Tissues and homeostasis

• Tissue


  Connects, supports and binds other tissues in body. Provides structure to the body

  
• Tissue


  • Covers body surfaces: Body cavities, skin, and organ surfaces
  • Moves the body and its parts, produce movement
  • Very complex, coordinating and controlling many body activities
• Tissue


  • Skeletal muscles
  • Epithelial cells covering the surface of the heart
• Connective tissue


  Has diverse structure and function, but all types have three similar components: specialized cells, ground substance, and protein fibers

  
• Ground substance


  • A clear, colorless, and viscous fluid that fills the space between the cells and the fibers
• Connective tissue fibers


  • Collagen
  • Reticular
  • Elastic

  
• Collagen fibers


  Composed of collagen protein which is the most abundant protein in the human body. Forming structures like tendons, organ capsules, ligaments, and even the dermis
• Elastic fibers


  Smaller than collagen fibers and form a sparse network in between collagen bundles in some tissues that are subject to regular stretching or bending. Have rubber-like properties that allow the fibers to be stretched and return to their original shape
• Reticular fibers


  Composed of collagen proteins arranged in bundles with an outer coating of glycoprotein, commonly found in the wall of blood vessels and forms a network around the cells in some tissues

  
• Fibroblasts


  • Large cells with irregular processes that secrete collagen, elastin

  
• Adipocytes (fat cells)


  • Convert glucose from blood into lipids
• Loose connective tissue


  Areolar tissue, reticular tissue, and adipose tissue. Has a more flexible and loose structure than dense connective tissue

  
• Dense connective tissue


  Fibers are closely packed and take up more space than ground substances and cells. The two different forms are dense irregular and dense regular

  
• Bones


  Hard, inelastic and a tough organ that forms part of the vertebral skeleton
• Cartilage


  Soft, elastic and flexible connective tissue that protects the bone from rubbing against each other, reduce friction
• Blood


  A fluid connective tissue. It consists of formed elements and plasma, and is located in blood vessels. Transports nutrients and oxygen, removes carbon dioxide and other wastes, distributes heat and plays a role in fluid, ion, and pH balance
• Interstitial fluid


  Fluid found in the spaces around cells. Comes from substances that leak out of blood capillaries. Helps bring oxygen and nutrients to cells and to remove waste products from them
• White blood cells (leukocytes)

  • Have a nucleus. Many are phagocytic cells that engulf infectious agents, others produce antibodies or directly attack specific invading agents or infected cells
• Platelets (thrombocytes)


  • Fragments of giant cells present only in the bone marrow. When a blood vessel is damaged, they form a plug that seals the vessel, and injured tissues release molecules that help the clotting process
• Lymph


  Watery fluid that carries nutrients and proteins to your cells and tissues. It also collects any harmful substances found in your cells and tissues (filters the substances)
• Homeostasis


  The tendency of your body's tissues and organ systems to maintain a condition of balance or equilibrium
• Negative Feedback


  Keeps a variable close to a particular value
• Positive Feedback


  A mechanism that brings about a change in the same direction