BLOOD:
• It is considered a connective tissue, because it consists of blood cells surrounded by a nonliving fluid matrix called blood plasma. It is the most atypical connective tissue: the fibers of blood are soluble protein molecules that become visible during blood clotting.
• It is found in blood vessels.

• Blood has three functions:

  Transportation

  Blood delivers oxygen from the lungs and nutrient from the digestive tract to all body cells; it transports carbon dioxide to the lungs and nitrogenous waste to the kidney for removal from the body; it transports hormones from their endocrine glands to their target organs.

  Regulation

  Blood helps regulate body temperature and pH in body tissues.

  Protection

  Platelets and plasma proteins prevent blood loss by forming clots when blood vessels are damaged. Antibodies, complement proteins and white blood cells fight infection.