Page 417 - Critical Care Nursing Demystified

402 CRITICAL CARE NURSING DeMYSTIFIED

KEY WORDS

Agranulocytes Petechiae
Albumin Plasma proteins
ANC – absolute neutrophil count Platelets
Clotting cascade Pluripotent stem cell
Erythrocyte Sepsis
Erythropoietin Septic shock
Glossitis Shift-to-the-left
Granulocytes SIRS – systemic inflammatory response
Hematopoiesis syndrome
Leukocytes Stem cells
MODS – multiple organ dysfunction RBCs – red blood cells
syndrome Reticulocyte
Neutropenia WBCs – white blood cells

Anatomy and Physiology of the Hematologic System Downloaded by [ Faculty of Nursing, Chiangmai University 5.62.158.117] at [07/18/16]. Copyright © McGraw-Hill Global Education Holdings, LLC. Not to be redistributed or modified in any way without permission.

1 Hematopoiesis is the production and maturation of blood cells in the body.
Blood consists of plasma, red blood cells, white blood cells, platelets, and lym-
phocytes. Plasma is the largest component of blood and includes water along
with the plasma proteins albumin, globulin, and fibrinogen. Albumen is impor-
tant in maintaining fluid balance in the vascular space by acting like a magnet
to hold on to water. Globulin is necessary for immune responses, and fibrinogen
is important for clotting.
Red blood cells (RBCs) or erythrocytes are the most numerous type of cell
in the blood. In their mature state, RBCs contain no nucleus so they cannot
reproduce and must be constantly formed. They are flexible, biconcavelike, and
move quickly through the vascular system. RBCs have a short life of only 120
days, degrading as they age with excess iron converted to bilirubin. Bilirubin is
reused by the liver or excreted in the urine. If it cannot be excreted, bilirubin
can be excreted in the skin, creating the yellow color seen in jaundice.
RBCs are 90% hemoglobin. Hemoglobin is made up of iron, which binds
with globin which attaches to and carries the oxygen molecule. The primary
role of RBCs is to carry oxygen-rich arterial blood to all cells and major organs.
Pluripotent stem cells stimulated by erythropoietin create RBCs. Immature
forms of RBCs are called reticulocytes. Reticulocytes are released when