Integumentary System

epidermis

made up of epithelial tissue; composed of keratinized stratified squamous epithelium; avascular

dermis

made up of connective tissue

epidermal derivatives

hair follicles, hair, oil glands, sweat glands

thick skin

5-layer epidermis; found on palms of the hands and soles of the feet; does not contain hair follicles

thin skin

4-layer epidermis; everywhere but the palms of the hands and soles of the feet

cells of the epidermis

keratinocytes, melanocytes, merkle cells, langerhans cells

layers of the epidermis

stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, stratum corneum (before signing, get legal counsel)

layers of the dermis

papillary layer (loose connective tissue, superficial), reticular layer (dense irregular connective tissue, deep)

hypodermis

deep to the dermis; also called subcutaneous layer or superficial fascia; consists of white adipose tissue; well vascularized

sensory receptors in the skin

merkle cells, meissner’s copuscles, pacinian (lamellated) corpuscles

merkle cells

in epidermis; light touch and objects texture

meissner’s corpuscles

in dermis; found in the dermal papillae (papillary layer of the dermis); light touch

pacinian (lamellated) corpuscles

in dermis; found in reticular layer of dermis and hypodermis; coarse touch

eccrine sweat glands

widely distributed in skin (most numerous in foot soles); merocrine secretion

apocrine sweat glands

mainly in axillary and perineal regions (usually secrete into hair follicles); development depends on sex hormones and not functional until puberty; bacterial activity leads to body odor