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Appendages of the Skin. Anatomy & Physiology Integumentary System Part 2. 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 .
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Appendages of the Skin Anatomy & Physiology Integumentary System Part 2
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 Sebaceous (Oil) Glands 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: Eccrine glands 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
Homeostatic Imbalances • Skin is largest organ so see many skin conditions • Most common ailments fall into categories • Infections • Allergies • Skin cancer • Burns
Homeostatic Imbalances of the Skin Integumentary System Part 3
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 Tineapedis
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:
1st Degree Burns Only epidermis is damaged Heals after 2-3days discomfort Example: sunburn
2nd Degree Burn • Epidermis & upper dermis damaged • Red, blisters, painful • Regeneration possible • With 1st degree burns : • Partial thickness burns
3rd 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: Basal Cell Carcinoma Squamous Cell Carcinoma Malignant Melanoma 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
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 5th -6th month of pregnancy • Vernixcaseosa: creamy, thick, white substance produced by sebaceous glands in 2nd half pregnancy • Keeps skin soft, moist
Development of the Skin Milia:small white spots frequently seen on newborn – 3rd week after birth Accumulations in sebaceous glands
Skin Changes with Aging • Subcutaneous tissues decrease leading to: • Intolerance to cold • Skin drier due to decreased oil production & less collagen fibers • More likely to bruise • Decreased elasticity (baggy skin)