Define These Skin Anatomy Terms Flashcards

organ system a group of interacting organs forming a whole skin membranous tissue forming the external covering of a human and the epidermis and dermis dermatology the branch of medicine that is concerned with the physiology and pathology of the skin excretion the physiological processes of discharging waste subcutaneous located beneath skin, usually within the dermis hypodermis the layer of loose connective tissue containing fat cells below the dermis in many regions of the body elasticity flexibility superficial fascia sheet of irregular dense fibrous connective tissue separating the dermis from its muscles, tendons, ligaments, or bones. vitamin D fat-soluble vitamin; produced in skin by ultraviolent irradiation of sterols found in milk epidermal derivative any specialized structure of the epidermis including hair and hair follicles, nails, sweat glands and sebaceous glands epidermal ridges unique patterns of epidermis which are located on the palms of the hands and soles of feet -fingerprints thermoregulation maintenance of internal body temperature primary germ layers first three tissue types to differentiate in an early stage of embryonic development, ectoderm, mesoderm, endoderm ectoderm the outermost layer of an embryo mesoderm the middle layer of the embryo, lying between the ectoderm and the endoderm endoderm the innermost layer of an animal embryo epidermis the outer, protective layer of stratified squamous epithelium covering the dermis keratinization process of converting (hair, nails, horns..) into keratin keratohyaline the protein precursor to keratin which is the form of the protein in the stratum granulosum of the epidermis keratin a tough, protein; helps protect the epidermis from abrasion and water loss keratinocytes vast majority of cells comprising of stratified squamous epithelium of the epidermis melanocytes small set of spider-shaped epidermal cells int he stratum germinativum (10-25% of the basale cells) epidermal dendritic cell=Langerhans' cells a star-shaped macrophage derived from the bone marrow Merkel cell an exteroreceptor located in the stratum germinativum of the epidermis; a small receptor stratum basale=stratum germinativum the basal layer of the stratified squamous epithelium of the epidermis, the youngest cells which are undergoing mitosis stratum spinosum the second layer (from the bottom) of the stratified squamous epithelium of the epidermis, consists of prickle cells stratum granulosum the third deepest layer(from the bottom) of the stratified squamous epithelium of the epidermis; flattened spindle-shaped keratinocytes stratum lucidum the fourth deepest layer(from the bottom) of the stratified squamous epithelium of the epidermis, only appears in the thick skin of the palms of the hands and soles of the feet stratum corneum the outer protective layer ("horny layer") of the stratified squamous epithelium of the epidermis, 20 or 30 cell layers thick; dead cells pili=hairs an epidermal derivative produced by the hair follicle in the dermis of the skin medulla tthe interior of the hair shaft cortex the exterior of the hair shaft hair follicle the tubular infolding of the epidermis containing the root of the hair bulb of the hair the lower expanded section of the root of a hair which fits like a cap over the hair papilla papilla of the hair the small nipplelike projection or protuberance of areolar connective tissue at the base of the bulb portion of the root of a hair which brings the capillary blood supply closer to the epidermal cells involved in the synthesis of the growing hair shaft. arrector pili short smooth muscle that extends from the side of a hair follicle on which the sebaceous gland is located to the basement membrane of the nearby epidermis root hair plexus complex network of sensory nerve endings nails an epidermal derivative produced at the dorsal surface of the fingers and toes dermis the dense irregular fibrous connective tissue layer of the skin located below the epidermis, containing nerve endings, hair follicles, sweat and sebaceous glands, and blood vessels papillary region 20% of the dermis, consists areolar connective tissue dermal papillae series of bulges of the papillary region of the dermis of the skin recticular region 80% of the dermis, consists of dense irregular connective tissue corpuscles of touch group of sensory receptors in the dermis, which respond to pressure or vibrations tactile corpuscle=Meisner's corpuscle in the dermal papillae; a small receptor surrounded by Schwann cells lamellated corpuscle=Pacinian corpuscle receptor scattered deep in the dermis; vibration