is a hard specialized connective tissue that provides structure and strength similar to that of bone.
cells, called chondrocytes secrete a gel-like substance and fibers that form a flexible matrix similar to that of the bone,
and arrange themselves in chambers within the matrix called lacunae. This results in a tissue that is very flexible and very
tough, but not as dense as bone, and not very stretchy.
while very useful, is not found in too many places in the body, and comes in three distinct forms.
abundant form of cartilage is hyaline cartilage, which is made of tiny collagen fibers, and is most present at the end of
the long bones in the body, in order to cushion the joints where bones meet. This prevents abrasive wear and tear of the long
bones, and allows the bones to slide along each other within the joints without any discomfort. This type of cartilage has
a rubbery texture, and is of a bluish-gray hue.
cartilage is also the main constituent of the fetal skeleton, and as the fetus grows and develops, this cartilage skeleton
is covered by and replaced by a matrix of bone. The osteoblasts, which form the bone, continue to grow over and digest the
cartilage until a hard bone skeleton is all that remains. This process is called ossification.
cartilage is also found in the rings that support the trachea and major bronchioles of the lungs, working to keep them open
during respiration. It is also found in the nose, the larynx, and connects the ribs to the breastbone to form the ribcage.
type of cartilage is elastic cartilage, and is made up of elastic fibers. It forms the pinna of the ear, and provides flexibility.
the last type of cartilage, fibrocartilage, is also composed of collagen fibers, and serves as a shock absorber between the
vertebrae of the spinal column and in the joints of the knees.