Roles of iron in blood system

About 6 percent of body iron is a component of certain proteins, essential for respiration and energy metabolism, and as a component of enzymes involved in the synthesis of collagen and some neurotransmitters.

Perhaps the most important of iron’s functions in the body is the production of hemoglobin and myoglobin (the form of hemoglobin found in muscle tissue), and the oxygenation of red blood cells. Myoglobin takes oxygen from hemoglobin and delivers it to muscle cells, and the cytochromes, which are important for generating energy.

Iron complexed with the protein hemoglobin is necessary for oxygen transport in the blood. Iron is the central atom of the heme group, a metal complex that binds molecular oxygen (O2) in the lungs and carries it to all of the other cells in the body that need oxygen to perform their activities.

Iron is the mineral found in the largest amounts in the blood. About 25 percent of the iron in the body is stored within enterocyte in the form of ferritin, circulates in the blood. Ferritin is made up of heavy and light chain subunits, which create a spherical hollow space that can accommodate up to 4500 iron ions.

The average adult male has about 1,000 mg of stored iron (enough for about three years), whereas women on average have only about 300 mg (enough for about six months).

Ferritin can release iron if the blood has a low iron concentration, and it can help to store excess iron if the blood and tissues have a high iron concentration. Hence, ferritin functions as a "buffer" against iron deficiency and, to a lesser extent, against iron overload.

When iron stores are exhausted, the condition is called iron depletion. Further decreases may be called iron-deficient erythropoiesis and still further decreases produce iron deficiency anemia.
Roles of iron in blood system

Anemia due to protein deficiency

Anemia is a reduction of hemoglobin in red blood cells below normal levels.

Patients with protein deficiency anemia also show signs of multiple nutritional deficiencies, especially of folic acid, vitamin B12, and iron.

Protein is essential for the proper production of hemoglobin and red blood cells. Due to deficiency of proteins, the synthesis of hemoglobin is reduced. The RBCs are macrocytic and hypochromic.

The deficiency protein results in decreased formation of all hematopoietic cells. Hematopoietic cells are lodged within the bone marrow that give rise to all the other blood cells and are derived from mesoderm.

A mild normocytic anemia develops after 6 months of semi-starvation and after 3 months of complete starvation.

In chronic protein deficiency, the decreased RBC production is proportionate to the reduced by decreased secretion of erythroproietin.
Anemia due to protein deficiency

Calcium in blood clot system

Calcium is an essential body mineral. Approximately 99% of the calcium in the body is stored in the bones. The rest is located in the blood and tissue fluids.

Calcium is necessary for blood clotting. Calcium is essential for the formation fibrin, the fibrous proteins that makes up the structure of blood clot.

According to Best and Taylor’s theory: when blood is shed form wound, thromboplastin is liberated from the damaged tissue and disintegrated platelets. It acts on prothrombin in the presence of calcium and coverts it to active thrombin. Then thrombin reacts with fibrinogen and converts it into fibrin, which is insoluble. 

Calcium actually participates in nearly every step of the blood clotting cascade. Adequate amounts of calcium ions are required in all phases of blood clotting and blood will not clot in the absence of calcium.

The constants level of calcium in the blood and tissues is maintained by the action of calcitonin and parathormone.
Calcium in blood clot system