chapter 5 the integumentary system Flashcards
What are the three layers of skin?
Epidermis (outer shield), Dermis (middle cushion), Hypodermis (deep fatty layer).
What are the traits of the epidermis?
Protective, avascular (no blood flow), made of keratinized stratified squamous epithelium.
What are the main types of cells in the epidermis?
Keratinocytes (keratin factory), Melanocytes (melanin for skin color), Langerhans’ cells (immune warriors), Merkel cells (touch detectors).
What is the Stratum Corneum?
Top layer of the epidermis, consisting of 20-30 dead, flat cells that shield and waterproof.
What is the Stratum Lucidum?
Only found in thick skin (palms, soles), composed of clear, dead keratinocytes.
What occurs in the Stratum Granulosum?
Keratinization starts here; granules act as water-loss blockers.
What is the Stratum Spinosum?
Thick layer with web-like pre-keratin filaments and Langerhans’ cells.
What is the Stratum Basale?
Deepest layer of the epidermis, serves as stem cell headquarters; contains melanocytes and Merkel cells.
What are the two layers of the dermis?
Papillary (light touch and pain/temp) and Reticular (tough collagen and stretchy elastin).
What is the function of the hypodermis?
Acts as a fat cushion for shock absorption and insulation.
What are the main skin pigments?
Melanin (yellow to black), Carotene (orange), Hemoglobin (pink/red from blood flow).
What are the types of sweat glands?
Eccrine (watery sweat for cooling) and Apocrine (stinky sweat, starts at puberty).
What are specialized sweat glands?
Ceruminous (earwax) and Mammary (milk).
What do sebaceous glands produce?
Sebum (oil) for lubrication and bacteria-killing; absent on palms and soles.
What is hair made of?
Dead keratin; melanin determines color.
What are the types of hair?
Vellus (soft baby hair) and Terminal (thick hair on scalp, brows, pubes).
What are nails made of?
Hard keratin plates for protection.
What are the functions of the skin?
Protection (physical, chemical, immune), Temperature regulation (sweat + blood vessel dilation), Sensation (touch/pain detection).
What role does the skin play in Vitamin D production?
Skin acts as a sunlight lab for making this vital vitamin.
What are the types of skin cancer?
Basal cell carcinoma (common, least dangerous), Squamous cell carcinoma (middle-ground danger), Melanoma (rare, deadly).
What are the ABCDEs of melanoma?
Asymmetry, Border irregularity, Color variation, Diameter > 6mm, Elevation.
What are the degrees of burns?
1st degree (red, hurts - epidermis only), 2nd degree (blisters - epidermis + upper dermis), 3rd degree (full thickness, no pain).
What is the Rule of Nines?
Quick burn severity estimate; critical if 25% of body = 2nd degree, 10% = 3rd degree, or face/hands/feet = 3rd degree.
What changes occur in aging skin?
Skin becomes thin, dry, wrinkly, less elastic; higher cancer risk due to fewer melanocytes and immune cells.
