Tissues

• The 4 types of tissues in the body are epithelial, connective, muscle, and nervous tissue.
• Epithelial tissue covers the body and lines inside of organs.
• Connective tissue supports.
• Muscle tissues move the body.
• Nervous tissue controls the body.
• Describe the characteristics of epithelium.

  • Avascular - no blood vessels
  • Highly regenerative
  • Very little extracellular matrix
• The functions of the epithelia are to sense, protect, absorb, secrete, and transport.
• Epithelial tissue can be classified by two characteristics, the number of layers and shape of the cells.

  Number = simple or stratified

  Shape = squamous, cuboidal, columnar, or transitional
• Simple squamous if found in the glomeruli and lining of things like blood vessels.
• Simple cuboidal is found in lining of kidney tubules.
• Simple columnar is found in lining of gastrointestinal and respiratory tracts.
• Pseudostratified columnar has cilia and is found in upper respiratory tract.
• Stratified squamous is found in the esophagus lining and epidermis.
• Stratified cuboidal is found in ducts of sweat glands.
• Stratified columnar if found in lining of male urethra.
• Transitional is found in lining of urinary bladder.
• Connective tissue characteristics:

  1. Extracellular matrix made of fibers and ground substance
  2. All comes from common origin known as mesenchyme
• Connective tissue functions to:

  • fill spaces
  • store fat
  • produce blood cells
• The types of connective tissue are:

  • Loose connective tissue
  • Dense connective tissue
  • Cartilage
  • Bone
  • Blood
• The three types of loose connective tissue are:

  1. Areolar
  2. Reticular
  3. Adipose
• Areolar tissue has a large amount of ground substance and is found in subcutaneous tissue.
• Reticular tissue has large amount of ground substance and is found in the spleen, thymus, and bone marrow.
• Adipose tissue is fat tissue that stores energy and is found in the body.
• The three types of dense tissue are:

  1. Dense regular
  2. Dense Irregular
  3. Elastic
• Dense regular tissue is strong in one plane, and makes up tendons and ligaments.
• Dense irregular is strong in all planes and makes up the skin and capsules around organs.
• The three types of cartilage are hyaline, elastic, and fibrocartilage.
• Hyaline cartilage is avascular, sit in cavities called lacunae, and is found in the tip of the nose, trachea, and bronchi.
• Elastic cartilage is a strong and stretchy supporting connective tissue, and found in the external ear and epiglottis.
• Fibrocartilage is the strongest cartilage type and is found in the intervertebral discs and knee joint.
• There are three types of muscle tissue, skeletal, cardiac, and smooth.
• There are four types of membranes, the mucous, serous, synovial, and cutaneous.

  The mucous membranes line body cavities that are open to the outside of body.

  The serous membranes line the closed body cavities and the organ within them.
• The synovial membrane lines the joint cavities and freely-moveable joints.

  The cutaneous membrane is your skin.
• Elastic tissue is a strong and flexible dense connective tissue, and is found in the aorta.