Skeletal System

The lesson that ill be going to discuss is all about skeletal system. When we hear skeletal system we usually think about bones. Do you? Cause I do. Just so you know skeletal system is the framework of human body, it produces blood cells, provides protection to our organs, helps us to breathe, stores minerals, and allows movement along with muscular system.

Skeletal system’s primary components are bones. Bones are composed of non-living minerals such as calcium. There are different classifications of bones: long bones which can be found in arms and legs, short bones which can be found in wrists and ankles, flat bones which can be found in the skull, ribs, and breast bone, and Irregular bones which can be found in the hip and vertebrae that makes up the spine.

There are also different parts of a bone. Periosteum which covers the bone, Epiphysis which is each bone end, Diaphysis which is the region between the ends, medullar cavity which is a hollow region that acts as a storage area for bone marrow, and bone marrow which has two types: yellow which has a high fat content and red which is in charge for production of red blood cells.

There are different types of bone tissues: compact and spongy or cancellous tissues. Compact tissue is a dense hard tissue that is composes of shafts of long bones and outer layer of bones. Spongy or cancellous tissue which is arrange in bars and plates called trabeculae, it is also lined with endosteum-a tissue similar to periosteum, it helps to make the bones lighter in weight.

Bones have a projection which is the points of attachment, bumps and depressions which are the pathways for nerves and blood vessels.

Wonder how bones are formed? Bones are formed through Ossification. Bone grows longitudinally in order to develop height and horizontally so they can more efficiently support body weight. There are different cells involved in ossification. Osteoprogenitor cells are non-specialized cells found in periosteum, endosteum and central canal. Oeseoblasts are cells that actually form bones. Osteocytes are the mature cells. Lastly, Osteoclasts originated form a type of white cell called monoocyte that is found in red bone marrow. Intramembraneous ossification occurs when bone develops between two sheets compose of fibrous connective tissue. Endochondral ossification occurs when shaped cartilage is replaced by bone.

Cartilage is a special form of connective tissue that can withstand a fair amount of flexing, tension and pressure. These are the ones which makes a flexible connection between bones, it acts as a cushion between the bones Articular cartilage acts as a shock absorber it is located at the ends of the bones. Bursa is a small sack that contains a synovial fluid.

When two or more bones are joined together they are called Joints. Joints are classified into two: function and structure. Classification of bones according to function are immobile, slightly movable, and freely moving. While according to structure are fibrous, cartillagenous, and synovial joint.

Actually, we had this discussed only for an hour. So it was hard for me to comprehend it well because the reporter should make the discussion fast because she’ll run out of time. The reporter only had a one hour limit to report. It was really hard to be familiar with the discussion for a short period of time. I’d say it is “boring” because the reporter was only reading her slides, (it was 40+ slides I guess >.>) even though I appreciated her effort. If the reporter made it short and used simple graphs I would possibly enjoyed her discussion. I liked it when our professor gave us an activity in which we have to make a skeleton dance. The whole class participated in this activity and so it was fun like everyone was laughing at each others faces and the way they dance. It is good to have an activity like this after a long discussion. Well, professors really do know how to make his students look stupid in front of the class.