Practical Application of Primary and Secondary Sites of Ossification

Practical Application of Primary and Secondary Sites of Ossification:




During bone development there are are primary and secondary centers of ossification. In between these two sites of bone development there will be cartilage while the bone is still growing. When the primary and secondary centers of ossification, the cartilage will be gone and the bone will stop growing.

This concept in developmental biology lets us look at an X-Ray to see if a person is still getting taller. If there is cartilage in between the primary and secondary centers of ossification then the bone is still growing and the person will get taller.

Below is an X-Ray of a person that is still growing and you can see the bark band of cartilage between the primary and secondary centers of ossification.


Below is a X-Ray of a person who has reached full height. There is no cartilage present in the bone and the primary and secondary centers of ossification have grown together.

Practical Application of Tonocity

Practical Application of Tonocity:

Tonicity is a measure of the water pressure between inside and outside of a cell. The water pressure is created when there are two different solution concentrations inside and outside of the cell.

If there is exactly the same concentration inside and outside the cell there will be no movement of water. However, if the concentration is higher inside the cell (as it is in a hypotonic solution), water will want to move into the cell by the process of osmosis. I this situation the cell will fill with water and eventually explode.

This concept has practical application because it is why patients are given 0.9% saline solution when they receive an IV in the hospital. This is the concentration the solution needs to be because in order to have the concentration inside and outside the cell be the same.

If you accidentally gave a patient a IV drip that was distilled water you would create a hypotonic solution and the patients red blood cells would explode and die.

In this blog we will discuss practice ("real-world") applications of the material we are learning in Introduction to Anatomy and Physiology.