Aging and Diseases
Disease = failure of homeostasis
Symptoms = not verifiable
Signs = verifiable
Inflammation = (histamine) = pain, redness, swelling, warmth, loss of function
Regeneration restores homeostasis
Fibrosis = scar tissue (lack of homeostasis)
Aging (epidermis THINS)
More injury and infection
Less Vitamin D production
Increased sun sensitivity
Hair & skin color changes; hair thins
Skin dry & scaly - less sebum (sebaceous glands)
Less thermoregulation
Wrinkles & saggy skin
Skin Cancer (most common cancer)
Basal cell carcinoma - most common – begins in stratum basale; most treatable
Squamous cell carcinoma – begins in most superficial layers; very treatable
Malignant melanoma - least common; begins in melanocytes; metastasizes; most deadly
ABCD Rule (asymmetry ,border, color, diameter)
Acne - affects sebaceous glands
Blackheads - blocked pore is open to air
Whiteheads - blocked pore; pore is closed
Pustules - red and inflamed; often bacterial
Psoriasis (rapid mitosis = scaly patches)
Eczema (less sebum = moisture loss)
Additional diseases
Vitiligo - loss of skin color in blotches; melanocytes die or stop functioning
Tinea Pedis (athlete’s foot) - fungal infection; contagious
Common warts (HPV) - skin growth caused by virus; contagious
Hives (urticaria) - skin rash triggered by allergic response; itchy raised welts
Herpes zoster (shingles) - same virus that causes chicken pox; vaccine can prevent
Rosacea - visible blood vessels on face
Birthmarks - irregularity on skin (i.e., hemangioma)
Albinism - little to no melanin produced
Impetigo - common skin infection in children
Ingrown nail - side of nail grows into skin
Thrush - fungal infection in mouth
Ingrown hair - hair grows back into skin
Herpes (HSV-1) - blistering sores
Stretch marks - elastin fibers in dermis tear