Histology and Structure of Cartilage and PBL

We had a brief histology seminar this morning about cartilage. Again, the cartilage cells and extracellular matrix organization tends to parallel the organization for bone, so it's not terribly hard to understand the cartilage structures after having learned the bone ones last week. One difference though is that bone and cartilage contain different types of collagen in the extracellular matrix, and of course cartilage is not calcified (at least not normally!) like bone is. The second part of the seminar covered the structure of collagen molecules. Cartilage is almost all extracellular matrix, and a large portion of that extracellular matrix is collagen. It's a pretty interesting molecule. A collagen molecule gets synthesized inside a cell called a chondroblast as a precursor with extra pieces on the two ends. These pieces are needed to keep the collagen molecules from polymerizing inside the cell and to direct the assembly of the collagen, but they get cleaved off later.

Our PBL case isn't particularly interesting this week, but it has about a zillion parts. We also have a ton of learning objectives for Friday. That's ok though, because there really isn't any case left for Friday. We're making our presentations ten minutes this time instead of just five. My learning objective is on the anatomy of the knee. This will force me to finish reading the anatomy book section about the knees, so that's a good thing. I'm meeting with my preceptor for the clinical research project I'll be doing this summer in a little while, so I am off to finish reading the proposal draft.