Bone Marrow

Bone Marrow
Bone marrow is an integral part in the life of a human being and it functions as the stemming up region for many of the blood cells including the red blood cells which carry oxygen from lungs to the other tissues. Furthermore, as it involves in the production of white blood cells, which directly involves with the persons immunity, bone marrow failure can lead to poor immune response and to an increased susceptibility towards infections. Because of these reasons, the bone marrow failure would be detrimental to human life and it may even lead to fatal outcomes when there is no other way to compensate.

Bone marrow would contain precursor cells from which all other types of cells stem out and would also consist of many of the precursor cells that it had already produced. Apart from these two, the marrow would also consist of matrix cells as well as fat cells to a certain extent. In a healthy person, the marrow would account for about 4% of the body weight and it can be classified into red and yellow bone marrow according to its location, color as well as from the cells that are present in abundance.

The red marrow:
This is the main marrow that gives rise to all the red blood cells, white blood cells as well as to the platelets and are located in the flat bones such as hip bones, skull bone, ribs, breast bone and the vertebra. During the fetal life and in the early childhood many of the long bones would also contain red marrows although they become ossified and replaced within few years. But, the left over red marrow will prevail throughout life according to the requirement of the human body and would continue to function even when a person reaches the elderly stage. In certain instances, many diseases including cancers, infections as well as inflammatory conditions can affect the bone marrow and at times, certain medical treatments such as radiation can also affect the marrows.

The yellow marrow:
Being located in the hollow centers of the long bones such as in the legs and in the arms, yellow marrow largely consists of fat cells although it will have a different role to that of normal fat cells. Although the initial bone marrow present in a newborn would be of the red marrow variety, it will be converted into yellow marrow at desired locations by the age of 5 years. Basically, these fat cells are the last resort for body’s energy requirements and can be consumed in an event of extreme hunger. But, the important function that is perform in relation to formation of cellular elements is its ability to convert itself into red marrow in case of large volume blood losses which would deprive the body of oxygen carrying capacity in certain instances. The yellow marrow, being so efficient, would be able to convert itself within 1 – 2 hours to take over the role of a red marrow and this is one of the natural reserves to sustain life in extreme events.

Know more:
http://www.preservearticles.com/201101133203/difference-between-red-bone-marrow-and-yellow-bone-marrow.html
Source:
http://www.sciences360.com/index.php/anatomy-physiology-173-8391/

Image: A femoral head with a cortex of cortical bone and medulla of trabecular bone. Both red bone marrow and a focus of yellow bone marrow are visible/ Wikimedia Commons