(C24 - 27) Slide 58: Spinal Column, H&E

There are two parts to an intervertebral disc; the outer annulus fibrosis composed of fibrocartilage and an inner nucleus pulposus. We will concentrate on the fibrocartilage of the annulus fibrosis. The arrows in C24 show the two locations of fibrocartilage that we will study today.

There is a lot of material on this slide and one can get lost easily when searching for fibrocartilage. So, to find the two fibrocartilage types, locate the ventral horn of the spinal cord (C24, SC) at low magnification. Just ventral to the spinal cord is a region of CT, which we will avoid, but ventral to that, is the intervertebral disc (C24, d). On the outside of the disc you will see a layer of fibrocartilage. Here, it is an intermediate tissue connecting a tendon to the hyaline cartilage, which is associated with the bone of the vertebral column (C25). The chondrocytes are arranged in a linear pattern between the dense collagen bundles (C26). Notice the lacunae. This tissue resembles that of the tendon. Follow the tendon until it blends into the fibrocartilage which, if followed further, will mesh with the hyaline cartilage and then bone. Don’t expect to see an abrupt change between these tissue types because there is not one. Caution not all slides show this well.

The third arrangement of fibrocartilage is located on the other side of the disc. If you are having difficulties finding the fibrocartilage in this region, do the following; first, go back to C24 and see if you are on the right area of the slide. If that doesn’t help, maybe there isn’t any on your slide so, either get an instructor to verify this, or get another slide. Once you have found it, notice the "herringbone" arrangement of the dense collagen bundles and the chondrocytes (C27). These fibers are organized to withstand stresses in more than one direction.

WHEN ASKED TO NAME FIBROCARTILAGE ON AN EXAMINATION, SIMPLY SAY FIBROCARTILAGE. YOU DO NOT HAVE TO INDICATE ITS ARRANGEMENT.