Term | Definition |
INTEGUMENTARY SYSTEM | COMPOSED OF SKIN, HAIR, OIL AND SWEAT GLANDS, NAILS, AND SENSORY RECEPTORS. |
SKIN (CUTANEOUS MEMBRANE) | COVERS EXTERNAL SURFACE OF BODY; LARGEST ORGAN |
EPIDERMIS | SUPERFICIAL THIN LAYER OF SKIN; AVASCULAR EPITHELIAL TISSUE |
DERMIS | DEEP THICK LAYER OF SKIN; VASCULAR CONNECTIVE TISSUE (DENSE IRREGULAR CONNECTIVE TISSUE) |
SUBCUTANEOUS | NOT PART OF SKIN; CONSISTS OF AREOLAR AND ADIPOSE TISSUES (LOOSE CONNECTIVE TISSUES) |
TYPES--KERATINOCYTES | PRODUCE KERATIN; A TOUGH FIBROUS PROTEIN THAT HELPS PROTECT SKIN AND UNDERLYING TISSUES FROM ABRASIONS, HEAT, MICROBES AND CHEMICALS; ALSO WATER REPELLANT SEALANT (90%) |
TYPES--MELANOCYTES | PRODUCE PIGMENT MELANIN. CUBOIDAL. # OF MELANIN DETERMINES COLORATION (8%) |
MELANIN | PIGMENT THAT CONTRIBUTES TO SKIN COLOR AND ABSORBS DAMAGING UV LIGHT |
TYPES--LANGERHANS CELLS | IMMUNE RESPONSES AGAINST MICROBES |
TYPES--MERKEL CELLS | TACTILE; TOUCH SENSATION |
FUNCTIONS OF SKIN | Regulate body temp, store blood, protect body from external environ., detect cutaneous sensations, excrete and absorb, synth VitD |
THIN SKIN | FOUR LAYERS OF EPIDERMIS (STRATUM BASALE, SPINOSUM, GRANULOSUM, AND CORNEUM). HAS HAIR. |
THICK SKIN | FIVE LAYERS OF EPIDERMIS (STRATUM BASALE, SPINSOSUM, GRANULOSUM, LUCIDUM, CORNEUM). NO HAIR. |
STRATUM BASALE | DEEPEST LAYER OF EPIDERMIS; SINGLE ROW OF CUBOIDAL OR COLUMNAR KERATINOCYTES. KERATIN PROTECTS DEEPEST LAYER FROM INJURY |
STRATUM SPINOSUM | SUPERFICIAL TO STRATUM BASALE. CONTAINS NUMEROUS KERATINOCYTES. COARSER BUNDLES; MAKES IT STRONGER AND FLEXIBLE. (8-10 ROWS) |
STRATUM GRANULOSUM | KERATINOCYTES IN APOPTOSIS. INCLUDES KERATOHYALIN (A KERATIN PRECRUSOR). LIPID RICH REGION IS WATER REPELLANT (3-5 ROWS) |
STRATUM LUCIDUM | THICK SKIN AREAS. LAYERS OF DEAD KERATINOCYTES (4-6 ROWS) |
STRATUM CORNEUM | CORNEOCYTE PRESENCE (SQUAMES). NO NUCLEI. CORNIFIED LAYER. FRICTION-->CALLUS (25-30 ROWS) |