In this video, we're going to talk about the first type of cartilage in our lesson, which is hyaline cartilage. Hyaline cartilage is actually the most abundant cartilage throughout the entire human body and is also the weakest form of cartilage among the 3 different types of cartilage. Now hyaline cartilage is actually named for its appearance in the human body, appearing as bluish white color with a very smooth, glassy type of appearance that can actually have some shine to it.
The root "hyal" in hyaline cartilage is a root that means glass. Hopefully, this can remind you of hyaline cartilage's very smooth and glassy type of appearance. In terms of its composition, hyaline cartilage has very small, fine, or thin bundles of collagen fibers in its extracellular matrix. We know that these collagen fibers are long, unbranched, and straight fibers that give the tissues lots of strength and a little bit of flexibility, making hyaline cartilage a very tough connective tissue.
However, because these collagen fibers are arranged in very small, fine, or thin bundles, this is what makes hyaline cartilage the weakest form of cartilage among the 3 different types of cartilages. In terms of its function, because hyaline cartilage has this smooth, glassy type of appearance, that smooth nature actually helps to reduce friction between bones. Like all cartilages, which are very tough connective tissues with some flexibility as well, hyaline cartilage serves as a very strong and flexible structural support. Notably, hyaline cartilage serves as the precursor to bone in the fetus, and human embryos have skeletons made almost entirely of hyaline cartilage initially.
As the human develops, that hyaline cartilage is slowly replaced with bone. In terms of the body locations where we can expect to find hyaline cartilage, it serves as a strong and flexible structural support in body locations such as the nose, the larynx or the voice box, and the trachea or the windpipe. It is also found at the ends of long bones where it helps to reduce friction between the bones. This can be found in areas such as our knee, elbow, and shoulder.
Hyaline cartilage is also associated with developing bones as well because it is the precursor to bone in the fetus. It makes up most of the skeleton of the human embryo and is slowly replaced with bone as the human develops. Hyaline cartilage is found in the nose, helping to give our nose its structure and shape. It is found in the larynx and the windpipe where it helps to prevent the collapse of the windpipe and still allows for some flexibility for the expansion and contraction as we breathe.
It is also found connecting the bones of our ribs to the sternum or our chest bone, where it can give our ribs some flexibility as it expands and contracts during breathing. It can also be found in joints at the ends of long bones where it reduces friction between bones. We have a micrograph of hyaline cartilage, highlighting a chondrocyte within the lacunae. Recall that the lacunae are chambers in the extracellular matrix that house the chondrocytes, which are the mature cells of cartilage.
The matrix is a firm yet flexible and rubbery extracellular matrix, and most types of hyaline cartilage are surrounded by the perichondrium, a layer of dense irregular connective tissue that is vascular and can help to support the hyaline cartilage by providing nutrients through its blood vessels. Like all cartilages, hyaline cartilage is avascular, and not all hyaline cartilage has the perichondrium. For example, the cartilage at the ends of long bones, sometimes referred to as articular cartilage, does not have a perichondrium mainly because it needs the cartilage to be available to reduce the friction between bones. This here concludes our lesson on hyaline cartilage, and we'll be able to apply these concepts and learn about other types of cartilages as we move forward in our course. So I'll see you all in our next video.
