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Forgotten Organs

Karina G's picture
It is curious to know that a human adult is made of 206 bones yet we don’t pay much attention to them. Bones are made up by tissues on the inside an outside of its structure. Each tissue accomplishes different functions that are vital for the human anatomy. Also they provide the structure of the human body, without them we would be gelatinous. Bones do not only support our body and protect some organs but also produce red and white blood cells and store minerals. In fact bones are organs. In this essay we will study the internal and external makeup of human bones and why does osteoporosis happen.
Some of the tissues found in bones are osseous tissue, marrow, endosteum, periosteum, nerves, cartilages and blood vessels. The outside of bones is formed by osseous tissue also called bone tissue. There are two types of bone tissue: compact and spongy or trabecular bone. The compact bone is found in the exterior and it accounts for 80% of total bone mass in an adult. Meanwhile the trabecular bone occupies the interior and accounts for the remaining 20%. “The tissues are biologically identical; the difference is in how the microstructure is arranged.” (Wikipedia 2) Their difference in arrangement provides them with differing characteristics, hard and soft. We have learned in class that the assembly of molecules can be accounted for the features of an organism. Osseous tissue provides protection of vital organs such as the heart. Also it supports soft tissues, muscles and organs and facilitates movement and provides force. Another function is that it stores calcium phosphate, which is the conjunction of minerals. In large parts tooth enamel and 70 % of bone is made up of a calcium phosphate mineral. There lies the importance of calcium intake.
            Another tissue of key importance is marrow. Marrow is a flexible tissue found in the hollow interior of bones. This produces new blood cells in large bones and it represents 4% of total body weight in adults. This tissue is also constituted by two types: red and yellow marrow. When we are born all bone marrow is red, as we age it turns yellow. When the body needs to increase its blood cell production (due to a disease) this process is reversed, it goes from yellow back to red. This is pretty interesting! In red marrow come up platelets, red blood cells and most white blood cells. Also this tissue consists of myeloid tissue; which performs hematopoiesis. This process is the formation of blood cellular components. Moreover yellow marrow consists of fat cells. As we may have discussed in class fat cells store energy and insulate and cushion our body. Bone marrow has its own system to make everything work together to accomplish its many functions. One key player is the blood vessels which create a barrier to impede immature blood cells from leaving the bone marrow. “Only mature blood cells contain membrane proteins required to attach to pass the blood vessel endothelium.” (Wikipedia). This is an example of how our body is like a spider web in which molecules interact and come together to accomplish a task and how this task is related to the work other molecules or cells are doing. Everything within the human body is interrelated.
            Who would have thought that bones in our bodies are constantly undergoing change? I always thought of bones as hard and inanimate. However, Bones are storing and releasing calcium and other substances. Also our bones undergo a change called bone remodeling.  “Bone is continuously changing- new bone is made and old bone is broken down- a process called remodeling, or bone turnover.” (Mayo Clinic) From the moment you are born you accumulate bone mass. When we are young the ratio of bone breakdown is lower than the creation of new bone mass. That is why you accumulate a lot of bone mass in your early age. “You reach you’re your peak bone mass in your mid-30’s.” (Mayo Clinic) Once you reach a maximum bone mass as your bones continue undergoing remodeling, the ratio of bone break down increases at the point where more bone is broken down than is created. As we age bones may weaken due to low levels of calcium, phosphorus and minerals. The lack of these compounds produces osteoporosis which means “porous bones”. Basically before your mid thirties you accumulate calcium and bone tissue and depending on how much you have stored you can develop osteoporosis. When you have osteoporosis your bones are likely to break or fracture with a simple everyday movement like bending your knees or lifting an object. Fractures are more likely to occur on wrists, hip or spine. Nonetheless any bone can suffer a fracture. This is a serious disease that is treatable but the fractures are painful. Not a lot of people pay attention to their calcium consumption because they don’t see bones as another organ that needs to be taken care of. In this essay we learned the importance of our bones and their fragility. Hopefully everyone starts drinking milk because there is still time.
·         Mayo Foundation for Medical Education and Research. 2009. Web <> 4 December, 2009

·         “Bone” Wikipedia. 2009. Web <> 3 December, 2009 


Paul Grobstein's picture

oh dem bones

Maybe we'd be better off, like arthropods, with an exoskeleton?  Or perhaps, like coelenterates, without a skeleton at all?