Questions to Consider

While you are reading keep some of these questions under consideration. After you are done reading this blog you can scroll back up again and try to answer these questions based on your acquired knowledge:

1. List at least two major functions of our bones?
2. What are joints?
3. What are the end of bones covered with?
4. What type of joint is found in your shoulders and hips?
5. Name each type of joint and which part of the body has that joint?
6. What are osteoblasts and osteoclasts?
7. Label this diagram of the parts of the bone..

A.                                           
B.                                           
C.                                           
D.                                           
E.                                           

Functions of Your Skeletal System

The skeletal system contains all of our bones in our body. Theirs five major functions of the skeletal system are:

• The skeleton gives shape and support to our body.
• The bones protect our internal organs.
• Most muscles are attached to bones and helps them to move.
• The blood cells form in red marrow in many bones.
• Calcium and phosphorus makes our bones hard.

Bone Structure

This image is the bone structure looked at from the inside and from the outside.
As you can see the parts are labeled, and you can follow with the paragraph.

       Bones have bumps, edges, round ends, rough spots and holes. The holes in the bones are helpful because they help the blood vessels and the nerves to enter into them.

Bone Tissue      Even though it's unbelievable, a bone is actually an organ! The living bone is made out of several different tissues and thus makes it an organ. The living bone's outer layer is covered with periosteum which is a tough and tightening membrane. The compact bone of the bone is the part of the bone which makes the bone stringer or harder. This strength is due to the deposits of calcium phosphate in the framework of the compact bone. In the center of the bone there are cavities which are filled by the spongy bone which contains marrow. There are two types of marrow cells, first, there are blood cells which are red and, second, there are fat cells which are yellow.

Cartilage
       Cartilages are tissues that cover the end of bones so that when two or more bones are near each other they won't rub against each other. Therefore this part of a bone must be slippery and smooth and this way it makes it easier for less friction to be produced. The cartilages are flexible and it helps the joints because it acts as s hock absorber and makes the job of the joints easier.

Bone Formation

       Just like any part of your body, before we were born they had to develop. This is what happened our bones. The bones just didn't appear out of the blue, they had to form and develop. Before we were born, our bones in our skeleton were made completely out of cartilage. Throughout time, the cartilage was broken down and replaced by actual bone. In order for this newly formed bone to get stronger, bone forming cells called osteoblast (AHS tee oh blasts) have to deposit calcium and phosphorus.

      A healthy bone is always being formed and being reformed. In order for the bone to be reformed, something has to break down it. This is the job of osteoclasts  When these osteoclasts brake down, they release calcium and phosphorus. Then the cycle continues.

Joints

     Everything that we do is possible because of joints we have in our skeleton. A joint is any place in which two or more bones join together. These bones don't hold in place magically, instead all the bones are held tight by a tough band of tissue named ligament. Some bones have a thin layer of cartilage in between them therefore preventing them to rub against each other.

     A common joint problem is arthritis. The word arthritis isn't specifically a disease, but is a term used to describe more than 100 different diseases in the joints. Some of the symptoms of arthritis are but are not limited to: pain, stiffness, and swelling of the joints.

     There are two different joints in our body. The immovable joints and the movable joints.

Immovable Joints

• An immovable joint is a joint which permits small or no movement at all.
• An example is the joints in our skull and pelvis.

Movable Joints

    Movable joints allow movement in our body. The four types of movable joints are pivot, ball-and-socket, hinge, and gliding.

• A pivot joint, as shown in the image in the right, is when one bone rotates in a ring of another bone that does no movement. For example, turning our heads.

• A ball-and-socket produces a wider range of motion possible. It can move in almost 360 degrees. As show in the image to the right, our shoulder is an example of this joint because it can move in many directions.

 

• A hinge joint is a joint that allows a back and forth movement. An example of these movements are elbow, knee, and finger joints. As shown in the image to the right, limited movement is allowed like in a real life elbow.

• Another type of joint is a gliding joint, which one bone slides over another part of another bone. This is the type of joint that is mostly used in our bodies. This joints are kid of the same like hinge joints but the difference is that the bones aren't beside each other, the bones are moving on top of each other.

Moving Smoothly

     Lets say you are writing in a chalk board with a chalk. Eventually, the chalk wears away. Fortunately for our bones, they have cartilages. These cartilages help movement in the joint easier.  If the joints didn't exist our bones would wear away just like chalk does when being used.