intercellular-substance

False-colored scanning electron micrograph of collagen/connective tissue removed from human knee during arthroscopic surgery. Courtesy of Wellcome Images.

The glove connection

For San Diego Padres fans, the news Sunday was worse than just another loss, the ninth in a row.

During a game against the Washington Nationals, the Padres’ promising, young catcher Yasmani Grandal was seriously injured in a play at home plate.

The early diagnosis: Likely tears to both the anterior cruciate ligament and the medial collateral ligament in his right knee.

If that’s the case, Grandal will be done with baseball this year and may not play again until deep into the 2014 season. Depending upon its severity, the injury could be career-ending.

For those wondering why it might take a healthy, strapping (6-foot-2-inches, 215 pounds) 25-year-old  so long to recover (after surgery), take a look at the image above: That’s a strip of “simple” connective tissue from a human knee. There’s nothing really simple about it.

Connective tissue is the most widespread and abundant type of tissue in the human body.  Its function is primarily to support, anchor and connect various organs and parts of the body.  Though it exists in multiple forms – the connective tissue of the knee is obviously different than the connective tissue supporting the eyeball – all connective tissue boasts three common ingredients: cells, fibers and a material called intercellular substance

The most common cell type is fibroblasts, which make up fibers. The most common fiber types are collagen and elastic. Collagen fibers provide strength; elastic fibers provide, well, stretch. Both fibroblasts and fibers are embedded in the intercellular substance, which has a consistency ranging from gelatin-like to quite rigid.

The recipe for connective tissue varies with the particular nature and demands of its job. Strong connective tissue, like that needed in tendons and ligaments, features more collagen fibers and fewer cells. Conversely, adipose connective tissue (otherwise known as body fat) consists primarily of cells since it’s not really required to do much other than just sit around, which, unfortunately, is probably what Grandal will be doing for quite a while too.