Integumentary System Flashcards
Define Integumentary System
Hair, skin, nails. Divided into epidermis and dermis. Fx:protect, excrete, maintain internal temp., melanin production, H20-resistant, Vit D synthesis, Sensation
Epidermis Purpose
skin, protect, h20 resistant, Vit d absorption, melanin production, carotene accumulate -aid in eye fx
Living Skin Cells
Living keratinocytes found in stratum basal, stratum spinosum.
Cells in deep layers of epidermis
Stratum Basale-basal cells, merkel cells, melanocytes.
Stratum Spinosum-keratinocytes, langerhans cells
Skin Peeling Causes
Keratinohyaline- causes cell dehydration, interlocking of keratin fibers. Cells connected by desmosomes
Dermis vs. Epidermis
Epidermis-non-vascularized, keratinized stratified squamous epithelium. 4 cells types, 4-5 skin layers.
Dermis-strong, flexible. Dense irregular connective tissue btwn epidermis and areolar tissue, hypodermis (mostly collagen fibers). Like body stocking, hold glands, hair follicles, vascularized,
Integumentary System Layers
Epidermis: Stratum -basal, -spinosum, -granulosum, -lucidum (thick skin), -corneum.
Dermis: Papillary Layer, Reticular Layer.
Subcutaneous: no specific layers.
Epidermis Cells
Basal cells: keratinocyte stem cells
Merkel (tactile cells): sensory touch receptor, disc-like.
Melanocyte: pigment-producing cell. Pigment surround keratinocyte. Increase in response to UV rays
Keratinocyte: most abundant epidermis cell. Rise through layers.
Langerhans Cells (dendritic cells): branched cells acting as macrophages, present antigens to T cells.
Skin Color Variations
Pigments Carotene (aid in eye fx) and melanin (produced in basal, packaged in melanosome, transferred to keratinocytes. . Pigment can go up to spinosum or granulosum. More active in UV rays.
Excess Sun Exposure
melanin protects skin from UV rays. Freckles can occur, skin cancer-damage to basal cell DNA or melanocytes.
Papillary Layer
Epidermal ridges. Areolar tissue w/ capillaries. Supply nutrients to epidermis layers
Reticular Layer
Dense irregular connective tissue w/ collagen, elastic fibers. Btwn papillary & subcutaneous layers. Strengthen and provide elasticity.
Temp. control in body
Vasodilate to increase blood flow, bring heat closer to skin surface.
Vasoconstrict to decrease blood flow, bring heat to central core
Fight vs. flight: stress-induced, body shunt blood from dermis to heart, brain, muscles for combat. Cold skin, stress sweating.
Dermis fibers
collagen-give strength/flexibility.
elastin: skin resilience, reduce with age.
Cleavage lines: collagen & elastin fibers bundled in dermis;
Hair structure
extend into dermis and hypodermis;
3 zones-hair, root, shaft.
Hair root plexus: sense hair moving-nerve fiber wrapped around hair root.
Arrector pili: attached to follicle to force into upright position-warmth and defense. goose bumps
Hair root: anchors hair to skin at base of hair, extend halfway to skin surface.
Hair Shaft: extend from hair root to skin surface. contain keratinized cells w/ hard keratin-tougher than epithelial keratin.
Matrix: cells in hair where mitosis happens.
Fingernail structure
Nail body-visible nail.
Nail bed-epidermis area under skin.
Nail folds-epidermis folds surrounding nail body.
Hyponychium-the part junk gets under.
Nail root-matrix (actively growing part of nail)
Eponychium-cuticle.
Lunula-thickened nail matrix. covered by nail. White from obscured blood
Sweat Glands & Fx
Apocrine: pheromones. emotion and stress. Puberty
Merocrine: thermoregulation. excess body heat evaporates.
Sebaceous Glands
sebum-bactericide. oil/lipid.
Cerumen Glands
keep foreign particles/insects out of the ear. secrete ear wax
Ducts in Hair Follicles
Sebaceous not associated w/ hair follicle.
Apocrine: ducts empty into hair follicle.
Merocrine: open to sweat pore
