Blood and Cardiovascular System

What are the three main functions of blood?

Transportation, defense against pathogens, and regulation of body conditions.

What type of tissue is blood?

A fluid connective tissue.

What materials does blood transport?

Oxygen, carbon dioxide, nutrients, wastes, hormones, and other signaling molecules.

What conditions does blood help regulate?

Body temperature, pH, and water-salt balance.

What percentage of blood is plasma?

About 55%.

What percentage of blood consists of formed elements?

About 45%.

What is plasma composed of?

About 92% water and 8% solutes, including salts and plasma proteins.

What are the three categories of formed elements?

Red blood cells, white blood cells, and platelets.

What is another name for red blood cells?

Erythrocytes.

What is another name for white blood cells?

Leukocytes.

What are the three major types of plasma proteins?

Albumins, globulins, and fibrinogen.

What are the main functions of albumin?

Maintaining plasma osmotic pressure and transporting molecules; albumin is the most abundant plasma protein.

What are the main functions of globulins?

Transporting substances and, for immunoglobulins, defending against infection.

What are gamma-globulins also called?

Immunoglobulins or antibodies.

What is the function of fibrinogen?

It is a soluble plasma protein that is converted into fibrin during blood clotting.

Where are blood cells produced?

In red bone marrow.

What is hematopoiesis?

The production and differentiation of blood cells from blood stem cells.

What does the suffix -blast indicate in blood-cell terminology?

An immature precursor cell.

Which precursor develops into a red blood cell?

An erythroblast, which loses its nucleus as it matures.

What is an antigen?

A substance or molecular feature recognized by the immune system that can trigger an immune response when recognized as foreign.

What is an antibody?

A protein that specifically binds a particular antigen and helps the body eliminate it.

What determines a person's ABO blood type?

The presence or absence of A and B antigens on red blood cells.

Which ABO antibodies does a person generally develop?

Antibodies against the A or B antigens absent from their own red blood cells.

Which antigens and antibodies are present in type A blood?

A antigens on RBCs and anti-B antibodies in plasma.

Which antigens and antibodies are present in type B blood?

B antigens on RBCs and anti-A antibodies in plasma.

Which antigens and antibodies are present in type AB blood?

A and B antigens on RBCs, with neither anti-A nor anti-B antibodies in plasma.

Which antigens and antibodies are present in type O blood?

Neither A nor B antigens on RBCs, with both anti-A and anti-B antibodies in plasma.

Ignoring Rh and other blood groups, which RBC types can a type A recipient receive?

A and O.

Ignoring Rh and other blood groups, which RBC types can a type B recipient receive?

B and O.

Ignoring Rh and other blood groups, which RBC types can a type AB recipient receive?

A, B, AB, and O.

Ignoring Rh and other blood groups, which RBC types can a type O recipient receive?

O only.

What is agglutination?

Clumping of red blood cells when antibodies bind incompatible antigens on their surfaces.

Why does type A blood react against type B red blood cells?

Anti-B antibodies in type A plasma bind the B antigens on the donor RBCs.

What does Rh-positive mean?

The relevant Rh antigen is present on red blood cells.

What does Rh-negative mean?

The relevant Rh antigen is absent from red blood cells.

When can an Rh-negative person develop anti-Rh antibodies?

After exposure to Rh-positive red blood cells.

Which maternal-fetal Rh combination can lead to Rh incompatibility?

An Rh-negative mother carrying an Rh-positive fetus.

How can an Rh-negative mother become sensitized to Rh-positive blood?

Fetal Rh-positive RBCs can enter her circulation, including during birth, stimulating anti-Rh antibody production.

Why can a later Rh-positive pregnancy be affected after maternal sensitization?

Maternal anti-Rh antibodies can cross the placenta and destroy fetal RBCs.

What is hemolytic disease of the newborn?

Destruction of fetal or newborn red blood cells by maternal antibodies against incompatible RBC antigens.

How do preventive anti-Rh antibodies work in an unsensitized Rh-negative mother?

They remove fetal Rh-positive RBCs from her circulation before her immune system becomes sensitized.

According to the lecture, when is postpartum anti-Rh treatment given?

No later than 72 hours after delivery of an Rh-positive baby; the lecture also says it is repeated after another Rh-positive birth.

What structural features characterize mature human RBCs?

They lack a nucleus, have few organelles, and have a biconcave shape.

How does the biconcave shape help RBC function?

It increases surface area and flexibility.

What is the function of hemoglobin?

Binding and carrying oxygen in red blood cells.

How many oxygen molecules can one hemoglobin molecule bind?

Four O2 molecules.

What subunits make up the hemoglobin tetramer described in the lecture?

Two alpha and two beta subunits.

