Cardiovascular Cardiovascular System: Blood II and System: Blood II and

IIIIII

Chapter 11Chapter 11

Blood GroupingBlood Grouping

Surfaces of erythrocytes have Surfaces of erythrocytes have antigens and the plasma contains antigens and the plasma contains antibodies. Each antibody is specific antibodies. Each antibody is specific for an antigen. for an antigen.

ABO Blood GroupsABO Blood Groups ABO grouping is based on the presence or ABO grouping is based on the presence or

absence of two possible antigens – A and B. The absence of two possible antigens – A and B. The presence of these antigens is based on heredity.presence of these antigens is based on heredity.

Persons with type A antigen have type A blood, Persons with type A antigen have type A blood, with type B antigen have type B blood, with both with type B antigen have type B blood, with both A and B antigens have AB blood, lacking antigens A and B antigens have AB blood, lacking antigens A and B have type O blood.A and B have type O blood.

Conversely, the antibodies present in the blood Conversely, the antibodies present in the blood are opposite to the antigens. They are not are opposite to the antigens. They are not present at birth, but develop over several months present at birth, but develop over several months following birth.following birth.

O = universal donor and AB = universal recipientO = universal donor and AB = universal recipient

ABO continuedABO continued

Rh Blood GroupsRh Blood Groups

Rh positive individuals have a certain Rh Rh positive individuals have a certain Rh antigens on the surface of their erythrocytes. antigens on the surface of their erythrocytes. Rh negative individuals do not have this Rh negative individuals do not have this antigen. antigen.

Major concern for pregnant women due to an Major concern for pregnant women due to an Rh differential during birth. An Rh positive Rh differential during birth. An Rh positive fetus in an Rh negative mother causes the fetus in an Rh negative mother causes the mother to produce Rh antibodies if exposed to mother to produce Rh antibodies if exposed to the baby’s blood results in the potential for the baby’s blood results in the potential for Hemolytic disease of the newborn (HDN) in Hemolytic disease of the newborn (HDN) in the second pregnancy if not treated.the second pregnancy if not treated.

HemoglobinHemoglobin Consists of 4 protein Consists of 4 protein

chains and 4 heme chains and 4 heme groups.groups.

The protein is the The protein is the globin and is bound to globin and is bound to one heme, which is a one heme, which is a red-pigment red-pigment containing an atom of containing an atom of iron.iron.

The four globins in The four globins in normal adult normal adult hemoglobin consists hemoglobin consists of two alpha chains of two alpha chains and two beta chains.and two beta chains.

Abnormal hemoglobins Abnormal hemoglobins are less effective at are less effective at attracting oxygen than is attracting oxygen than is normal hemoglobin. normal hemoglobin. What disorder could this What disorder could this result in?result in?

Iron is needed for the Iron is needed for the normal function of normal function of hemoglobin due to the hemoglobin due to the fact that it is the binding fact that it is the binding site for oxygen. How site for oxygen. How does that relate to the does that relate to the symptoms of the symptoms of the disorder identified disorder identified above?above?

Hemoglobin Continued:Hemoglobin Continued: Iron absorption is Iron absorption is

regulated according regulated according to need, and iron to need, and iron deficiency can deficiency can result in anemia.result in anemia.

When hemoglobin is When hemoglobin is exposed to oxygen, exposed to oxygen, 1 molecule of 1 molecule of oxygen becomes oxygen becomes associated with associated with each heme group. each heme group.

Carbon dioxide is Carbon dioxide is also transported, also transported, but it attaches to but it attaches to the amino groups the amino groups of the globin of the globin molecule. molecule.

Hemostasis:Hemostasis: DefinedDefined: : the arrest of the arrest of

bleeding.bleeding. 3 Stages: Vascular spasm, 3 Stages: Vascular spasm,

platelet plug formation, platelet plug formation, and coagulation.and coagulation.

Vascular spasmVascular spasm: : contraction of smooth contraction of smooth muscle within the wall of muscle within the wall of the blood vessels. the blood vessels. Constriction can close the Constriction can close the vessel completely stopping vessel completely stopping the flow of blood the flow of blood immediately, but immediately, but temporarily.temporarily.

Platelet Plug FormationPlatelet Plug Formation: : Platelets attach to collagen Platelets attach to collagen fibers in the connective fibers in the connective tissue and release ADP, tissue and release ADP, thromboxane, and thromboxane, and fibrinogen. ADP acts as glue fibrinogen. ADP acts as glue causing the platelets to stick causing the platelets to stick to one another. The to one another. The platelets producing ADP platelets producing ADP attaching more platelets attaching more platelets repeatedly (what type of repeatedly (what type of feedback mechanism is feedback mechanism is this?). This results in an this?). This results in an accumulating mass of accumulating mass of platelets to form a platelet platelets to form a platelet plug temporarily repairing plug temporarily repairing the damaged vessel.the damaged vessel.

Hemostasis Continued:Hemostasis Continued:

Coagulation: When Coagulation: When a blood vessel is a blood vessel is severely damaged, severely damaged, blood clotting blood clotting results. A blood results. A blood clot is a network of clot is a network of threadlike protein threadlike protein fibers, called fibers, called fibrinogen, that fibrinogen, that traps blood cells, traps blood cells, platelets, and fluid.platelets, and fluid.

Coagulation factors, Coagulation factors, plasma proteins, are plasma proteins, are what cause a blood what cause a blood clot. Normally they clot. Normally they are inactive, but are inactive, but they are stimulated they are stimulated by the nervous by the nervous system in response system in response to injury and the to injury and the inflammatory inflammatory response.response.

Hemostasis Continued:Hemostasis Continued:

Clots, once formed, condense into a Clots, once formed, condense into a denser structure through clot retraction. denser structure through clot retraction. As the clot condenses, serum is squeezed As the clot condenses, serum is squeezed out of it. out of it.

Consolidation of the clot pulls the edges of Consolidation of the clot pulls the edges of the damaged vessel together, which can the damaged vessel together, which can help to stop the flow of blood, reduce help to stop the flow of blood, reduce infection, and enhance healing. infection, and enhance healing.

The clot is usually dissolved within a few The clot is usually dissolved within a few days after clot formation by a process days after clot formation by a process called fibrinolysis. called fibrinolysis.

411 on WBC’s411 on WBC’s

Capable of amoeboid movementCapable of amoeboid movement Can Migrate into and out of the blood Can Migrate into and out of the blood

stream.stream. Are attracted to specific chemicals Are attracted to specific chemicals

(positive chemotaxis)(positive chemotaxis) Some are capable of phagocytosis Some are capable of phagocytosis

(neutrophils, eosinophils, and (neutrophils, eosinophils, and monocytes)monocytes)