Chapter 10

• Integumentary system


  Consists of skin and its appendages, like gland, hair, fur, wool, feathers, scales, claws, beaks, horns, hooves, and nails. It functions for protection, thermoregulation, and sense reception.
• Epithelial tissue or epithelium


  Composes skin
• Cutane/o, derm/o, and dermat/o


  Skin
• -derma


  Skin
• Dermatology


  The study of skin
• Epidermis or avascular layer


  The outermost and most superficial layer of skin. It is several layers thick, does not have blood vessels, and depends on deeper layers for nourishment.
• Epi-


  Above
• Dermis


  Skin
• Stratified squamous epithelium


  Flat, plate like cells that make up the epidermis.
• Keratin


  Protein that provides skin its waterproofing properties. Found in dead skin cells.
• Kerat/o


  Keratin, horny, cornea
• Melanocytes


  Cells that produce black pigment. Found is the basal layer.
• Melanin


  Black pigment produced by melanocytes. It protects the skin from harmful sun rays and is responsible for skin pigment.
• Melan/o


  Black or dark
• Albinism


  The absence of normal pigmentation
• True albinism


  Absence of pigmentation in hair, skin and eyes
• Dermis or corium


  Layer directly deep of the epidermis. It is composed of blood and lymph vessels, nerve fibers, and the accessory organs of the skin. Contains sensory nerves for touch, temperature, pain, and pressure.
• Perception


  The ability to recognize sensory stimuli
• Tactile perception


  The ability to recognize touch sensation
• Fibroblasts


  Fiber producing cells. Found in the dermis. Produces collagen
• Collagen


  Tough, flexible, fibrous, protein found in skin, bone, cartilage, tendons and ligaments.
• -gen


  Produce
• Histiocytes or macrophages


  Phagocytic cells that engulf foreign substances. Found in the dermis
• Mast cells


  Cells that respond to insult by producing and releasing histamine and heparin. Found in the dermis
• Histamine


  A chemical released in response to allergens that causes itching.
• Heparin


  An anticoagulant chemical released in response to injury.
• Subcutaneous layer or hypodermis


  Located deep to the dermis and is composed of connective tissue. Contains a large amount of fat.
• Stratum basale or stratum germinativum


  Deepest or basal layer than continually multiplies to replenish cells lost from the epidermal surface. Made of cuboidal cells.
• Cuboidal cells


  Cubelike cells arranged in rows.
• Stratum spinosum, prickle, or spinous layer.


  The layer immediately superficial to the stratum basale, which is the thickest in hairless regions and in areas of wear and tear. Keratinization and desquamation begin in this layer.
• Keratinization


  The development of the hard protein constituent of hair, nails, epidermis, horny structures, and tooth enamel.
• Desquamation


  The process in which cell organelles gradually dissolve
• Stratum granulosum


  Layer immediately superficial to the stratum spinosum. Cells contain keratin granules in their cytoplasm.
• Stratum lucidum


  Layer immediately superficial to the stratum granulosum, which is clear because of the accumulation of keratin fibers in the cell cytoplasm. This layer is not present in all species, but when present, it is found in areas of high wear and tear.
• Stratum corneum or horny layer


  Most superficial layer of the epidermis, which consists of layers of dead, highly keratinized and flattened cells.
• Adipocytes


  Fat cells that produce lipids
• Adip/o


  Fat
• Sebaceous or oil glands


  Glands located in the dermis that secretes sebum. It lubricates the skin, helps slow bacterial growth, and can be used to mark territory.
• Sebum


  A slightly acidic substance released from sebaceous glands. It is released from ducts near hair follicles.
• Ducts


  Tube like passages