Hematopoiesis Flashcards
What is HEMATOPOIESIS?
The formation of BLOOD CELLS
Where does HEMATOPOIESIS occur?
RED BONE MARROW
All formed elements of blood come from what CELL?
HEMOCYTOBLASTS (HEMATOPOIETIC STEM CELLS)
What is LEUKOPOIESIS?
Formation of LEUKOCYTES (WBCs)
What regulates LEUKOPOIESIS?
CYTOKINES (CELL signaling molecules) called CSFs
Numbers of WBCs ____ and are produced in response to ______ ______ ____________
Vary, immune system requirements
What is LEUKEMIA?
Cancer of BLOOD forming TISSUES
e.g. BONE MARROW
What is THROMBOCYTOPOIESIS?
The formation of THROMBOCYTES (PLATELETS)
What regulates THROMBOCYTOPOIESIS?
The hormone THROMBOPOIETIN (TPO)
Where is THROMBOPOIETIN (TPO) produced?
In the kidneys
How are PLATELETS formed?
Fragmentation of large CELLS called MEGAKARYOCYTES
What is ERYTHROPOIESIS?
The formation of ERYTHROCYTES (RBCs)
Approx. how long does RBC synthesis take?
3 - 5 days
Approx. how many RBCs are made per second?
About 2 million (15 mL/day)
Why do males have more RBCs?
RBC production is enhanced by steroid hormone TESTOSTERONE
What mineral is required to make O2 carrying pigment HEMOGLOBIN (Hb)?
IRON (Fe)
What is the S of HEMOGLOBIN?
4 GLOBIN proteins, 2 ALPHA and 2 BETA. 4 HEME molecules
Each HEME contains a single __ (which lies within a porphyrin ring)
Fe
How many O2 can each Fe bind?
A single one - OXYHEMOGLOBIN
What is the max. O2 HEMOGLOBIN can carry?
4
What makes CARBAMINOHEMOGLOBIN?
GLOBINS that bind to CO2
What inc. RBC synthesis?
The GLYCOPROTEIN HORMONE ERYTHROPOIETIN (EPO)
Where is EPO secreted?
From the kidneys
When is EPO secreted?
In response to HYPOXIA (O2 deficient)
HYPOXIA can be caused by these 3 things?
1) BLOOD loss
2) Dec. in O2 in BLOOD
3) Inc. in O2 demand
What happens to RBCs as they age?
They become less flexible and more fragile, thus reducing the O2 carrying capacity and HEMOLYSIS
What is the avg. lifespan of a RBC?
120 days
Which organs trap old RBCs?
The SPLEEN and LIVER
MACROPHAGES in SPLEEN and LIVER ___________ RBCs
phagocytize
