Ch. 19 The Blood

Objectives Describe the functions of the blood. Describe the physical characteristics and principal components of blood.

Blood Blood – connective tissue composed of a liquid matrix called blood plasma that dissolves and suspends cells and cell fragments

Blood Functions Transportation Oxygen from lungs to body cells Carbon dioxide from body cells to lungs Nutrients from GI tract to body cells Hormones to body cells Helps eliminate heat Regulation Regulates pH Temperature Osmotic control of cells Protection Clotting White blood cells - disease

Components of Blood Blood plasma – (55%) extracellular matrix that contains dissolved substances Straw-colored liquid, mostly water, some proteins (antibodies) Formed elements (45%) – cells and cell fragments RBCs, WBCs, and platelets If blood is centrifuged – cells sink to the bottom

Components of Blood

Red Blood Cells Erythrocytes Contain hemoglobin Oxygen-carrying protein Function in oxygen/carbon dioxide gas exchange

White Blood Cells Have nuclei, do not contain hemoglobin Different types Eosinophil, basophil, neutrophil, lymphocyte, monocyte Function in fighting infection, invaders, sometimes own cells (auto-immune disorders) Cells leave blood vessels by squeezing between endothelial or epithelial tissue Use enzymes or phagocytosis to destroy bacteria

WBC

Platelets Stop blood loss from damaged blood vessels by forming a platelet plug Then release proteins that promote blood clotting Usually live 5-9 days

Platelets

Review What are the functions of blood? What are the physical characteristics of blood? What are the primary components of blood and what do they do?

Objectives Distinguish between ABO and Rh blood groups. Explain why it is so important to match donor and recipient bloody types before administering a transfusion.

Blood Types Blood cells have surface markers called antigens ABO Blood Group RBC with A antigens – A blood type RBC with B antigens – B blood type RBC with A and B antigens – AB blood type RBC with no antigens – O blood type

Blood Types Blood plasma contains proteins called antibodies Antibodies will react with antigens if mixed Type A blood – A antigens, anti-B antibodies Type B blood – B antigens, anti-A antibodies Type AB blood – A and B antigens, no antibodies Type O blood – no antigens, anti-A and anti-B antibodies

Blood Types

Transfusions Transfusion – transfer of whole blood or blood components (RBC or plasma) Agglutination – clumping of RBCs, hemolysis occurs, kidney damage and death can result This only causes problems between recipient antibodies and donor antigens Donor antibodies become diluted in blood plasma Example (recipient) A person receives blood from (donor) B person Recipients blood contains anti-B antibodies Donor’s blood contains B antigens Antigen/antibody complex forms

Who can donate/receive to/from who?

Rh Blood Group Antigen was discovered in the rhesus monkey Rh+ people have the Rh antigen, Rh- people do not have the Rh antigen People do not naturally have anti-Rh antibodies If Rh- person receives blood from Rh+ person, immune system will make anti-Rh antibodies If they receive Rh+ blood again, the anti-Rh antibodies will cause agglutination

Who can donate/receive to/from who? + should not be given to – + can receive + or – - can give to + or – Universal donor – O- Universal recipient – AB+

Hemolytic Disease of Newborn (HDN) Fetal blood can cross placenta into maternal blood stream If baby is Rh+ and mother is Rh-, mother’s immune system starts making anti-Rh antibodies During the next pregnancy the antibodies can cross into the fetal blood If the second fetus is Rh+, agglutination can occur

HDN

Review What are the different blood groups? Which antigens/antibodies does each group have? Why does this matter during transfusions? What is HDN? How is it caused?

Review of Inheritance Blood type Punnett squares Rh Punnett squares – Rh+ is dominant to Rh- Rh+ could have Rh+/Rh+ Rh + could have Rh+/Rh- Rh- must be Rh-/Rh-