Ch 5 Integumentary System Flashcards
(42 cards)
What are the two components of the cutaneous membrane?
Epidermis (superficial epithelium) and Dermis (deep connective tissue).
What are the accessory structures of the integumentary system?
Hair, hair follicles, nails, and exocrine glands.
What is the subcutaneous layer also called, and what does it do?
Hypodermis; separates the skin from underlying organs.
List five functions of the integument.
Protection, excretion, temperature regulation, melanin & keratin production, and vitamin D3 synthesis.
What type of epithelium composes the epidermis?
Stratified squamous epithelium.
What is the main cell type in the epidermis and what protein do they produce?
Keratinocytes; produce keratin.
How many layers does thin skin have vs. thick skin?
Thin skin has 4 layers; thick skin has 5.
List the 5 strata of the epidermis (deep to superficial).
Stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, stratum corneum.
What is the stratum basale attached to, and what does it contain?
Attached to basement membrane; contains basal cells, Merkel cells, and melanocytes.
What do Merkel cells do?
Act as sensory receptors for touch (form tactile discs).
What is the role of melanocytes?
Produce melanin to protect against UV radiation.
What do dendritic (Langerhans) cells do?
Immune defense against microbes and cancer.
What happens in the stratum granulosum?
Cells stop dividing, fill with keratin and keratohyalin, dehydrate, die.
What is the stratum lucidum?
A clear layer of dead keratinocytes found only in thick skin.
How long does it take new cells to reach the stratum corneum, and how long until they’re shed?
7–10 days to reach the top; shed after 2 weeks.
What is insensible perspiration?
Water loss through diffusion and evaporation from the skin.
What are the two layers of the dermis?
Papillary layer and reticular layer.
What tissue type is found in the papillary layer?
Areolar connective tissue.
What tissue type is found in the reticular layer?
Dense irregular connective tissue.
What gives skin its strength and flexibility?
Collagen and elastic fibers, and water content (turgor).
What are tension lines and why are they important?
Patterns of fiber bundles; cuts parallel to them heal better.
What type of tissue primarily makes up the hypodermis?
Adipose tissue.
What are its functions?
Energy storage, insulation, cushioning, blood reservoir.
What pigments affect skin color?
Carotene and melanin.
