Skeletal system: Difference between revisions

The spongy bone is where all of the blood cells are created from the bone marrow. Spongy bone contains two different types of bone marrow: red and yellow marrow. The red bone marrow produces red and white blood cells and platelets. The yellow bone marrow, however, is used to store fats.[http://webschoolsolutions.com/patts/systems/skeleton.htm]

Cartilage is a tough, elastic, and flexible [[connective tissue]]. The ground substance of cartilage is composed primarily of chondroitin. Its extracellular material is produced by chondrocytes, or mature cartilage cells. These cells are too large to directly inhabit the matrix. Instead, they reside in hollow spaces in the ground substance called lacuna. Another unusual characteristic of cartilage in comparison to other connective tissues is it is avascular, meaning that it lacks blood vessels. This is an issue because the chondrocytes are still living cells and require oxygen and other nutrients to function. Therefore, the elements necessary for the cells' survival must diffuse through the matrix. For this reason, the extracellular matrix cannot be very thick. Regardless, cartilage is very strong and durable to withstand arduous circumstances.