This brief video provides a histological overview of the intervertebral disc (IVD), defining its composition and structure. The IVD, situated between vertebral bodies, is classified as fibrocartilage, which is microscopically characterized by dense collagen fibers and scattered chondrocytes housed within lacunae. The video highlights the two functional regions of the disc essential for cushioning: the central, softer, and water-rich nucleus pulposus, and the surrounding, dense, fibrous ring known as the annulus fibrosus.
Histology of the Intervertebral Disc (IVD)
0:07 The Intervertebral Disc: The IVD is located between two vertebral bodies (membranous bone).
0:29 Definition of Material: The IVD is composed of fibrocartilage, which is typically found where bone touches bone.
0:35 Other Locations for Fibrocartilage: Common locations include the pubic symphysis and the menisci of the temporomandibular joint (TMJ) and the knees.
0:51 Microscopic Identification: Fibrocartilage visually resembles dense fibrous connective tissue (containing many collagenous fibers) but is distinguished by the presence of small chondrocytes residing within lacunae.
1:41 Structural Differentiation: The IVD is designed for cushioning, featuring a softer, more gelatinous interior and a denser, more fibrous exterior.
1:57 The Nucleus Pulposus: The looser, water-rich, central area of the IVD is called the nucleus pulposus.
2:05 The Annulus Fibrosus: The dense, fibrous, ring-like periphery of the IVD is called the annulus fibrosus.
Key Takeaway: Both the nucleus pulposus and the annulus fibrosus are composed of fibrocartilage and together constitute the intervertebral disc.