Fibrocartilage is a specialized type of cartilage found in only a few specific regions of the body: intervertebral discs, menisci of joints (like the knee joint) and the symphysis pubis of the pelvis. It is made by cartilage cells called chondrocytes (the cats pupils) that reside in lacunae (the cats eyes).
Hyaline cartilage is the more common type of cartilage in the body. Its cells synthesize cartilage that contains very fine Type II collage fibers that are not good at resisting tensile forces (regular cartilage can tear easily under this force) but creates lots of space that is occupied by loads of water making - it ideal for resisting compressive forces (you can’t easily compress water right!)
Fibrocartilage is different. It is impregnated with a a type of collagen more commonly found in strong tendons and ligaments - Type I collagen (the red/pink material that fills this image). This means that fibrocartilage is adapted to resist some compressive forces but also strong tensile forces. In other words it’s not quite cartilage and its not quite a ligament/tendon.
It’s an ideal tissue to sandwich between adjacent vertebra in the vertebral column (an intervertebral disc) where it forms the outer wall of the disc (annulus fibrosus). Here it is responsible for resisting the compressive and tensile forces generated when our vertebra try to move apart and together as we flex our spines during everyday movement.
barefootdressage, I just ran across this image on a somewhat unrelated quest to yours and thought you might find it helpful. I don’t think the last post clearly pointed out these joints. Or if it did, I can’t remember it. [ Or maybe it’s all just starting to blur together in my mind. Haha! ;) ]
This is a transverse slice through the lower part of your leg.
Trollface’s eyes are formed from the two bones in the lower leg - the tibia (larger) and fibula (smaller). You can see the bright pink spongy bone trabeculae that form the core of each bone and the purple connective tissue periosteum encircling each eye!
The rest of old Trollface is made up of skeletal muscle. Each muscle group is organized into fascicles and in turn groups of fascicles are organized into muscles that are subsequently grouped into compartments by connective tissue encircling collections of muscle fibers. The connective tissue responsible for this compartmentalization appears purple and has formed the outline of the nose, mouth and chin. A superficial fascia also surrounds the entire limb encircling all the muscles toward the periphery.
Finally, the very outer aspect of Trollface is his skin. It is also the skin that surrounds your leg. You can make out some tiny purple dots in the dermis which are the hairs and hair follicles that have been sectioned.
Trollface himself is a rage comic character created by Carlos Ramirez and posted to the internets. He represents the smugness of an internet troll. His original character was reposted all over the internet and is now legendary among internet memes.