Sebum lubricates the skin, keeping it soft

and pliable

Microorganisms

Intact skin is the best way to protect against pathogens

Most skin bacteria are associated with hair follicles and sweat glands

Hand washing Most effective action to prevent spread of disease▪ 20 seconds for washing hands▪ 2-4 minutes for infectious material

Aging Skin

Becomes more fragile and dry Loss of elasticity Less effective body temperature control Melanocytes decrease Physiological changes can impact self-worth

Checkpoint Quiz # 2

1. What is the role of the sebaceous glands?

2. Through what layer(s) of the skin do hair follicles reside?

3. What are two characteristics of aging skin?

Disorders of the Skin

Acne vulgaris– Common and chronic

disorder of sebaceous glands

Athlete’s foot– Contagious fungal

infection Dermatitis

– Inflammation of the skin

Disorders of the Skin

Eczema– Acute or chronic, noncontagious

inflammatory skin disease Impetigo

– Acute, inflammatory, and contagious skin disease

Psoriasis– Chronic inflammatory skin disease

(reddish patches

covered by silvery-white scales)

Disorders of the Skin

Ringworm– Highly contagious fungal

infection Urticaria (hives)

– Intensely itching wheals or welts

Boils (carbuncles)– Painful, bacterial infection

of the hair follicles or sebaceous glands

Disorders of the Skin

Rosacea– Common inflammatory

disorder (chronic redness and irritation to the face)

Herpes– Viral infection that is

usually seen as a blister

Disorders of the Skin

Genital herpes– Virus that may appear as a

blister in the genital area

Shingles (herpes zoster)

– Skin eruption due to a viral infection of the nerve ending

Disorders of the Hair and Nails

Head lice– Parasitic insects

Ingrown nails– Common nail problem

Disorders of the Hair and Nails

Fungal infections– Infections of the nail

Warts– Viral infections that affect the

skin surrounding or underneath the nail

Skin Cancer

Basal cell carcinoma Squamous cell carcinoma Malignant melanoma Skin and sun exposure

Burns

Rule of nines First-degree burns Second-degree burns Third-degree burns

Skin Lesions

Pressure ulcer (decubitus ulcers)– Stage I– Stage II– Stage III– Stage IV

Checkpoint Quiz #3

1. Explain what the “rule of nines” is:

2. Pick two skin disorders (not any type of herpes) and explain what each one does to the skin.

3. Within the powerpoint the term “dorsal surface” was used, what does the term “dorsal” mean?