Chapter 17: Blood (Part 1) Vocabulary Flashcards

Blood

The life-sustaining transport vehicle of the cardiovascular system that performs transport, regulation, and protection functions in the body.

Plasma

The nonliving fluid matrix of blood that makes up about 55% of whole blood and consists of about 90% water along with over 100 dissolved solutes.

Formed Elements

The living blood cells suspended in plasma, comprising erythrocytes (red blood cells), leukocytes (white blood cells), and thrombocytes (platelets).

Erythrocytes

Red blood cells (RBCs); small (7.5 μm), anucleate biconcave discs filled with hemoglobin that function primarily in respiratory gas transport.

Leukocytes

White blood cells (WBCs); the only formed elements that are complete cells with a nucleus and organelles, functioning in body defense against disease.

Thrombocytes

Platelets; cell fragments in the blood that participate in initiating blood clot formation.

Hematocrit

The percentage of total blood volume composed of red blood cells, with normal values being 47% ± 5% for males and 42% ± 5% for females.

Buffy Coat

A thin, whitish layer formed between the plasma and erythrocyte layers after centrifuging whole blood, consisting of leukocytes and platelets (< 1% of whole blood).

Albumin

The most abundant plasma protein (60% of plasma proteins), produced mostly by the liver, which serves as a molecular carrier, a blood buffer, and a major contributor to plasma osmotic pressure.

Hemoglobin (Hb)

An iron-containing protein in erythrocytes composed of four polypeptide globin chains (two alpha, two beta) each bound to a heme pigment, which reversibly binds oxygen.

Oxyhemoglobin

The ruby red protein complex formed when oxygen loads onto hemoglobin in the lungs.

Deoxyhemoglobin

The dark red protein complex (also known as reduced hemoglobin) formed when oxygen unloads from hemoglobin in body tissues.

Carbaminohemoglobin

The compound formed when carbon dioxide binds to hemoglobin in tissues, accounting for about 20% of CO2 transport in blood.

Hematopoiesis

The process of formation of all blood cells, occurring within the red bone marrow.

Hematopoietic Stem Cells (Hemocytoblasts)

Stem cells in red bone marrow that give rise to all formed elements in the blood.

Erythropoiesis

The specific process of red blood cell formation, which takes about 15 days from stem cell to mature erythrocyte.

Reticulocyte

An immature stage of erythrocyte development that still contains a small amount of ribosomes; its count in blood indicates the rate of RBC formation.

Erythropoietin (EPO)

A glycoprotein hormone released primarily by the kidneys in response to hypoxia that stimulates erythropoiesis in red bone marrow.

Bilirubin

A yellow pigment formed from the degradation of heme during RBC breakdown, which is picked up by the liver and secreted in bile into the intestines.

Stercobilin

A pigment formed from the bacterial breakdown of bilirubin in the intestines that gives feces its brown color.

Anemia

A condition characterized by abnormally low oxygen-carrying capacity of the blood, leading to symptoms such as fatigue, pallor, dyspnea, and chills.

Hemorrhagic Anemia

Anemia caused by rapid blood loss, such as from a severe wound.

Chronic Hemorrhagic Anemia

Anemia caused by slight but persistent blood loss over time, such as from hemorrhoids or a bleeding ulcer.

Iron-Deficiency Anemia

Anemia resulting from inadequate iron intake, impaired iron absorption, or secondary blood loss, producing small, pale erythrocytes (microcytes).

Pernicious Anemia

An autoimmune disorder that destroys stomach mucosa, preventing intrinsic factor production and vitamin B12 absorption, leading to large, undivided RBCs called macrocytes.

Renal Anemia

Anemia caused by insufficient erythropoietin (EPO) production, usually accompanying renal disease.

Aplastic Anemia

Anemia caused by the destruction or inhibition of red bone marrow by drugs, chemicals, radiation, or viruses, affecting all formed element lines.

Thalassemias

A group of inherited blood disorders common in people of Mediterranean descent, where one globin chain is absent or faulty, producing thin, delicate RBCs deficient in hemoglobin.

Sickle-Cell Anemia

A genetic disease caused by a single amino acid substitution in the beta chain of hemoglobin (Hb-S), causing erythrocytes to become crescent-shaped under low oxygen levels.

Polycythemia

An abnormal excess of erythrocytes that increases blood viscosity, leading to sluggish blood flow.

Polycythemia Vera

A bone marrow cancer characterized by the overproduction of erythrocytes, which can cause hematocrit levels to reach up to 80%.

Diapedesis

The process by which white blood cells slip out of capillary blood vessels into surrounding tissue spaces.

Leukocytosis

A elevated white blood cell count over 11,000 cells per μl, which serves as a normal physiological response to infection.

Granulocytes

A category of leukocytes containing visible cytoplasmic granules when stained, including neutrophils, eosinophils, and basophils.

Agranulocytes

A category of leukocytes that lack visible cytoplasmic granules, including lymphocytes and monocytes.

Neutrophils

The most abundant leukocytes (50–70%), containing 3 to 6 nuclear lobes and lilac-staining granules with hydrolytic enzymes or defensins; active phagocytic 'bacteria slayers'.

Eosinophils

Leukocytes making up 2–4% of WBCs with bilobed nuclei and red-staining granules containing digestive enzymes that target large parasitic worms and play roles in allergies and asthma.

Basophils

The rarest leukocytes (0.5–1%), containing purplish-black granules filled with histamine to induce inflammation and attract WBCs to inflamed tissue sites.

Histamine

An inflammatory chemical contained in basophil granules that acts as a vasodilator and attracts white blood cells to sites of inflammation.

Lymphocytes

Agranulocytes accounting for 25–45% of WBCs, featuring large circular nuclei with thin rims of blue cytoplasm; crucial to immune responses and classified as T or B cells.

T Lymphocytes (T cells)

Lymphocytes that function directly against virus-infected cells and tumor cells.

B Lymphocytes (B cells)

Lymph