Chapter 14 Blood PowerPoint Presentation to accompany Hole’s Human Anatomy and Physiology, 10 th edition , edited by S.C. Wache for Biol2064.01
You are responsible for the content of the following figures and topics: Fig. 14.1 – Blood. Fig. 14.2 - hematocrit or Percent packed RBC volume. Fig. 14.5 - Blood originates from red bone marrow. Fig. 14.3 - Blood cells. WBC develop into 3 branches. Fig. 14.14 - WBC can pass through the simple epithelia of vessels by diapedesis, RBC cannot. Fig. 14.16 - Blood composition. Read TB, p.527, on hemostasis. Fig. 14. 19, Tab. 14.10 - Damaged tissues trigger the extrinsic mechanism. Read TB, p.533, on antigens and antibodies of blood groups. Fig. 14.21, 14.22 – Key-and-Lock interaction of Antigens and Antibodies. Tab. 14.13 - Study the antibodies each blood type carries in their plasma. Tab. 14.14 - Permissible Donor Blood Types. Fig. 14.23 - incompatibility with the Rh antigen also called antigen D.
Blood Volume and Composition
Blood volume is 8% of body weight
Average adult has 5 liters of blood
Blood is 45% cells
This is also known as the hematocrit or percent packed cell volume
99% are red blood cells, remainder white blood cells and blood platelets
The hematocrit is an indicator of anemia, polycythemia, and other conditions.
Erythrocytes or RBC are synthesized in response to erythropoetin (kidney hormone)
The mature cells lack nuclei and are small, biconcave disks. They no longer can divide.
Cells consist 1/3 of hemoglobin (Hb) , the protein that carries oxygen in blood.
RBC lack mitochondria and produce ATP through glycolysis only
Red Blood Cell Destruction
Damaged or worn cells rupture in the spleen or liver.
In the spleen or liver, macrophages phagocytize and destroy cells.
Hb is broken down into globin and heme which decomposes into biliverdin .
The heme group has a central iron element to which oxygen binds.
Biliverdin is converted to bilirubin and excreted in bile via the gallbladder .
Iron is carried on transferrin to the liver were it is stored as ferritin.
Fig. 14.8 Note that, in muscle, myoglobin (Mb) binds oxygen. Mb consists of only 1 protein chain. Note the 4 protein chains that make up 1 molecule of Hb.
Erythropoiesis – RBC production
Red blood cells (RBC) are called erythrocytes.
They are produced in red bone marrow.
Average life span is 120 days.
When oxygen concentrations in the blood are low , erythropoietin is released from the kidney .
Erythropoietin operates in a negative feedback mechanism to maintain RBC homeostasis .
Required Dietary Factors
Vitamin B12 - required for DNA synthesis
- intrinsic factor necessary for absorption
Folic acid - required for DNA synthesis
Iron - required for hemoglobin synthesis
Vitamin C - increases absorption of iron
Fig. 14.7 NORMAL BLOOD ANEMIC BLOOD ane·mia : a condition in which the blood is deficient in red blood cells, in hemoglobin, or in total volume – see APLASTIC ANEMIA, HYPERCHROMIC ANEMIA, HYPOCHROMIC ANEMIA, MEGALOBLASTIC ANEMIA, MICROCYTIC ANEMIA, PERNICIOUS ANEMIA, SICKLE-CELL ANEMIA; compare OLIGOCYTHEMIA
Plasminogen is absorbed by fibrin. Plasminogen activator converts plasminogen to plasmin . Plasmin digests the clot .
Prevention of Coagulation
Prostacyclin from endothelial cells inhibits platelet aggregation.
Antithrombin inactivates thrombin.
Heparin from basophils interferes with the formation of prothrombin activator.
Note: Plasminogen activator is used together with blood thinners after a stroke !
Antigens and Antibodies
Blood cell compatibility is based on clumping or agglutination
Transfusion reaction : a reaction between red blood cell antigens = agglutinogens and protein antibodies = agglutinins in the plasma leading to agglutination and hemolysis and blockage of blood flow !
Antigens include those of the ABO group and the Rh group
ag·glu·ti·na·tion: a reaction in which particles (such as RBC or bacteria); that are suspended in a liquid, collect into clumps especially in response to antiserum added in a serological blood test, that is, as a serological response to a specific antibody. agglutination test: any of several tests based on the ability of a specific serum to cause agglutination of a suitable system and used in the diagnosis of infections, the identification of microorganisms, and in blood typing Agglutination is observed on a blood slide. Note- he·mo·ly·sis: lysis of red blood cells with liberation of hemoglobin.
Fig. 14.22 Donor RBCs: They carry the antigen A. The donor is Blood Type A. Patient Blood: The patient is blood type B and has naturally occurring antibodies called Anti-A. Patient blood after wrong transfusion: The patient blood agglutinates and hemolyses. The patient dies.
ABO blood groups are based on RBC membrane antigens A and B.
Four possible combinations
Type A contains antigen A
Type B contains antigen B
Type AB contains antigens A and B
Type O contains no antigens
ABO Blood Group
Anti-A and anti-B antibodies are produced when an antigen is absent from the cell membrane
Type A plasma contains anti-B antibodies
Type B plasma contains anti-A antibodies
Type AB plasma contains anti-A and anti-B antibodies, universal recipient
Type O plasma contains no antibodies, universal donor
Rh Blood Group (Fig. 14.23)
Rh positive indicates presence of antigen D, one of the Rh antigens
Rh negative indicates absence of Antigen D
Rh antigens, like A and B antigens are inherited and present from birth
Anti-D antibodies are not produced until after an individual is sensitized to antigen D