Lecture 2

Flashcards covering key terms related to RBC production, types of anemia, and immunity.

Erythropoietin (EPO)

Cytokine that stimulates RBC production.

Iron

Essential dietary component needed in hemoglobin synthesis.

Folic Acid and Vitamin B12

Dietary factors needed for RBC production.

Intrinsic Factor

Substance made by stomach cells, needed for vitamin B12 absorption.

Hypoxia

Decreased oxygen delivery to kidneys; stimulus for EPO secretion.

Transferrin

Iron transport protein in the blood.

Ferritin

Protein that stores iron in the liver.

Biliverdin

Green bile pigment converted to bilirubin.

Pernicious Anemia

Condition due to Vitamin B12 deficiency caused by lack of intrinsic factor

Anemia

Decreased oxygen-carrying capacity of the blood.

Aplastic Anemia

Anemia due to bone marrow damage.

Hemolytic Anemia

Anemia due to increased RBC breakdown.

Hemorrhagic Anemia

Anemia due to blood loss.

HbS

Abnormal hemoglobin in sickle cell disease.

Immunity

Process that helps the body defend against foreign substances.

Lymphocytes (B and T cells)

WBCs that are important in acquired immunity.

Erythropoietin (EPO)

A cytokine that stimulates RBC synthesis; secreted by the kidneys in response to decreased oxygen delivery; acts on bone marrow to increase RBC production.

Hypoxia

Low oxygen concentration in the blood; caused by low blood volume, anemia, low hemoglobin, poor blood flow, or pulmonary disease.

Erythropoietin (EPO) Mechanism

Decrease in tissue oxygenation stimulates EPO release from kidneys, which stimulates hematopoietic stem cells in bone marrow, increasing RBC production and the blood's oxygen-carrying capacity, ultimately increasing tissue oxygenation.

Body iron reserve breakdown

50% from hemoglobin of dying RBCs, 25% stored in other iron-containing proteins, and 25% stored in liver bound to ferritin (a protein)

What happens to old or damaged RBCs?

They are taken up by macrophages in the spleen via phagocytosis.

Hemoglobin is broken down into what?

Heme and globin.

Heme is broken down into what?

Iron and biliverdin.

Globin is broken down into what?

Amino acids.

Vitamin B12 Absorption

Requires intrinsic factor (IF) secreted by stomach cells, forming a complex with Vitamin B12 to allow absorption in the GI tract.

Pernicious Anemia

Caused by a lack of Vitamin B12.

Anemia

Decreased oxygen-carrying capacity of the blood due to a deficiency of RBCs and/or hemoglobin.

Specific factors leading to anemia

Lack of iron, Pernicious anemia, Aplastic anemia, Chronic kidney disease,

Sickle Cell

Have abnormal Hb called HbS; sickle-shaped RBC with hard, nonflexible cell membranes; RBCs are damaged as they pass through capillaries, leading to hemolytic anemia; autosomal recessive disease.

Innate/Natural Immunity

Non-specific, no memory, fast (sec/min/h); phagocytes (neutrophils and macrophages); complement system

Acquired/Adaptive Immunity

Specific, has memory, slow (days/weeks); lymphocytes (B and T cells); antibodies and cytotoxic molecules

WBCs

Produced from pluripotent stem cells in bone marrow.

Granulocytes

Neutrophils, eosinophils, basophils.

Lymphocytes

B cells and T cells.

Lymphocytes Development

Production begins in bone marrow, migrate to thymus to complete development then return to blood.

Appropriate Immune Responses

Defense, removal of old/damaged/abnormal cells

Inappropriate Immune Responses

Allergies, autoimmune reactions