ANATOMY & PHYSIOLOGY INTEGUMENTARY SYSTEM PART 2 Appendages of the Skin

Skin Appendages Glands  all arise from stratum basale then extend into dermis & subcutaneous layers  all exocrine glands  Release product thru a duct onto surface of skin Hair & Hair Follicles Nails

Cutaneous Glands 1. Sebaceous (Oil) Glands 2. Sweat Glands

Sebaceous Glands All over body except soles & palms most ducts empty onto hair follicle, rest empty directly onto skin

Sebaceous Glands Secrete Sebum Sebum:  Oily substances + fragmented cells  Become more active in puberty (androgen effect)  Function:  keeps skin soft & moist,  prevent hair from becoming brittle  kills bacteria

Sebaceous Gland If duct becomes blocked  whitehead forms With time oxidizes  blackhead forms If becomes infected  pimple

Seborrhea (Cradle Cap) Seen in newborns & infants Due to overactivity of sebaceous glands Starts as pink, raised lesions  form yellow to brown crust  sloughs off as oily dandruff

Sudoriferous Glands aka sweat glands 1 body has > 2.5 million 2 Types: 1. Eccrine glands 2. Apocrine glands

Eccrine Sweat Glands more of these than apocrine sweat glands Product: Sweat Sweat is made up of:  Water  NaCl  Vitamin C  Urea & uric acid  Lactic acid

Eccrine Glands Important part of thermoregulation function of skin Nerve endings send action potential when body temperature or external temperrature > normal When water in sweat evaporates body cools due to high heat of vaporization of water

Apocrine Sweat Glands In axilla and genital areas Usually larger than eccrine glands Ducts empty into hair follicles Begin to function during puberty If infectedwith bacteria  odor Product:  Fatty acids  Proteins  + what is in eccrine sweat

Hair Follicles Scattered all over body except palms & soles Functions:  Protection  Insulation

Hair Follicles

Nails

Homeostatic Imbalances Skin is largest organ so see many skin conditions Most common ailments fall into categories 1. Infections 2. Allergies 3. Skin cancer 4. Burns

INTEGUMENTARY SYSTEM PART 3 Homeostatic Imbalances of the Skin

Bacterial Infections Boils & Carbuncles  Infected sebaceous glands (especially neck)  Staphylococcus areus

Impetigo See blister-like pink lesions around nose, mouth  yellow crusty Elementary school age Extremely contagious staph

Athlete’s Foot Itchy, red, peeling Usually starts between toes Tinea pedis

Cold Sores(Fever Blisters) Herpes simplex Red, blisters, sore Virus remains dormant in cutaneous nerve Herpes is Forever

Contact Dermatitis Itching, redness, swelling Skin reacting to metal, chemical (in food, poison ivy)

Psoriasis Chronic condition Scaly, red to silvery scales Frequently starts on elbow, knee, scalp: can spread Treatment: cortisone cream

Burns Tissue damage & cell death caused by intense heat, cold, electricity, UV radiation, acids Rule of Nines:

1 st Degree Burns Only epidermis is damaged Heals after 2-3days discomfort Example: sunburn

2 nd Degree Burn Epidermis & upper dermis damaged Red, blisters, painful Regeneration possible With 1 st degree burns :  Partial thickness burns

3 rd degree burns Full thickness burn: damage to all layers of skin Not painful (nerve endings destroyed) Regeneration not possible Skin grafting

Skin Cancer Fastest rising cancer in young adults 3 kinds: 1. Basal Cell Carcinoma 2. Squamous Cell Carcinoma 3. Malignant Melanoma 4. Metastasis to Skin

Basal Cell Starts in stratum basale Slow, rare to metastasize Very common in sun-exposed areas #1 cause:sun exposure

Squamous Cell Carcinoma Stratum spinosum Less common, more likely to metastasize Sun exposed areas

Malignant Melanoma 5 % of skin cancer but the deadliest Risks  Family history  Changing mole  History of severe sunburns, tanning bed use Treatment: surgery, chemotherapy

Malignant Melanoma

ABCD Rule A: asymmetry, pigmentation not uniform B: border irregularity C: colors vary in same spot D: diameter > end of pencil eraser

Tattoos Needle injects ink into derrmis Pigment can migrate, safety not well established Needle infections not uncommon  Hepatitis C  liver cancer LASER to remove

Development of the Skin Lanuga: soft, fine hairs that develop in 5 th -6 th month of pregnancy Vernix caseosa: creamy, thick, white substance produced by sebaceous glands in 2 nd half pregnancy  Keeps skin soft, moist

Development of the Skin Milia:small white spots frequently seen on newborn – 3 rd week after birth Accumulations in sebaceous glands

Skin Changes with Aging Subcutaneous tissues decrease leading to: 1. Intolerance to cold 2. Skin drier due to decreased oil production & less collagen fibers 3. More likely to bruise 4. Decreased elasticity (baggy skin)