tissue

• What is the definition of tissue?


  A group of closely associated cells that perform related functions and are similar in structure
• What are the four basic types of tissue?

  Epithelium, connective tissue, muscle tissue, nervous tissue
• What is the study of tissues called?

  Histology
• What are the functions of epithelial tissue?


  • Physical protection
  • Absorption
  • Sensory reception
  • Ion transport
  • Secretion
  • Filtration
  • Formation of slippery surfaces for movement
• What are the special characteristics of epithelia?


  Cellularity, specialized contacts, polarity, support by connective tissue, avascular but innervated, regeneration
• How is epithelium classified according to thickness?


  As "simple" for one cell layer and "stratified" for more than one layer
• What are the shapes of epithelial cells used for classification?


  Squamous, cuboidal, columnar
• What is the characteristic of simple squamous epithelium?


  Cells are very thin and much wider than they are thick
• Where can simple squamous epithelium be found?


  Air sacs of the respiratory system, lining of blood vessels, heart, and lymphatic tubes
• Where can stratified squamous epithelium be found?


  Skin, vagina, esophagus, mouth
• What is the function of cuboidal epithelium?


  Secretion and absorption
• Where can cuboidal epithelium be found?


  Kidney tubules, ducts and small glands, surface of the ovary
• What is the characteristic of columnar epithelium?


  Elongated cells that are much longer than they are wide
• Where can simple columnar epithelium be found?


  Digestive tract, gallbladder, excretory ducts of some glands
• What is the function of microvilli in simple columnar epithelium?


  To increase surface area for absorption
• Where can pseudostratified ciliated columnar epithelium be found?


  Bronchi, trachea, uterine tubes, some of the uterus
• What are the characteristics of connective tissue?


  • Cells widely separated in a matrix
  • Originates from embryonic tissue called mesenchyme
  • Most diverse and abundant type of tissue
  • Functions: protect, support, bind together other tissues
• What are the types of connective tissue?


  Connective tissue proper, cartilage, bone, blood
• What are the basic functions of connective tissue?


  Support and binding of other tissues, holding body fluids, defending against infection, storing nutrients as fat
• What are the three major functions of the nervous system?


  Sensory, integration, motor
• What is the role of neurons in the nervous system?


  For processing, transfer, and storage of information
• What are the two types of neural cells in the nervous system?

  Neurons and neuroglia
• What is the function of neuroglia?


  Support, regulation, and protection of neurons
• What are the classifications of neurons based on information transmission?


  Sensory (afferent), motor (efferent), association (interneurons)
• What is the role of sensory neurons?


  Transmit sensory information from receptors of PNS towards the CNS
• What is the role of motor neurons?


  Transmit motor information from the CNS to effectors
• What is the role of association neurons?


  Transmit information between neurons within the CNS
• What are the two ways of tissue repair?

  • Regeneration
  • Fibrosis and scarring
• What is a tissue membrane?


  A thin layer or sheet of cells that covers the outside of the body, organs, and internal passageways
• What are the two basic types of tissue membranes?

  Connective tissue membrane and epithelial membrane
• What is the function of connective tissue membranes?


  To encapsulate organs and line movable joints
• What is the role of synovial membranes?


  To line the cavity of a freely movable joint
• What is the function of hyaluronan in synovial membranes?


  To trap water and form synovial fluid for lubrication
• What is the composition of epithelial membranes?


  Epithelium attached to a layer of connective tissue
• What is the function of mucous membranes?


  To line body cavities and hollow passageways that open to the external environment
• What is the role of lamina propria in mucous membranes?


  To support the fragile epithelial layer