BIO310: Blood and Immune System

What is hemostasis?

The process that stops blood loss and keeps blood within a damaged vessel.

What initiates the clotting process?

Platelet activation occurs when platelets adhere to exposed collagen in a damaged vessel.

What are platelets?

Small fragments of megakaryocytes that play a crucial role in blood clotting.

What is the lifespan of a platelet?

Platelets live for about ten days.

What is the role of vasoconstriction in hemostasis?

It provides a temporary decrease in pressure to help establish a secure seal in damaged vessels.

What is the positive feedback mechanism in platelet aggregation?

Activated platelets release factors that activate more platelets, reinforcing the platelet plug.

What are the two pathways involved in coagulation?

Intrinsic pathway and extrinsic pathway.

What triggers the intrinsic pathway of coagulation?

Proteins that are already present in the plasma activate factor XII.

What triggers the extrinsic pathway of coagulation?

Damaged tissue exposes tissue factor (factor III), which activates factor VII.

What is the common pathway in coagulation?

It starts with the activation of factor X, leading to the conversion of prothrombin into thrombin.

What is fibrinolysis?

The process of breaking down a clot, involving plasmin derived from plasminogen.

What are anticoagulants?

Substances that inhibit coagulation, such as heparin and antithrombin III.

What is the immune system's primary function?

To protect the body from pathogens and remove dead or damaged cells.

What is the difference between innate and acquired immunity?

Innate immunity is nonspecific and present at birth, while acquired immunity is specific and develops after exposure to pathogens.

What is an antibody?

A protein secreted by immune cells that binds to antigens to make them more visible to the immune system.

What are cytokines?

Proteins released by one cell that influence the growth or activity of another cell.

What is Pemphigus Vulgaris?

An autoimmune disease causing blistering and sores of the skin and mucous membranes.

What can cause failure of the immune response?

Incorrect response (autoimmune diseases), overactive response (allergies), or lack of response (immunodeficiency diseases).

What is the role of leukocytes in tissue repair?

They remove debris and contribute to the healing process after a clot has formed.

How does the body prevent coagulation from spreading to uninjured areas?

Normal endothelium releases prostacyclin, which inhibits platelet aggregation.

What is the significance of thrombin in coagulation?

Thrombin converts fibrinogen into fibrin, forming a stable clot.

What is the function of the immune response's chemical signals?

They facilitate communication and coordination among immune cells during an immune response.

What is the first line of defense in the immune system?

The innate immune response, which includes physical barriers and nonspecific responses.

What is the role of memory in the immune system?

It allows for a rapid response upon subsequent exposure to the same pathogen.

What is a thrombus?

A blood clot that forms in a vessel and can obstruct blood flow.

What is the role of thromboxane A2 in hemostasis?

It is a platelet-activating factor that promotes aggregation and vasoconstriction.

What is the function of the endothelium in coagulation?

It releases anticoagulants to prevent excessive coagulation and maintain blood flow.

What are the two main components of blood?

Plasma and formed elements

What percentage of total extracellular fluid does blood comprise?

Approximately 25%

How much blood does a 70 kg man have?

About 5 kg (approximately 7% of body weight or 5L)

What is the primary component of plasma?

Water (92%)

What are erythrocytes?

Red blood cells that transport O2 and CO2

What are platelets also known as?

Thrombocytes

What is the function of leukocytes?

To participate in the immune response and defense

What are the five types of leukocytes?

Lymphocytes, Monocytes, Neutrophils, Eosinophils, Basophils

What is hematopoiesis?

The production of blood cells in the bone marrow

What regulates the production of erythrocytes?

Erythropoietin (EPO)

What triggers the synthesis and release of EPO?

Tissue hypoxia

What is the lifespan of red blood cells?

Approximately 120 days

What is a hematocrit reading?

A measure of the percentage of red blood cells in blood volume

What is anemia?

A condition characterized by low hemoglobin content in blood

What is the difference between hemolytic anemia and iron-deficiency anemia?

Hemolytic anemia involves faster rupture of RBCs, while iron-deficiency anemia results from inadequate hemoglobin production.

What genetic mutation causes sickle cell disease?

A mutation in the beta chain of hemoglobin, specifically a change from valine to glutamate at position 146.

What is the primary source of ATP for mature erythrocytes?

Glycolysis

What happens to older red blood cells?

They become fragile and are prone to rupture.

What is the role of transferrin in iron transport?

Transferrin carries iron from the diet to the red bone marrow.

What is the significance of the biconcave shape of red blood cells?

It allows flexibility to squeeze through vessels and respond to osmotic changes.

What is the function of colony-stimulating factors (CSF)?

To regulate leukocyte production.

What is the role of thrombopoietin (TPO)?

To regulate megakaryocyte growth and platelet production.

What is the composition of mature erythrocytes?

They are filled with enzymes and hemoglobin and lack a nucleus.

What is the primary function of hemoglobin?

To transport oxygen in the blood.

What happens to hemoglobin during its breakdown?

Amino acids are recycled, and heme is converted to bilirubin and excreted.