2 main components blood can be fractioned into
plasma and cell fraction
blood plasma
-approx. 46-63% of blood volume
- ~91% of plasma is water (varies based on hydration)
formed elements fraction
red and white blood cells, also platelets
hemopoiesis/hematopoiesis
blood cell formation
erythrocytes
red blood cells; account for slightly less than half the blood volume (45%), and 99.9% of
formed elements
hematocrit
measures the % of whole blood occupied by formed elements
-commonly referred to as the VOLUME OF PACKED RED CELLS
Erythropoietin (EPO)
erythropoeisis stimulating hormone; blood doping strategies
Hemoglobin
accounts for 95% of proteins in RBCs
Recycling of hemoglobin
-Heme stripped of iron and converted to biliverdin, then bilirubin
-Globin protein fraction broken down into amino acids
-Iron recycled by being stored in phagocytes
Jaundice
Caused by failure of liver to keep up with RBC breakdown--> bilirubin diffuses out of
blood into tissues all over body, causing a yellow tint. Readily apparent in sclera and
skin
Anemia
decrease in oxygen-carrying capacity of blood
iron deficiency
hemoglobin not functional without the iron
hemorrhagic
from hemorrhage or severe blood loss; fewer RBC
anaplastic
bone marrow fails to produce enough RBC (radiation, immunologic diseases)
sickle-cell anemia
caused by mutation of the amino acid sequence of hemoglobin
-RBC is a stiffened, curved shape- gets stuck in capillaries
White blood cells
defend body against pathogens, some capable of phagocytosis, remove
toxins/wastes/damaged cells, capable of amoeboid movement and positive chemotaxis
diapedesis
white blood cells leaving bloodstream in response to chemical signals by squeezing
through vessel wall
, Neutrophil (WBC)
granulocyte; multilobed nucleus, pale red and blue cytoplasmic granules
{50-70% total WBC population, 1st response to injury}
-myeloid stem cell
Eosinophil (WBC)
granulocyte; bilobed nucleus, red cytoplasmic granules
{attracted to foreign components that have reacted with Ab's}
-myeloid stem cell
Basophil (WBC)
granulocyte; bilobed nucleus, purplish-black cytoplasmic granules
{migrate to damaged tissue and release histamine & heparin}
-myeloid stem cell
Lymphocyte (WBC)
Agranulocyte; large spherical nucleus, thin rim of pale blue cytoplasm {immune system
cells}
-lymphoid stem cell
Monocyte (WBC)
Agranulocyte; kidney-shaped nucleus, abundant pale blue cytoplasm {leaves circulation
to become macrophages}
-lymphoid stem cell
Complete Blood Count (CBC)
one of the most common clinical tests performed; measures:
-hematocrit and hemoglobin concentrations
-platelet count
-WBC count
*high neutrophil counts indicative of bacterial infections
*high eosinophil counts indicative of allergy/parasitic infections
myeloid leukemia
abnormal granulocytes or other cells of marrow
lymphoid leukemia
abnormal lymphocytes
platelets
-pieces of a megakaryocyte
-NOT CELLS: flattened discs of membrane-bound chemical sacs
steps in blood clotting (role of platelets)
1. reduce diameter of vessel
2. positive-feedback loop causing platelet aggregation to block the hole in vessel wall
3. enlargement of clot
steps in blood clotting (coagulation)
{formation of the clot; cascade}
1. Thrombin (enzyme) is activated, which converts soluble fibrinogen in the blood to
insoluble, loose fibrin threads
2. clot is a gel formed from a network of fibrin threads which trap blood cells and
platelets
3. fibrin threads pull in on vessel wall, plugging the area to prevent blood loss