The Blood

Functions of the Blood  Transport of gases, nutrients and waste products  Transport of processed molecules  Transport of regulatory molecules  Regulation of your ph and osmosis  Maintenance of body temperature  Protection against foreign substances  Clot formation

Composition of Blood  Blood is Connective Tissue  Formed elements 45%  Plasma 55%

Plasma  Pale yellow in color  91% water,7%proteins, 2% other ions, nutrients gases and waste products  The plasma proteins include albumin globulins fibrinogen

Formed Elements  95% are Red Blood Cells  5% are White Blood Cells and Platelets  Made through the process of hematopoiesis derived from a single stem cell.

Red Blood Cell (RBC)  Biconcave Disk (shape important for function)  Loss their nuclei and most organelles  Live for 120 days in men and 110 in females  Contains hemoglobin( a red pigmented protein )  Main function to transport Oxygen

Hemoglobin  Oxygen Transport is accomplished through Hemoglobin (98.5% of Oxygen transport)  The Hemoglobin Structure  Each protein (globin) is bound to one heme Each Heme contains one iron atom When exposed to Oxygen one Oxygen binds to the iron of each heme

Life History of a Red Blood Cell  Low Oxygen  Erythropoietin (kidney)  Bone Marrow (Increased red cells)  Increase Oxygen  120 Days  Taken up by liver and spleen  In liver broken down to heme and iron, amino acids  Fe recycled by bone marrow  Heme becomes bilirubin excreted out intestines  Fig11.4 and 11.5

Clinical Pearls: Anemia  Anemia is a common blood disorder, which occurs when the level of red blood cells (RBCs) in the body becomes too low. What is the Physiologic Problem that will result?

Causes of Anemia

excessive destruction of RBCs blood loss inadequate production of RBCs Among many other causes, anemiaanemia anemia can result from inherited disorders, nutritional problems (such as an iron or vitamin deficiency), infections, some kinds of cancer, or exposure to a drug or toxin.

 Blood Grouping

Antigen/ Antibody  Antigens are molecules that stimulate an immune response are on the surface of the red blood cells  Antibodies are proteins that recognize and neutralize the immune response are present in the plasma.

Blood Grouping  The Antigens are categorized into blood groups  The ABO and RH blood groups are the most important

The ABO Blood Group  Type A -Has type A antigens on the RBC Its Plasma Contains Anti-B antibodies  Type B- Has type B antigens on the RBC Its Plasma Contains Anti- A antibodies  Type AB-Has both types (A&B) on the RBC Its Plasma Has neither Antibody  Type O – Has neither A or B on the RBC Its Plasma Contains both Anti A and Anti B HSTLVOCA.PDF

Antigens and Antibodies Blood Type Antigens Antibodies

The Blood Transfusion  Transfusion- is the transfer of blood or blood components from one individual to another.  Donor- is the person who gives the blood  Recipient- is the person who receives the blood  Transfusion Reaction- When antibodies in the plasma of the recipient bind to antigens on the red blood cells of the donor, “molecular bridges” are formed that connect the red blood cells causing them to agglutinate and rupture the blood cells

Agglutination

“ Matchmaker, Matchmaker”

Rh (rhesus) Antigens  Also on surface of the RBC  Anti RH antibodies also circulate in blood  Can be Rh- or Rh+ The ABO blood group and Rh are designated together  A+ or A-  B+ or B-  AB+ or AB-  O+ or O- Important Implications during Pregnancy

Carbon Dioxide and OxygenTransport 70% of the carbon dioxide transported as HCO3 CO2 picked up by the red blood cells and converted by carbonic anhydrase CO2+ H H + HCO3

Leukocytes (White Blood Cells)  Granulocytes Neutrophil Basophil Eosinophil  Agranuloytes Lymphocyte Monocyte

Neutrophil  Description- nucleus with four lobes connected by thin filaments granules stain a light pink reddish purple Function- Phagocyte “eats” microorganisms and other substances

Basophil  Description- Nucleus with two indistinct lobes, cytoplasm granules stain blue Function Releases histamine, which promotes inflammation, and heparin (prevents clot formation)

Eosinophil  Description Nucleus often bilobed, cytoplasmic granules stain orange-red or bright red Function- Releases chemicals that reduce inflammation; attacks certain worm parasites

 Agranulocytes

Lymphocyte  Description round nucleus, cytoplasm forms a thin ring around the nucleus- more cytoplasm to nucleus ratio Function produces antibodies and other chemicals responsible for destroying microorganisms, contributes to allergic reactions, graft rejection, tumor control, and regulation of the immune system

Monocyte  Description Nucleus is round, kidney or horseshoe shaped contains more cytoplasm than it does lymphocytes Function- leave the blood and will enter tissue, enlarge and become Macrophages which phaogcytize bacteria and other debris

Clinical Focus  Leukemia- is a cancer in which abnormal production of one or more of the white blood cell types occur Cells are immature and abnormal so they lack their normal immunologic functions and people are more susceptible to infections

Platelets  Also known as Thrombocytes  Description- minute fragments of cells each consisting of a small amount cytoplasm surrounded by a cell membrane Function- prevent blood loss a) by forming platelet plugs which seal holes on small vessels Formation of clots to seal larger vessels

Preventing Blood Loss Vascular Spasm Platelet Plugs Blood clotting mechanisms

Control of Clot Formation  Natural – Fibrinolysis  Medical - Anticoagulants