HUMAN TISSUE (5)

• Tissue


  Groups of cells that perform the same general function
• Basic types of human tissue

  • Epithelial
  • Connective
  • Muscle
  • Nervous
• Epithelial tissue


  • Lines our body cavities and organs
  • Covers and protects the body
  • Organizes our body, creating order for it to function
• Epithelium


  A continuous cellular sheet that covers the body's surface, lines body cavities, and forms certain glands
• Types of epithelial cells

  • Stereociliated
  • Ciliated
• Microvilli


  Tiny, hair-like structures on the surface of some epithelial cells
• Cilia


  Fine, hair-like protuberances on some epithelial cells that move fluid and particles through the cavity of an organ
• Endothelium


  Epithelial tissue with a single layer of squamous cells attached to a basement membrane, lining the heart, lymphatic vessels, and blood vessels
• Types of epithelial tissue classified by number of cell layers

  • Simple (one-layered)
  • Stratified (multilayered)
  • Pseudostratified (one-layered but appearing multilayered)
• Types of epithelial tissue classified by cell shape

  • Squamous (flat surface cells)
  • Columnar (tall, cylindrical surface cells)
  • Cuboidal (cube-shaped surface cells)
• Glandular epithelium


  A special type of epithelium that forms our glands and secretes hormones and other substances
• Types of glands


  • Endocrine (secrete into the blood or lymph)
  • Exocrine (secrete into ducts that lead to external or internal surfaces)
  • Mixed (contain both endocrine and exocrine cells)
• Connective tissue


  • Binds together and supports body structures
  • Classified as loose or dense
• Loose (areolar) connective tissue

  Has large spaces that separate the fibers and cells, contains a lot of intercellular fluid
• Types of dense connective tissue

  • Dense regular (tightly packed fibers in consistent pattern)
  • Dense irregular (tightly packed fibers in inconsistent pattern)
• Adipose tissue


  • A specialized type of loose connective tissue where a single lipid (fat) droplet occupies most of each cell
  • Acts as insulation, cushion, and energy storage
• Types of muscle tissue

  • Striated (voluntary)
  • Cardiac (involuntary, striated)
  • Smooth (involuntary)
• Nervous tissue


  The communication system of the body, responsible for sensing the environment, reacting, and coordinating everything
• Neurons


  Highly specialized cells that generate and conduct nerve impulses
• Neuroglia


  Support cells that insulate and protect neurons in the central nervous system
• four basic types human tissues

  epithelial

  connective

  muscle

  nervous