anatomy 2 exam 1

• cardio system consists of: blood, heart, blood vessels
• blood: a connective tissue composed of plasma (liquid ECM) and formed elements (cells and fragments)
• blood transports: oxygen, carbon dioxide, nutrients, hormones, heat, and metabolic wastes
• metabolic waste: energy/heat, water, carbon dioxide
• blood regulates: pH, body temperature, water content of cell
• blood protects through clotting, combating toxins and microbes through phagocytic WBCs or specialized blood plasma proteins
• blood is

  • more viscous and denser than water
  • slightly alkaline (7.35-7.45)
  • slightly higher temperature than oral/body temp
  • men volume: 5-6L
  • women volume: 4-5L
  • 8% of total body weight
• whole blood is composed of plasma with dissolved solutes (55%) and formed elements (45%)
• plasma is 91.5% water and 8.5% solutes
• plasma proteins mainly from liver (7%)

  • albumins: 54%, maintain blood osmotic pressure (packing peanut)
  • globulins: 38%, includes antibodies for immunity
  • fibrinogen: 7%, key for blood clotting
• other solutes in plasma: electrolytes, nutrients, gases, regulatory enzymes, hormones and vitamins, and waste products
• red blood cells (99% of formed elements): transport oxygen
• white blood cells (1%): immunity
• platelets: cell fragments, help clotting
• pluripotent stem cells give rise to two kinds of stem cells
• myeloid stem cells: differentiate into precursor cells (blasts) for RBCs, platelets, 3 kinds of granulocytes and monocytes
• lymphoid stem cells: differentiate into precursor cells (lymphoblasts) for two kinds of lymphocytes in red bone marrow, then complete development in lymphatic tissues
• formation of blood cells from hematopoietic stem cells in red bone marrow controlled by hormones
• the hormones that control blood cell formation are erythropoietin (RBC), thrombopoietin (platelets), and cytokines and other hemopoietic growth factors
• erythrocytes (RBC): mature cells that are biconcave discs that lack nuclei and other major organelles, so cannot undergo mitosis or extensive metabolic activities
• erythrocytes contain oxygen carrying hemoglobin, this gives RBCs their red color
• • globin part of hemoglobin is 4 polypeptide chain protein that can bind and transport carbon dioxide
  • heme part of hemoglobin is ring-like non-protein pigment with iron that binds to oxygen
• erythrocytes are produced and enter circulation at the same rate they are destroyed
• erythrocytes live only about 120 days

  • fragile, old, or damaged RBCs destroyed by phagocytic macrophages in spleen and liver
• hemoglobin is broken down and recycled

  • amino acids from globin are used to make proteins
  • iron from heme is transported by transferrin (binds to iron and transports across) to red bone marrow to be used to synthesize hemoglobin for new RBCs
  • non-iron portion of heme is eventually converted to bilirubin and secreted into bile that passes into the intestines
• erythropoiesis: formation of RBCs

  • begins in red bone marrow
  • proerythroblast ejects its nucleus, becomes a reticulocyte, and enters the bloodstream
  • within 1-2 days they become a mature erythrocyte
  • typically, rate equals blood cell destruction to maintain oxygen-carrying capacity of blood
• hypoxia: (cellular O2 deficiency) stimulates release of erythropoietin by the kidneys, that speeds the development of reticulocytes
• type a blood: A antigen (anti-B antibodies)
• type b blood: B antigen (anti-A antibodies)
• type ab blood: both a and b antigen (no antibodies)
• type o blood: neither antigen (both antibodies a and b)
• blood type is based on genetically determined cell surface protein antigens called agglutinogens
• plasma typically contains antibodies called agglutinins which react with antigens not on RBC surface
• blood groups are based on presence or absense of antigen (ABO and Rh groups)
• plasma contains antibodies to antigen not found on cells
• incompatible when recipients antibodies (agglutinins in plasma) bind to antigens on the donated blood RBCs which causes agglutination (clumping) and hemolysis (RBC rupture)
• universal recipients: type AB; in theory can receive blood from donors of all 4 blood types because they have no antibodies to attack the donated RBCs
• universal donor: type O; in theory can donate blood to all 4 blood types because no antigens on RBCs to trigger transfusion reaction
• + or -: based on presence or absence of the Rh antigen, first discovered in the Rhesus monkey
• type Rh+ blood has the antigen

  type Rh- blood does not have the antigen