Integumentary System

Cards (114)

  • Also known as the "Intergument"

    The Skin
  • Cutaneous Layer

    The Intergurment
  • an epithelial layer of ectodermal origin
    Epidermis
  • a layer of mesodermal connective tissue
    dermis
  • the irregular junction between the dermis and epidermis, projections called
    dermal papillae
  • dermal papillae interdigitate with invaginating with this ridges to strengthen adhesion of the two layers.
    epidermal ridges
  • Epidermal derivatives
    hairs, nails, and sebaceous and sweat glands
  • a loose connective tissue layer usually containing pads of adipocytes.
    subcutaneous tissue or hypodermis
  • The specific functions of the skin fall into several broad categories.
    Protective, Sensory, Thermoregulatory, Metabolic, and Sexual signaling.
  • Protective
    It provides a physical barrier against thermal and mechanical insults, such as friction, and against most potential pathogens and other material.
  • Sensory
    Many types of sensory receptors allow skin to constantly monitor the environment, and various skin mechanoreceptors help regulate the body’s interactions with physical objects.
  • Thermoregulatory
    A constant body temperature is normally easily maintained; thanks to the skin’s insulat ing components (eg, the fatty layer and hair on the head) and its mechanisms for accelerating heat loss (sweat pro duction and a dense superficial microvasculature).
  • Metabolic
    Cells of skin synthesize vitamin D3 , needed in calcium metabolism and proper bone formation, through the local action of UV light on the vitamin’s precursor.
  • Sexual signaling
    Many features of skin, such as pigmentation and hair, are visual indicators of health involved in attraction between the sexes in all vertebrate species, including humans.
  • These ridges and the intervening sulci form distinctive patterns unique for each individual, appearing as combinations of loops, arches, and whorls - also known as fingerprints and footprints
    dermatoglyphs
  • The epidermis consists mainly of a stratified squamous kera tinized epithelium composed of cells called

    keratinocytes
  • There are also three much less abundant epidermal cell types
    pigment-producing melanocytes, antigen-presenting Lang erhans cells, and tactile epithelial cells called Merkel cells
  • thick skin

    found on the palms and soles
  • thin skin
    found elsewhere on the body
  • is a single layer of basophilic cuboidal or columnar cells on the basement membrane at the dermal-epidermal junction
    basal layer (stratum basale)
  • characterized by intense mitotic activity and contains, along with the deepest part of the next layer, progenitor cells for all the epidermal layers.
    stratum basale
  • intermediate filaments about 10 nm in diameter, An important feature of all keratinocytes in the stratum basale is the cytoskeletal

    keratins
  • are lymph-filled spaces created between the epidermis and dermis of thick skin by excessive rubbing, as with ill-fitting shoes or hard use of the hands.
    Frictions blisters
  • Friction blisters, If continued, such activity produces protective thickening and hardening of the outer cornified epidermal layers, seen as

    corns and calluses
  • is normally the thickest layer, especially in the epidermal ridges, and consists of generally polyhedral cells having central nuclei with nucleoli and cytoplasm actively synthesizing keratins.
    spinous layer (stratum spinosum)
  • Just above the basal layer, some cells may still divide and this combined zone is sometimes called the

    stratum germinativum
  • The keratin filaments assemble here into microscopically visible bundles called
    tonofibrils
  • consists of three to five layers of flattened cells, now undergoing the terminal differentiation
    granular layer (stratum granulosum)
  • a terminal differentiation process wherein, cytoplasm is filled with intensely basophilic masses.
    keratinization
  • name for the intensely basophilic masses in keratinization
    keratohyaline granules
  • found only in thick skin, consists of a thin, translucent layer of flattened eosinophilic keratinocytes held together by desmosomes
    stratum lucidum,
  • con sists of 15-20 layers of squamous, keratinized cells filled with birefringent filamentous keratins.
    stratum corneum
  • the cells that have lost nuclei and cytoplasm, consisting only of flattened, keratinized structures are called
    squames
  • a chronic skin condition wherein keratocytes are typically produced and differentiate at accelerated rates, causing at least slight thickening of the epidermal layers and increased keratinization and desquamation.
    psoriasis
  • The color of the skin is the result of several factors, the most important of which are the keratinocytes’ content of

    melanin and carotene
  • are brown or black pigments produced by the melanocyte
    Eumelanins
  • melanocyte
    a specialized cell of the epidermis found among the cells of the basal layer and in hair follicles.
  • The similar pigment found in red hair is called
    pheomelanin
  • The first step in melanin synthesis is catalyzed by a transmembrane enzyme in Golgi-derived vesicles called 

    tyrosinase
  • Tyrosinase activity converts tyrosine into
    3,4-dihydroxyphenylalanine (DOPA)