Chapter 4 TISSUES

• Glands


  Epithelial tissues that produce secretions
• Types of glands


  • Unicellular (one-celled) glands
  • Multicellular (many-celled) glands
• Unicellular glands


  • Goblet cells secrete mucus in the respiratory and digestive tracts
• Multicellular glands


  • Exocrine glands have ducts that carry secretions to the oral cavity (e.g. salivary glands)
  • Endocrine glands secrete hormones directly into capillaries (e.g. thyroid gland)
• Types of Epithelial Tissue

  • Simple Squamous
  • Stratified Squamous
  • Transitional
  • Simple Cuboidal
  • Simple Columnar
  • Ciliated
• Simple Squamous sites


  • Alveoli and capillaries
• Stratified Squamous


  • Epidermis, lining of mouth, esophagus, and vagina
• Transitional site:


  • Urinary bladder
• Simple Cuboidal sites:


  • Thyroid gland, salivary glands, kidney tubules
• Simple Columnar sites:


  • Stomach lining, small intestinal lining
• Ciliated sites


  • Trachea and fallopian tubes
• Connective Tissue


  • Has a non-living intercellular matrix
  • Specialized cells
  • Classified by the composition of the matrix
• Types of Connective Tissue

  • Blood
  • Areolar (loose)
  • Adipose
  • Fibrous
  • Elastic
  • Bone
  • Cartilage
• Areolar sites:


  • Below the dermis and below the epithelium of tracts that open to the environment
• Adipose sites:


  • Between skin and muscles, around the eyes and kidneys
• Fibrous sites


  • Tendons, ligaments, dermis of the skin, and fascia around muscles
• Elastic sites


  • Walls of large arteries, around alveoli
• Bone sites


  • Bones of the skeleton
• Cartilage sites


  • Joint surfaces of bones, tip of nose and external ear, wall of trachea, discs between vertebrae
• Muscle Tissue


  • Specialized to contract and bring about movement
• Types of Muscle Tissue

  • Skeletal
  • Smooth
  • Cardiac
• Skeletal muscle


  Also called striated or voluntary muscle. Cells are cylindrical, have several nuclei, and have striations. Each cell has a motor nerve ending; nerve impulses are essential to cause contraction.
• Smooth muscle


  Also called visceral or involuntary muscle.
• Cardiac muscle


  Cells are branched, have one nucleus each, and have faint striations.
• Nerve Tissue


  • Neurons are specialized to generate and transmit impulses
• Cell body


  Contains the nucleus; axon carries impulses away from the cell body; dendrites carry impulses toward the cell body
• Synapse


  The space between two neurons; a neurotransmitter carries the impulse across a synapse
• Neuroglia


  Specialized cells in the CNS
• Schwann cells


  Specialized cells in the PNS
• Sites of nerve tissue: brain, spinal cord, and peripheral nerves (to provide sensation, movement, regulation of body functions, learning, and memory)
• Membranes


  Sheets of tissue on surfaces, or separating organs or lobes
• Types of Membranes


  • Epithelial membranes
  • Connective tissue membranes
• Epithelial Membranes


  • Serous membranes
  • Mucous membranes
• Serous Membranes


  • Thoracic cavity (pleura), pericardial sac, abdominal cavity (peritoneum)
• Mucous Membranes


  Line body tracts that open to the environment: respiratory, digestive, urinary, and reproductive. Mucus keeps the living epithelium wet; provides lubrication in the digestive tract; traps dust and bacteria in the respiratory tract.
• Connective Tissue Membranes


  • Peritoneum
  • Visceral pericardium
  • Parietal pleura
• Simple Squamous - one layer of flat cells; thin and smooth
• Simple Columnar - one layer of column-shaped cell
• Stratified Squamous - many layers of mostly flat cells; mitosis takes place in lowest layer
• Transitional - stratified, yet surface are rounded and flattened when stretched.