(^176) Medical-Surgical Nursing Demystified
Learning Objectives
Key Terms
Clotting factors
Ecchymosis
Epistaxis
Hematocrit
Hemoglobin
Hemolysis
Leukopenia
Lymphocytes
Macrophages
Microemboli
Petechiae
Prothrombin
PT
PTT
Purpura
Stem cells
Thrombocytopenia
Anemia
Aplastic anemia (Pancytopenia)
Iron deficiency anemia
Pernicious anemia
Disseminated intravascular
coagulation (DIC)
Hemophilia
Leukemia
Multiple myeloma
Polycythemia vera
Sickle cell anemia
Deep vein thrombosis (DVT)
Idiopathic thrombocytopenic
purpura (ITP)
1
2
3
3
4
7
8
9
5
6
10
11
12
How the Hematologic System Works
The hematologic system refers to the blood and blood-forming organs.The forma-
tion of red blood cells, white blood cells, and platelets begins in the bone marrow.
Stem cells are produced in the bone marrow. Initially, these cells are not differen-
tiated and may become red blood cells (RBCs), white blood cells (WBCs), or
platelets. In the next stage of development, the stem cell becomes committed to a
particular precursor cell, to become either a myeloid or lymphoid type of cell and
will differentiate into a particular cell type when in the presence of a specific
growth factor.
The spleen is found in the left upper quadrant of the abdomen. The spleen fil-
ters whole blood. It removes old and imperfect white blood cells, lymphocytes and
macrophages, and RBCs. The spleen also breaks down hemoglobin and stores of
RBCs and platelets.