Circulatory System: Red Blood Cells, White Blood Cells, and Coagulation

Vocabulary practice flashcards covering red blood cells, white blood cell types, hemoglobin structure, mechanisms of blood clotting, and blood grouping basics based on the lecture notes.

Red Blood Cell Dimensions

The average physical dimensions of a human erythrocyte, measuring approximately $7.5\,\mu\text{m}$ in diameter and $2.5\,\mu\text{m}$ in thickness.

Red Blood Cell Lifespan

The average operational lifespan of a mature red blood cell in human circulation, lasting approximately $120\text{ days}$ before being removed and destroyed by phagocytes.

Hypoxia

A physiological condition characterized by an inadequate or decreased supply of oxygen delivered to body tissues.

Erythropoietin (EPO)

A hormone secreted primarily by the kidneys in response to hypoxia that stimulates the bone marrow to produce red blood cells.

Adult Hemoglobin Structure

A protein with quaternary structure consisting of four polypeptide chains (two alpha chains and two beta chains), each surrounding a central iron-containing heme group capable of binding oxygen.

Fetal Hemoglobin

A form of hemoglobin present in developing fetuses consisting of two alpha chains and two gamma chains, exhibiting a higher affinity for oxygen than adult hemoglobin to extract oxygen at lower partial pressures.

Stercobilin

A brown pigment produced in the large intestine through the breakdown of bilirubin by bacteria, giving feces its characteristic brown color.

Urobilin

A yellow pigment derived from urobilinogen in the kidneys that gives urine its characteristic yellow color.

Pernicious Anemia

A nutritional anemia caused by a deficiency in vitamin $B_{12}$ or folic acid.

Hypochromic Anemia

The most common type of anemia, affecting $90\%$ of anemia cases in women, caused by a deficiency in iron.

Leukocytosis

An abnormally high total count or excessive production of white blood cells in the blood.

Leukopenia

An abnormal decrease in the production of white blood cells, leading to a reduced white blood cell count.

Neutrophils

The most abundant granulocytes ($60\%$ to $70\%$ of white blood cells), measuring $12$ to $15\,\mu\text{m}$ in diameter with a multi-lobed nucleus, functioning as microphagocytes to engulf bacteria.

Eosinophils

Granulocytes ($2\%$ to $4\%$ of white blood cells) with a bilobed nucleus and large granules that stain orange-red; their levels increase during allergic reactions and parasitic infections.

Basophils

Granulocytes comprising less than $1\%$ of white blood cells ($0.5\%$), featuring large blue-black staining granules and a bilobed nucleus that release histamine and heparin during allergic responses.

Monocytes

The largest agranulocytes ($20$ to $25\,\mu\text{m}$ in diameter, $3\%$ to $8\%$ of white blood cells), featuring a lightly staining nucleus slightly indented on one side.

Lymphocytes

Agranulocytes ($20\%$ to $30\%$ of white blood cells, $8$ to $10\,\mu\text{m}$ in size) with a round, dark-staining nucleus, consisting of B cells, T cells, and natural killer cells.

Extrinsic Clotting Mechanism

A blood coagulation pathway triggered by damaged tissues outside the blood vessels releasing factors like tissue thromboplastin.

Intrinsic Clotting Mechanism

A blood coagulation pathway triggered inside blood vessels when vessel wall damage exposes underlying collagen fibers, causing platelet adhesion and activation.

Thrombus

An abnormal blood clot that forms within an intact blood vessel.

Embolus

A blood clot or foreign mass that dislodges from its site of origin and travels through the bloodstream, potentially blocking blood flow elsewhere.

Plasmin (Fibrinolysin)

An active enzyme converted from plasminogen that slowly breaks down and dissolves a fibrin clot as tissue healing occurs.

Universal Donor

Blood type O negative, which lacks A, B, and Rh antigens on its red blood cell membranes, making it safe for emergency transfusion to any recipient.

Universal Recipient

Blood type AB positive, which contains A, B, and Rh antigens and lacks anti-A, anti-B, and anti-Rh antibodies in the plasma, allowing it to receive blood of any type.