Approximately how many hemoglobin molecules are in one RBC?

About 280 million, according to the lecture.

What is the approximate lifespan of an RBC?

120 days.

What is erythropoiesis?

The production of red blood cells.

What stimulates the kidneys to release erythropoietin (EPO)?

Low oxygen levels, called hypoxia.

How does EPO increase oxygen-carrying capacity?

It travels to red bone marrow and stimulates red blood cell production.

Where are old or damaged RBCs removed?

Primarily in the liver and spleen.

What is anemia?

A reduced oxygen-carrying capacity of blood associated with too few RBCs or insufficient or abnormal hemoglobin.

How does sickle-cell anemia affect RBCs?

An inherited hemoglobin abnormality causes sickling, shortened RBC survival, and blockage of small vessels.

What are platelets?

Cell fragments derived from megakaryocytes in red bone marrow.

Approximately how many platelets are produced daily, according to the lecture?

About 200 billion.

What is hemostasis?

Stopping bleeding and keeping blood within vessels.

How do platelets contribute to hemostasis?

They plug damaged vessels and help initiate and support blood clotting.

What type of feedback is involved in clot formation?

Positive feedback: activation promotes further activation and clot formation.

What begins the clotting sequence shown in the lecture?

Injured vessel cells and platelets release clotting factors.

What does prothrombin activator do?

It converts prothrombin into thrombin.

What does thrombin do during clot formation?

It converts fibrinogen into fibrin.

How does fibrin form a blood clot?

Fibrin threads form a network that traps red blood cells and platelets.

Which organ produces prothrombin and fibrinogen in the lecture diagram?

The liver.

What is a thrombus?

A blood clot that forms and remains at its site of origin.

What is an embolus in the clotting example?

A detached clot or clot fragment that travels through the circulation.

What is thromboembolism?

Blockage of a vessel by a clot that formed elsewhere and traveled to it.

What is thrombocytopenia?

An abnormally low platelet count, caused by reduced production or increased breakdown.

What is hemophilia?

An inherited deficiency of a clotting factor that impairs normal blood clotting.

How do WBCs differ structurally from mature RBCs?

WBCs have nuclei and are generally larger; mature RBCs lack nuclei.

What regulates white blood cell production?

Colony-stimulating factors (CSFs) and other hormones.

Where can WBCs be found?

In the blood and in body tissues.

How long can WBCs live?

Depending on the type, from days to months or years.

Which WBCs are granulocytes?

Neutrophils, eosinophils, and basophils.

What features identify granulocytes?

Noticeable cytoplasmic granules and lobed nuclei.

Which WBCs are agranulocytes?

Lymphocytes and monocytes.

What features identify agranulocytes in the lecture?

No noticeable granules and nonlobed nuclei.

What is the main function of neutrophils?

They enter infection sites and phagocytose pathogens.

What proportion of WBCs are neutrophils in the lecture?

About 50-60%.

What are the main functions of eosinophils?

Fighting parasites and participating in allergic responses.

What proportion of WBCs are eosinophils in the lecture?

About 1-5%.

What do basophils release, and what is its effect?

Histamine, which promotes inflammation.

What proportion of WBCs are basophils in the lecture?

Less than 1%.

What do monocytes become in tissues?

Macrophages.

What proportion of WBCs are monocytes in the lecture?

About 2-10%.

Which major immune cell types are lymphocytes?

B cells and T cells are major lymphocyte types highlighted in the lecture.

What proportion of WBCs are lymphocytes in the lecture?

About 25-35%.

What is diapedesis, also called extravasation?

Movement of white blood cells out of the circulation into surrounding tissues.

What is severe combined immunodeficiency (SCID)?

An inherited disorder causing severe impairment of immune defenses and a high susceptibility to infections.

What is leukemia?

A group of cancers involving uncontrolled proliferation of blood-forming cells, commonly affecting white blood cells.

What causes infectious mononucleosis in the lecture?

Epstein-Barr virus (EBV) infection of lymphocytes.

What symptoms are associated with infectious mononucleosis?

Fatigue, sore throat, and swollen lymph nodes.

What structures make up the cardiovascular system?

The heart and blood vessels.

What are the main functions of the cardiovascular system?

Transporting blood, exchanging nutrients and wastes at capillaries, and regulating blood flow and pressure.

What is the general pathway of blood through the vessels?

Heart -> arteries -> arterioles -> capillaries -> venules -> veins -> heart.

What defines an artery?

A vessel that carries blood away from the heart.

What defines a vein?

A vessel that carries blood toward the heart.

What are arterioles?

Small arteries that lead toward capillary beds.

What are the three layers of an artery wall?

An inner endothelial layer, a thick smooth muscle layer, and an outer connective tissue layer.