Chapter 5 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 Skin Covering Regulate body temperature Manufacture Vitamin D Nerve receptors

Functions of Skin Temporary storage Screen out ultraviolet radiation Special absorptive properties

Structure of the Skin Epidermis Dermis Outermost covering Avascular Connective tissue Vascular / Receptors

Structure of the Skin

Epidermal Cells Keratinocytes- gives strength Merkel cells- sensory touch Melanocytes- protect against UV Langerhans cells- part of immune

Epidermal Layers (5) Stratum germinativum Stratum spinosum Stratum granulosum Stratum lucidum Stratum corneum

Dermis Thicker, inner layer of the skin Many nerve receptors Blood vessels and heat regulation

Subcutaneous Layer Lies under dermis Not a true part of the integumentary system Attaches integumentary system to the surface muscles underneath

Different parts of the skin- Hair Root shaft – part that is showing (pg. 76) Medulla- Inner part Hair follicle-embedded Arrector pili muscle

Appendages Nails Hard structures covering Nail bed or matrix phalanges of the fingers and toes Nail bed or matrix Diseases and nail color

Appendages Sweat Glands Perspiration 99% water Perspiration is excreted through pores Under the control of the nervous system 500ml water lost per day through skin (.5 gal)

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 itself against pathogens Most skin bacteria are associated with hair follicles and sweat glands Handwashing Most effective action to prevent spread of disease 20 seconds for washing hands 2-4 minutes for infectious material

Aging Becomes more fragile and dry Loss of elasticity Less effective body temperature control Melanocytes decrease

Disorders 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 Skin Eczema Impetigo Psoriasis Acute or chronic, noncontagious inflammatory skin disease Impetigo Acute, inflammatory, and contagious skin disease caused by staph Psoriasis Chronic inflammatory skin disease (reddish patches covered by silvery-white scales)

Disorders 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 Skin Rosacea Herpes Common inflammatory disorder (chronic redness and irritation to the face) Herpes Viral infection which is usually seen as a blister

Disorders Skin Genital herpes Shingle (herpes zoster) Virus which may appear as a blister in the genital area Shingle (herpes zoster) Skin eruption due to a virus infection of the nerve ending

Disorders Hair and Nails Head lice Parasitic insects Ingrown nails Common nail problem

Disorders 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 Body divided into 11 area; each part is 9% First degree burns Second degree burns Third degree burns

Skin Lesions Pressure ulcer (decubitus ulcers) Stage I Stage II Stage III Stage IV