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 temperature 3. Manufacture Vitamin D 4. Nerve receptors 5. Temporary storage 6. Screen-out ultraviolet radiation 7. Special absorptive properties

Structure of the Skin Epidermis Dermis Outermost covering Avascular True skin Connective tissue Vascular

Structure of the Skin © 2014 Cengage Learning.

Epidermal Cells 1. Keratinocytes 2. Merkel cells 3. Melanocytes 4. 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 Name three functions of the skin What are the two main layers of the skin? (what is the third layer that is not considered part of the integumentary system?) 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 Athlete’s foot Dermatitis Common and chronic disorder of sebaceous glands Athlete’s foot Contagious fungal infection Dermatitis Inflammation of the skin

Disorders of the Skin Eczema Impetigo Psoriasis 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 Urticaria (hives) Boils (carbuncles) 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 Herpes 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 Shingles (herpes zoster) 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?