Monday, May 9, 2011

Introduction To The Human Skeleton part 3

One wouldn't think it, but bones are also a storage medium. Our bones are not only made up of calcium, but also store it for use in the body. As mentioned before the bones are the storage container for bone marrow. Our bodies need calcium to complete daily functions properly and the place where we store that calcium is in our bones. Another vital mineral that is stored in the bones is iron. This is stored in the bone marrow of bones. This plays a vital role in our bodies. For red blood cells to work properly they must have iron. Without the iron our red blood cells would not be able to transport oxygen properly in the body, so having a place to store it is very important.


Our bones are also responsible for the regulation of certain hormones in our bodies. This particular hormone is called osteocalcin. This hormone is responsible for the regulation of the sugar in our blood and the depositing of fats. Without our bones producing this hormone our body would not be able to create the things needed to help aid in the digestion of our foods.

  

The male and female gender in humans have a few differences in the shape of some bones. Females slightly different shaped hips to help accommodate child birth. They also tend to have rounder shapes to most of their bones where as men with have more angular features than women. Also most bones in females are must smaller than those in men. The average height of men in the U.S is 5 feet 9 ½ inches where as the average female is 5 feet 4 inches.


Introduction To The Human Skeleton part 2

An extremely vital role that our skeletons do is provide protection. All of our vital organs are contained within the body cavity. Our rib cage, spine, and sternum create a cavity that houses and protects our lungs, heart, and some of the biggest blood vessels in our bodies. One of the most vital pieces to a functioning human is protected by our skulls. The human brain sits inside the skull suspended in a fluid. Along with the brain, our eyes also housed and protected by our skull. The spine and hip bone provide an area for the intestinal track to lie in while providing some protection for it. There are also a few bones that actually provide protection for other bones. The knee cap protects our knees when we bang them into things. Without the knee cap impacts would hit directly on the joint portion of the leg bones leading to bad injuries. Another example is the ulna bone. It provides protection for the elbow just as the knee cap does for the knee.


Our bones are also responsible for the production of our blood. The process of making blood is called haematopoiesis. The blood cells are created inside of our bones in an area called bone marrow. Our bone marrow is equal to about 4% of out total body weight. There are two types of marrow, yellow and red. Blood cell creation takes place in the red marrow. When we're first born all of our marrow is red but slowly some of it turns to yellow. A very neat thing our bodies can do in a time where our bodies suffer extreme blood loss it can turn yellow marrow back to red to help aid in blood production. Red marrow is mainly found in flat bones. Our hip, breast, cranium, ribs, vertebrae, and shoulder blades are major areas of blood cell production. Other areas where it is found is found at the ends of most other bones, especially the long bones found in our arms and legs. Another vital role that happens in the bone marrow is the creation of lymphocytes. These play a vital role in our immune system to help keep us strong and healthy.


Sunday, May 8, 2011

Introduction To The Human Skeleton part 1

Our skeletal system has some very important functions. These functions can be broken up into six different categories; support, movement, protection, blood production, storage, hormone regulation. Our bones are the main thing that holds a person up. Bones by themselves cannot stand up, but the bones are needed as a framework for muscles, tendons, and ligaments to attach to. Similar to how a house is built. You must have the frame built to attach everything else in the house. Without our bones humans would be blobs.

 
Our bones are extremely important for our movement. The places where our bones meet are known as joints. Some joints are movable, like the ones in our arms and legs. There are others that are not moveable such as our ribs where they meet the sternum. There are several types moving joints. The ball and socket joint can be found in the legs where they attach to the hip as well as in the arms at the shoulder. This type of joints allows for a further range of motion. Gliding joints can be found in our wrists. As the name suggests they allow for a gliding motion between bones. The joint that allows our elbows to move is known as the hinge joint. This joint allows movement in only one direction. The joint that allows us movement at the knee is called the compound joint. Like the pivot joint it allows for rotation only in one direction. These joints are all a type of synovial joint. This type of joint has fibers known as ligaments that attach the two bones together. Inside the joint is a lubricating fluid and cartilage to allow for smooth movement in the joint. 

The actual movement of our bones is done by the muscles in our bodies. Fibers known as tendons attach the muscles to the bones. When the muscles contract they pull on the tendons which in turn pulls on the bones. Having muscles and tendons on both sides of a movable joint in our bodies allows for muscles to move back and forth allowing us to move about.