Corpuscular elements of blood

Elements of Blood
Blood includes 40 to 45% formed elements:
Red Blood Cells (erythrocytes).
White Blood Cells (leukocytes).
Platlets (thrombocytes).
55 to 60% plasma:
Transparent liquid in which the cellular components of blood are suspended

Elements of Blood
Blood Characteristics:
6 to 8% of body weight in normal healthy humans.
Density: 1060 kg/m3
Therefore, most of people have between 4.5 and 6 L of blood.

Elements of Blood
Blood Viscosity:
The viscosity of blood is in the range 0.003 to 0.006 N s/m2
Blood is a non-Newtonian fluid: its viscosity is not a constant with respect to the rate of shearing strain.
The viscosity is also dependent on the T and the volume of blood that consists of RBC (hematocrit)

Elements of Blood
A normal hematocrit is between 42 and 45%
Lower hematocrit: anemia.
Higher hematocrit: polycythemia

Elements of Blood
Erythrocytes:
Erythros: red ; kytos: hollow
Biconcave discs with a diameter of around 8 μm.

Elements of Blood
Its lifespan is around 125 days. After this they become fragile and desintegrate.
0.8% of RBC are destroyed every day, and the same amount is produced in bone marrow.
Iron is required to produce hemoglobin necessary for RBC production. 1 to 4 mg of iron/day is the minimum required.

Elements of Blood
Normal healthy blood contains around 5 million RBC in each cubic millimeter.
Hemoglobin:
It is a large molecule.
It associates with O2: red color
It associates with CO2: bluish purple color

Elements of Blood
Leukocytes:
White blood cells.
4000 to 11000 leukocytes.
1 leukocyte for 500 RBC.
There are two categories:
Phagocytes: spend their time eating foreign bodies.
Immunocytes: involved in the immune response of the body.

Elements of Blood
Thrombocytes:
Platlets.
Normal lifespan 7 to 10 days. 250 000 platlets/ ml3
Their role is to form a mechanical plug during normal hemostatic response to vascular injuries.

Elements of Blood
Plasma:
Around 92% water by volume.
Contains: sodium ions, potassium, calcium, … (1%).
7% plasma proteins.