Blood2

• Cardiovascular System


  System made up of blood vessels, blood and heart. Major function is to transport nutrients, gases and hormones to the cells and pick up wastes from cells to transport them to areas of body where they are excreted
• Lymphatic System


  Network of vessels that return the fluid escaped from blood vessels back to the bloodstream. Includes lymphocytes, lymphoid tissue and lymphoid organs which fight infections and give immunity to disease

  
• Circulatory System


  Together the cardiovascular system and lymphatic system make up the circulatory system. Provides a mechanism for rapid transport of nutrients, waste products, respiratory gases and cells. Powered by the pumping action of the heart
• Functions of blood


  • Transportation (dissolved gases, nutrients, hormones and metabolic wastes)
  • Protection - Platelets in the blood and clotting proteins minimize blood loss when a blood vessel is damaged
  • Regulation - Blood regulates the pH and electrolyte composition of the interstitial fluids, Blood regulates body temperature

  
• Blood


  A specialized connective tissue. Contains cellular and liquid components

  
• Blood components


  • Blood cells : formed elements
  • Plasma : fluid portion and fibrinogen

  
• Blood volume: Males: 5 – 6 liters, Females: 4 – 5 liters
• The pH of blood is about 7.35-7.45

  
• Blood Plasma


  Straw-colored, sticky fluid portion of blood. Approximately 90% water. Contains ions, nutrients, three main proteins, dissolved gases, and waste products

  
• Hematocrit - measure of % RBC: Males: 47% ± 5%(42%-52%), Females: 42% ± 5%

  
• Erythrocytes - Red Blood Cells (RBCs)

  Oxygen-transporting cells. Most numerous of the formed elements. Made in the red bone marrow. Average lifespan 100 – 120 days

  
• RBC Structure And Function

  • Have no organelles or nuclei, Hemoglobin: Oxygen carrying protein, Biconcave shape – 30% more surface area
• Leukocytes - White Blood Cells (WBCs)


  Protect the body from infectious microorganisms. Function outside the bloodstream in loose connective tissue. Most produced in bone marrow. Lifespan of 12 hours to several years

  
• Types of Leukocytes


  • Granulocytes
  • Agranulocytes
• Granulocytes


  • Neutrophils
  • Eosinophils
  • Basophils
• Neutrophils


  Most numerous WBC (50%-70%). Phagocytize and destroy bacteria
• Eosinophils


  Compose 1 – 4% of all WBCs. Play roles in allergic reactions, parasitic infections
• Basophils


  About 0.5% of all leukocytes. Nucleus – usually two lobes. Granules secrete histamines. Function in inflammation mediation, similar in function to mast cells
• Agranulocytes


  • Lymphocytes
  • Monocytes
• Lymphocytes


  Compose 20 – 45% of WBCs. The most important cells of the immune system. Act against a specific foreign molecule (antigen). Two main classes: T cells and B cells
• Monocytes


  Compose 4–8% of WBCs. The largest leukocytes. Transform into macrophages. Phagocytic cells

  
• Platelets (Thrombocytes)


  Small cellular fragments; originate in bone marrow from giant cell (megakaryocyte). Contain several clotting factors. Involved in stopping bleeding when a blood vessel is damaged
• Hematopoiesis (Blood cells formation)


  1. Yolk sac mesoderm: in the early stages of embryogenesis

  2. Liver and spleen: Some time later , as a temporary hematopoietic tissues

  3. Bone marrow ; as the prenatal ossification of the rest of the skeleton accelerates, BM becomes an important hematopoietic tissue

  
• Lymph


  The clear, nearly colorless, alkaline fluid that occupies the space between all cells of the body. 95% water. Seeps in and out through the walls of capillaries
• Lymphatic System


  • Lymph
  • Lymphatic vessels
  • Lymphatic tissue
  • Lymphatic nodules
  • Lymph nodes
  • Tonsils
  • The spleen
  • The thymus
• Functions of Lymphatic System

  • Fluid balance
  • Fat absorption
  • Defense - Microorganism and other foreign substances are filtered from lymph by lymph nodes and from blood by the spleen. Lymphocytes and other cells destroy microorganism and other foreign substances