Chapter 19 Key Terms 1/2

Hematology

study of blood

Plasma

extracellular matrix of blood: the liquid portion that contains water, proteins, nutrients, wastes & gases

Formed elements

cellular portion of blood, including erythrocytes, leukocytes & platelets

Albumin

most abundant plasma protein: maintains blood viscosity & osmolarity & transports lipids, hormones & calcium

Kwashiorkor

condition caused by severe protein deficiency leading to low blood osmolarity & extreme abdominal edema

Hemopoiesis

process of producing all formed elements of blood (RBCs, WBCs, platelets)

Colony-forming unit (CFU)

committed progenitor that produces a specific “colony” of one blood cell type

1. CFU-E à erythrocytes

2. CFU-Meg à megakaryocytes à platelets

3. CFU-GM à granulocytes & monocytes

Erythrocyte (RBC)

flexible, nucleus-free blood cell specialized for gas transport

Hemoglobin

oxygen-carrying protein inside RBCs composed of 4 globin chains & 4 heme groups

Heme

non-protein portion of hemoglobin containing iron that binds to oxygen

Proerythroblast

highly mitotic precursor cell in erythropoiesis that produces hemoglobin machinery & responds to EPO

VIT C

nutrient required for enzymes that assemble hemoglobin; deficiency reduces oxygen-carrying ability

Erythropoietin (EPO)

hormone released by kidneys that accelerate RBC production when oxygen is low

Transferrin

blood transport protein that carries recycled iron to liver or bone marrow

Stercobilin

brown pigment produced by intestinal bacteria from urobilinogen; gives feces its color

Urobilin

yellow pigment formed when kidneys convert urobilinogen; gives urine its color

Thalassemia

disorder where RBCs form normally but cannot make hemoglobin properly

Pernicious anemia

anemia caused by lack of intrinsic factor, preventing VIT B12 absorption & resulting in large, abnormal RBCs

Hemolytic anemia

anemia caused by destruction (lysis) of RBCs

Sickle-Cell Disease

genetic hemoglobin disorder causing sickle-shaped RBCs that block blood vessels & break easily

Polycythemia

excess RBCs

1. Primary due to bone marrow cancer

2. Secondary – low o2, dehydration, emphysema, high altitude

Hematocrit

test that determines % of blood composed of RBCs