Notebook LM Flashcards Unit 4

What are the three primary functions of blood?

Transportation, defense, and maintenance of homeostasis.

What component of blood is primarily responsible for transporting oxygen and carbon dioxide?

Red blood cells (erythrocytes).

Which components of blood are involved in the body's defense mechanisms?

White blood cells, platelets, and antibodies.

How does blood help maintain homeostasis in terms of temperature?

By changing the flow of blood to either conserve or dissipate heat.

A centrifuged blood sample is separated into three main components. What are they?

Plasma, the buffy coat, and red blood cells (hematocrit).

What is the buffy coat composed of?

White blood cells (leukocytes) and platelets (thrombocytes).

What is the most abundant protein in blood plasma and its primary function?

Albumin, which is the most significant contributor to osmotic pressure and acts as a binding protein.

What is the function of alpha and beta globulins in plasma?

They transport iron, lipids, and fat-soluble vitamins, and contribute to osmotic pressure.

What is the function of gamma globulins (antibodies)?

They are involved in immunity and are produced by plasma cells.

Which plasma protein, produced by the liver, is essential for blood clotting?

Fibrinogen.

The process of blood cell formation is known as _.

hemopoiesis

All formed elements of blood originate from what type of cell?

Hematopoietic stem cells (hemocytoblasts).

Hematopoietic stem cells differentiate into which two major cell lines?

Myeloid stem cells and lymphoid stem cells.

Which blood cells are derived from myeloid stem cells?

Erythrocytes, platelets, basophils, neutrophils, eosinophils, and monocytes.

Which blood cells are derived from lymphoid stem cells?

B cells, T cells, and Natural Killer (NK) cells.

What is the specific term for the formation of red blood cells?

Erythropoiesis.

What is the specific term for the formation of white blood cells?

Leukopoiesis.

What is the specific term for the formation of platelets?

Thrombopoiesis.

What is a reticulocyte?

An immature erythrocyte that has been released into circulation from the bone marrow.

Describe the basic anatomy of a mature erythrocyte.

It is a biconcave disc that lacks a nucleus and organelles.

What is the approximate lifespan of an erythrocyte?

About 120 days.

What happens to old or damaged erythrocytes?

They are removed from circulation by macrophages, primarily in the spleen, liver, and bone marrow.

Hemoglobin is composed of four protein chains called and a red, iron-containing pigment called .

globin; heme

During the breakdown of hemoglobin, the globin portion is broken down into what?

Amino acids, which are reused for protein synthesis.

During hemoglobin breakdown, the heme portion is converted first to (a green pigment) and then to (a yellow pigment).

biliverdin; bilirubin

How are iron ions from degraded hemoglobin transported in the blood?

They bind to the blood protein transferrin.

Where can iron from hemoglobin be stored, and in what form?

It can be stored in the liver or spleen bound to the protein ferritin.

Term: Anemia characterized by smaller than normal red blood cells.

Microcytic anemia.

Term: Anemia characterized by larger than normal red blood cells.

Macrocytic anemia.

Term: An overproduction of red blood cells.

Polycythemia.

The process by which leukocytes squeeze through adjacent cells in a blood vessel wall is called _.

emigration or diapedesis

What is positive chemotaxis?

The movement of a cell toward a chemical attractant, such as leukocytes moving to an injury site.

Which are the most numerous leukocytes, acting as rapid responders and effective phagocytes?

Neutrophils.

Which granular leukocyte has a multi-lobed nucleus and originates from myeloid stem cells?

Neutrophil.

Which leukocytes are most effective against parasitic worms and contain antihistamines in their granules?

Eosinophils.

Which granular leukocyte is the least common and releases histamine to trigger inflammation?

Basophils.

Which agranular leukocyte, derived from myeloid stem cells, differentiates into macrophages?

Monocytes.

Which category of leukocytes arises from the lymphoid stem cell line?

Lymphocytes (T cells, B cells, NK cells).

Term: A medical condition where too few leukocytes are produced.

Leukopenia.

Term: A type of cancer involving an abundance of leukocytes.

Leukemia.

Term: A form of cancer where masses of malignant T or B cells collect in lymph nodes and other organs.

Lymphoma.

Platelets (thrombocytes) are fragments of which large cell?

Megakaryocytes.

What is the primary function of thrombocytes (platelets)?

Hemostasis (stopping blood flow).

What are the three mechanisms involved in hemostasis?

Vascular spasm, platelet plug formation, and coagulation.

What is the first step of hemostasis, where smooth muscle in the vessel wall contracts?

Vascular spasm.

