Chapter Six Flashcards
Organ (describe)
Two or more types of tissues grouped
together and performing specialized
functions
Integumentary System (describe)
The skin and its accessory structures (hair, nails, glands, sensory receptors)
Skin (describe)
Contains 2 layers: epithelial tissue and overlying connective tissue
Outer layer is the epidermis; inner layer is the dermis
Skin
Epidermis (describe)
Outer layer
Stratified squamous epithelium
Basement membrane between epidermis and dermis
Protects against water loss, chemicals, mechanical injury, pathogens
Skin
Dermis (describe)
Inner layer
Thicker of the 2 layers of the skin
Connective tissue
Contains collagenous & elastic fibers
Skin
Subcutaneous layer (hypodermis) (describe)
Beneath dermis; insulating layer
Areolar and adipose connective tissue
Not considered part of the skin
Contains blood vessels that supply skin
Keratinization (describe)
Process of hardening, dehydration, and keratin accumulation that occurs in epidermal cells as they migrate outward
Keratin (describe):
Tough, fibrous, waterproof protein made and stored in the cells
As cells reach outer surface, become tightly packed, develop desmosomes, form outer layer, stratum corneum
Stratum corneum cells are eventually shed from skin surface
Stratum Basale
Deepest layer of the epidermis, nourished by blood vessels in dermis
Melanocytes (describe)
Located in the stratum basale produce the dark pigment melanin
Absorbs UV light from sunlight and provides skin color
Factors Affecting Skin Color
Hereditary Factors
Environmental Factors
Physiological Factors
Dermis (describe)
Inner layer of skin; average of 1-2 mm thick
Contains dermal papillae to bind epidermis to underlying tissues
Connective tissue layer; contains muscle fibers
Nerve cell processes
Layers of Dermis
Papillary layer
Reticular layer
Layers of Dermis
Papillary Layer (describe)
Superficial layer; thinner of the 2 layers
Areolar connective tissue
Location of dermal papillae
Layers of Dermis
Reticular Layer (describe)
Deeper layer; thicker of 2 layers
Dense irregular connective tissue
Accessory Structures of the Skin (list)
Hair follicles
Nails
Skin glands (sweat and sebaceous)
Nails (describe)
Protective coverings on ends of fingers and toes
Parts of Nail (list)
Nail plate
Nail bed
Lunula
Nail Plate (describe)
Overlies nail bed