BLOOD Human Biology 11

BLOOD Carries the necessities of life to the cells and takes waste from the cells What are the necessities of life? Oxygen Nutrients Hormones Antibodies What are waste products? Carbon Dioxide

WHAT IS BLOOD? Blood is composed of: Plasma (55%) Red Blood Cells (40%) White Blood Cells (1%) Platelets (4%) Bodies contain 5 L of blood

PLASMA Liquid part of blood Approx. 90% water The other 10% consist of dissolved substances that are essential for life

RED BLOOD CELLS Also known as erythrocytes Main function is to “pick up” oxygen molecules and retrieve carbon dioxide molecules Hemoglobin in the red blood cell carry the oxygen Gets its red colour from the iron in hemoglobin when it carries oxygen Iron acts as an oxygen magnet

WHITE BLOOD CELLS Also known as leukocytes Function to protect the body from infection and disease causing organisms There are many different kinds

4 CHARACTERISTICS OF WHITE BLOOD CELLS 1. Capable of moving on their own and changing their shapes 1. Phagocytosis – surround or engulf bacteria and digest their harmful material 1. Capable of recognizing antigens, which are chemicals on the surface of cells. This allows the white blood cells to know if it belongs or is foreign 1. Produce antibodies which are special proteins which are used to destroy the pathogensn (Organsims that cause disease)

VIDEO OF A WHITE BLOOD CELL CHASING A BACTERIUM

PLATELETS Are responsible for the initial stages of blood clotting Are not cells, but rather tiny fragments of white blood cells Contain a special enzyme that initiates clotting

BLOOD DISORDERS

ANEMIA occurs when there are not enough red blood cells to carry all the oxygen the body requires. People who have this condition appear tired and lack energy to work efficiently. ure=channel ure=channel

TYPES OF ANEMIA The most common types of anemia: Iron deficiency anemia – Not enough iron in diet which means that RBC can’t carry enough oxygen Sickle cell anemia – RBC take on a sickle shape (half moon or crescent) which decreases the amount of oxygen it can carry

HEMOPHILIA This blood disorder prevents normal blood clotting Bleed for a longer time than others after an injury Also may bleed internally, this bleeding can damage your organs or tissues and may be life threatening.

LEUKEMIA Cancer of bone marrow Most types increase the number of WBC and decrease the number of RBC WBC reproduce rapidly but are ineffective The body is unable to cope with infections With decreased amounts of red blood cells, the body isn’t receiving enough oxygen

MONONUCLEOSIS AKA “KISSING DISEASE” Not really a disease of the blood but it does result in the production of large numbers of WBC Most commonly transferred through saliva (hence why it is called the kissing disease) Thought to be caused by a virus that is not easy to get rid off Symptoms include: fatigue, swollen glands, fever, and sore throat.

HOW DO YOU SEEK TREATMENT? Diagnosis – the process of identifying the disease or problem Looking at blood samples can help diagnose the problem or disease What do they look for? Number of Red Blood cells Number of White blood cells Number of platelets

THE PROCESS OF BLOOD CLOTTING 1. Platelets break open at wound site and release thromboplastin. (reaction starts) 2. Thromboplastin causes calcium and prothrombin to unite and form thrombin. 3. Thrombin joins with fibrinogen to form fibrin 4. A network of fibrin threads traps red blood cells and forms a clot that plugs the wound.

BLOOD TYPES Determined by the presence or absence of antigens on RBC Determined by the presence or absence of antigens on RBC Antibodies recognize RBC as our own and will bind to RBC that they don’t recognize Antibodies recognize RBC as our own and will bind to RBC that they don’t recognize

BLOOD TYPES A, B, AB, O There are 2 kinds of antigens  A and B There are 2 kinds of antigens  A and B If antigen A is present, the blood type is A If antigen A is present, the blood type is A If antigen B is present, the blood type is B If antigen B is present, the blood type is B Blood type AB, has both antigen A and B Blood type AB, has both antigen A and B Blood type O, has no antigens Blood type O, has no antigens

ANTIBODIES AND BLOOD TYPES Antibodies found in plasma are ALWAYS opposite the antigen on RBC For example: Blood type B has antigen B on the RBC so plasma would have antibodies for antigen A Type AB blood have no antibodies Type O blood have both A and B antibodies

THE RH FACTOR The Rh factor is an antigen found on the RBC of most people If you have the antigen, you are Rh+ If you don’t have the antigen, you are Rh- The disease associated with the Rh factor is known as Hemolytic Disease of the Newborn

TRANSFUSIONS If antibodies and antigens of the same type come together, the RBC clump Why is this important? If blood type A is given blood type B, the antibodies bind to the antigens, clumping the blood which can be fatal If blood type A is given blood type B, the antibodies bind to the antigens, clumping the blood which can be fatal