Major Tissue Types

Major Tissue Types

1. Muscular Tissue

   • Skeletal Muscle (Location: Skeletal muscles. Cell type: Skeletal muscle fibers)
   • Cardiac Muscle (Location: walls of the heart. Cell type: cardiac muscle cells)
   • Smooth Muscle (Location: intestinal walls. Cell type: smooth muscle cells)

2. Nervous Tissue (Location: the brain. Cell type: neurons)

3. Epithelial Tissue

   • Simple Squamous Epithelium (Location: Alveoli of lungs. Cell type: squamous epithelial cells)
   • Simple Cuboidal Epithelium (Location: kidney tubules. Cell type: cuboidal epithelial cells)
   • Simple Columnar Epithelium (Location: gallbladder. Cell type: columnar epithelial cells)
   • Ciliated Pseudostratified Columnar Epithelium (Location: trachea. Cell type: columnar epithelial cells)
   • Non-ciliated Pseudostratified Columnar Epithelium (Location: male urethra. Cell type: columnar epithelial cells)
   • Keratinized Stratified Squamous Epithelium (Location: epidermis. Cell type: squamous epithelial cells)
   • Non-Keratinized Stratified Squamous Epithelium (Location: esophagus. Cell type: squamous epithelial cells)
   • Stratified Cuboidal Epithelium (Location: sweat gland. Cell type: cuboidal epithelial cells)
   • Stratified Columnar Epithelium (Location: uterine gland. Cell type: columnar epithelial cells)
   • Transitional Epithelium (Location: urinary gland. Cell type: transitional epithelial cells)

4. Connective Tissue

   • Lymphocytes migrate through the body. Some can develop into plasma cells, which produce antibodies.
   • Fibrocytes: spindle shaped cells that maintain the connective tissue fibres of connective tissue proper
   • Adipocytes: contains a single, enormous lipid droplet
     • Connective tissue fibres
       • Collagen fibres: tendons and ligaments
       • Reticular fibres: resist forces applied from many directions as they form a network rather than share a common alignment
       • Elastic fibres: interconnect vertebrae.
     • Fluid connective tissue: groups of cells that float around in fluid matrix
       • Plasma (blood) contains blood cells and fragments of cells.
       • Lymph: forms as interstitial fluid enters lymphatic vessels
   • Microphages are phagocytic blood cells. Attracted to sites of infection.
   • Melanocytes: synthesise and store melanin.
   • Loose connective tissue:
     • Areolar tissue forms a layer that separates the skin from deeper structures
     • Adipose tissue provides padding, absorbs shocks, acts as an insulator to slow heat loss through the skin, and serves as a packing or filler around structures.
     • Reticular tissue supports functional cells of the liver and spleen
     • Dense Connective Tissue: collagenous. Collagen fibres are the dominant type
       • Tendons (regular tissue) are cords of dense regular connective tissue that attach skeletal muscles to bones.
       • Ligaments (irregular tissue) connect the bone to another or stabilize the position of internal organs
   • Fibroblasts: secrete hyaluronan and proteins
   • Mesenchymal cells: stem cells that provide defense.
   • Mast cells contain histamine and heparin. Histamine stimulates local inflammation. Heparin is an anticoagulant that enhances blood flow during inflammation.
   • Supporting connective tissue
     • Cartilage: firm gel that contains polysaccharide derivatives called chondroitin sulfates.
       • Hyaline: provides stiff & flexible support. Found in ribs, bones of sternum, supporting larynx, trachea, bronchi
         • Elastic: provides support but tolerates distortion without damage. Found in external ear, epiglottis, auditory canal
           • Fibrocartilage: resists compression, prevents bone-to-bone contact. Found within knee joint
     • Bone: develops from cartilage. Osteocyte = mature cell