During platelet plug formation, platelets are activated by chemicals and contact with _, causing them to become spiked and sticky.

collagen

The final step of hemostasis, coagulation, involves the conversion of to , which forms a mesh.

fibrinogen; fibrin

The extrinsic coagulation pathway is initiated by damage to surrounding tissues, which releases what factor?

Tissue factor (Factor III).

The intrinsic coagulation pathway is typically initiated by damage to what?

The vessel wall itself.

Both the intrinsic and extrinsic pathways of coagulation converge to activate which factor, initiating the common pathway?

Factor X.

In the common pathway, activated Factor X joins with Factor V to convert into .

prothrombin (Factor II); thrombin

What is the role of thrombin in the common pathway?

It converts fibrinogen (Factor I) into fibrin.

The process of breaking down a clot is called and is accomplished by the enzyme .

fibrinolysis; plasmin

What is hemophilia?

A disorder characterized by the inadequate production of one or more clotting factors.

Term: An excessive number of platelets that increases the risk for excessive clot formation.

Thrombocytosis.

An unwanted blood clot that forms in an unbroken vessel is called a _.

thrombus

A piece of a thrombus that breaks free and travels through the bloodstream is known as an _.

embolus

What are the primary lymphoid organs, and what are their functions?

Bone marrow (site of hemopoiesis and B cell maturation) and the thymus (site of T cell maturation).

What are the secondary lymphoid organs?

Lymph nodes, spleen, and lymphoid nodules (like tonsils and MALT).

What is the primary function of lymph nodes?

To filter lymph and serve as a site for adaptive immune activation.

What are the key functions of the spleen?

It filters blood, removes old red blood cells, fights blood pathogens, and acts as a blood reservoir.

What is the main difference between innate and adaptive immunity?

Innate immunity is nonspecific and present at birth, while adaptive immunity is specific to antigens and has memory.

Give an example of a physical barrier to infection for the skin.

Tight junctions between cells or the layer of keratin.

Give an example of a chemical barrier to infection in the digestive tract.

Lysozyme in saliva or the low pH of gastric juice.

Which cells of the innate immune system primarily destroy infected host cells and cancer cells?

Natural Killer (NK) cells.

How do Natural Killer (NK) cells recognize their targets?

They identify cells that lack surface MHC class I antigens.

What two substances do NK cells and Cytotoxic T cells secrete to induce apoptosis in target cells?

Perforin and granzymes.

What is an interferon?

A cytokine released by a virus-infected cell that signals nearby uninfected cells to resist viral infection.

The classical pathway of the complement system is activated by what?

An antibody binding to an antigen on a pathogen.

In the complement system, what is the role of C3b?

It binds to the surface of a pathogen, tagging it for destruction (opsonization).

The final product of the complement cascade is the _, which pokes holes in the pathogen's membrane.

membrane attack complex (MAC)

What is opsonization?

The coating of a pathogen with proteins (like antibodies or C3b) to enhance phagocytosis.

What is an antigen?

A substance, typically foreign, that causes the body to produce specific antibodies or sensitized T cells.

Upon activation, B cells undergo clonal expansion and differentiate into what two cell types?

Plasma cells and memory B cells.

What is the function of plasma cells?

They secrete large quantities of soluble antibodies.

What is the role of Major Histocompatibility Complex (MHC) I molecules?

They present endogenous antigens (from within the cell, like viral proteins) to cytotoxic T cells.

What is the role of Major Histocompatibility Complex (MHC) II molecules?

They are found on antigen-presenting cells (APCs) and present exogenous antigens (from outside the cell) to helper T cells.

Which type of T helper cell activates B cells to produce antibodies?

Th2 cells.

Which type of T helper cell activates cytotoxic T cells and NK cells?

Th1 cells.

Which immunoglobulin class is the most abundant in serum and is the main antibody of secondary responses?

IgG.

Which immunoglobulin class is secreted into mucus, tears, and saliva?

IgA (as Secretory IgA).

Which immunoglobulin class is the main antibody of primary responses and exists as a pentamer?

IgM.

Which immunoglobulin class is involved in allergic reactions and antiparasitic activity?

IgE.

Which immunoglobulin is the only class that can cross the placenta?

IgG.

The process by which antibodies block the adhesion of bacteria and viruses to mucosa is called _.

neutralization

How do Cytotoxic T cells recognize infected host cells?

They recognize foreign antigens presented on MHC I molecules on the surface of the infected cell.

What is the major difference between how NK cells and Cytotoxic T cells target cells?

NK cells target cells lacking MHC-I, while Cytotoxic T cells target cells presenting a specific foreign antigen on MHC-I.

In the immune response to cancer, what is the role of antigen-presenting cells (APCs)?

They patrol the body, pick up cancer antigens, and present them to T cells in the lymph nodes to initiate an immune response.