Integumentary System

 The skin is the largest organ of the body covering 3,000 square inches of surface area and 15% of total body weight!!!  There are 3 main layers to our skin:  EPIDERMIS  DERMIS  HYPODERMIS OR SUBCUTANEOUS FASCIA

EPIDERMIS

 The skin has 3 layers and the Epidermis has 2 main layers of it’s own  The outer most layer is the stratum corneum  These cells are constantly shed and replace by new cells

EPIDERMIS  The innermost layer of the epidermis is the stratum germinativum  New skin cells are made here

DERMIS  This layer is known as the true skin or corium  Characteristics of this layer:  Framework of elastic connective tissue  Contains lymph and blood vessels  Contains nerves, involuntary muscle, sweat and oil glands, and hair follicles  Covered with papillae  Is ridged--fingerprints

DERMIS

HYPODERMIS  Also known as the subcutaneous fascia  Innermost layer  Made of elastic AND fibrous connective tissue AND adipose tissue  Connects skin to underlying muscle

HYPODERMIS  Also: Perspiration helps the body cool down  How? Excess water on the surface of the skin is evaporated ( a natural cooling process)  Second type of gland: Sebaceous gland Oil glands that open into hair follicles Produce sebum which keeps hair and skin becoming too dry Sebum has natural antibacterial/antifungal properties due to its acidity Blackhead or pimples are formed when these glands become plugged with dirt or oil

HYPODERMIS

Glands of the skin  The integumentary system has 2 main types of glands  Sudoriferous glands  These are the sweat glands: coiled tubes that start from the dermis up to the surface of the skin to the pores  What causes sweat to smell?  Sweat + bacteria on the skin=BODY ODOR

Hair and Nails  Hair and nails are also part of the integumentary system  Alopecia: permanent loss of hair on the scalp (baldness)  Nails: made of dead, keratinized epidermal epithelial cells which are packed closely making a dense thick surface (your fingernails an toenails)  Formed in the nail bed

What does the integumentary system do?  It provides protection: 1. Protects us from the sun’s harmul rays 2. Intact skin protects us from pathogens 3. Holds in moisture so we don’t dry out

Skin functions  Sensory Perception: helps body respond to pain, pressure, temperature, and touch  Body temperature regulation: Dilated blood vessels=heat escapes through skin Constricted blood vessels=heat retained in the body

Skin functions  Storage: can temporarily store glucose, water, vitamins, and salts  Fatty tissue is a source of energy  Absorption: can absorb some medications (transdermal) 1. Nicotine patch 2. Motion sickness patch 3. Heart disease medication (blood pressure) 4. Birth control

Skin functions  Excretion: skin aids body in elimination of salt, some wastes, excess water, and heat  Production: skin absorbs the sun ray, which aids in the production of Vitamin D

Pigmentation  Specialized cells in the epidermis produce melanocytes  Produce melanin—a brownish black pigment  We all have the same amount of melanocytes but it is the amount of melanin produced that makes us lighter or darker (this is inherited)

Pigmentation  Albino: absence of color pigments

Pigmentation  Other abnormal colors of the skin are: 1. Erythema=reddish color caused by burns, congestion of blood in vessels from infection or injury or disease 2. Jaundice=yellow discoloration of skin. Seen in newborns, diseases of liver or gallbladder 3. Cyanosis=bluish discoloration of skin caused by lack of O2. Can be caused by disease or poisoning

Skin Eruptions  Read pages 147 and 148 in 8 th edition and know a the description and picture of each  Macules  Papules  Vesicles  Pustules  Crusts  Wheals  Ulcers  cyst

Diseases/Abnormalities of skin  Acne Vulgaris=inflammation of the sebaceous glands  High occurrence in adolescence  Hormonal changes  Occurs with blockage of hair follicles (oil, dirt, cosmetics, bacteria)  Treatment: frequent and thorough skin washing  Avoiding creams and heavy makeup  Topical antibiotics, chemical peels, retinoids, oral contraceptives, laser and light therapy

 Athlete’s Foot:

 Athlete’s foot is a fungal infection  S/S: itching, cracking skin, blisters, open sores  Tx: topical and/or oral antifungal meds  Keep area clean and dry  Helpful Hints: Wear shower shoes when in public showers!!!!

 Skin Cancer: Most common type of cancer  3 main types of cancer 1. Basal cell=epidermis of the skin. Slow growing and usually does not spread. Lesions are usually pink-yellow white, depressed center 2. Squamous cell carcinoma=thin cells of epithelium. Can spread quickly. Lesions start small, firm, red, flat that later scale and become crusty Sores that do not heal

 Melanoma=develops in melanocytes, most dangerous type of skin cancer  Lesions are brown/black/pink/multicolored  Flat or raised slightly  Asymmetrical  Irregular borders  Can develop from moles or a nevus  Causes: sun exposure, tanning beds, chemicals, radiation  Tx: removal of lesion, cryotherapy, laser therapy  Surgical excision usually followed up with radiation or chemotherapy if metastasis

 Dermatitis=inflammation of the skin  S/S: redness, itching, dryness, edema, macular-papular rashes, scaling  Tx: eliminate the cause, anti-inflammatory ointments, antihistamines, steroids  Causes: allergic reactions to plants, animals, cosmetics, detergents, foods

 Eczema=inflammatory dermatitis caused by allergen or irritant, noncontagious  Other causes: diet, stress, makeup, soaps, medications  S/S: dryness, redness, edema, itching, crusting oozing vesicles, scaling  Tx: Removal of irritant, steroid creams

 Impetigo=highly contagious skin infection  Causes: streptococci or staphylococci  S/S: red lesions, which erupt and ooze then form yellow/brown crust  Usually affects infants and children  Tx: wash lesions with soap and water but may need topical antibiotics and oral antibiotics

 Psoriasis=noncontagious and chronic skin disease  Has periods of exacerbations (symptomatic) and remission (asymptomatic)  Unknown causes but may be hereditary  Exacerbations caused by stress, cold, pregnancy, alcohol, endocrine changes  S/S: thickened red areas  Covered with white or silver scales  Tx: cortisone, topical vitamin D, phototherapy

 Ringworm=fungal infection that is highly contagious  Flat raised circular area with healthy inner area, surrounded by itchy, scaly or crusty outer ring  Tx: antifungal meds, oral and/or topical

 Verrucae=warts  Caused by human papilloma virus  Can be genital, plantar, palmar  S/S: rough, hard, elevated rounded surface  May disappear spontaneously or need removal  Cryo, acid, chemicals, laser

Port wine stain Type of birthmark: Large reddish purple discoloration of the face or neck, will not resolve without treatment---laser tx—small areas at a time

Hemangioma Soft raised, reddish purple birthmark that is a benign tumor made up of newly formed blood vessels. Usually resolve, without tx by about age 5, but not always.

Hemangioma Large facial hemangioma

Pigmented Birthmark—excess skin pigment