 So, this is a quick demonstration of the lumber vertebrae. Let us take a quick look at the parts. We can see that this is a huge structure in the front. This is the vertebral body. The lumber vertebrae is for the largest body because it is weight-bearing and that is one of its main functions weight-bearing. This is the vertebral foremen and this when all the vertebrae are united together it forms a vertebral canal which gives passage to the spinal cord. And the posterior portion of the vertebral foremen this whole thing composite mass is called the vertebral arch. The vertebral arch has got certain special processes one is the central one that is known as the spinous process. This is formed by the fusion of the two laminate to form the spinous process. Then we have these two lateral projections called the transverse processes. And we have this projection going up and down these are the superior and inferior articular facets also called the zygopophysics. The small space in between the superior and inferior this region is referred to as the parse interarticularis. Take a look at the articular facets the superior one. If you look at the articular the direction of the facets they are in the sagittal plane. This is in contrast to the articular facet of the thoracic vertebrae which was in a coronal plane. So, this sagittal articular facets allow the flexion and extension mobility of the lumbar spine. And that is the reason why the t12 the upper facet is in the coronal plane the lower facet is in the sagittal plane because the t12 has to articulate with l1 below. Okay so this is the significance of the articular facet and the mobility. The portion which attaches the patch to the vertebral body this referred to as the pedic. This peripheral portion of the body is made of vertical bone and that is known as the epifysiol rib. It is derived from the annular epiphysis. And the central larger portion is the spongy bone which is derived from the central. So, these are the salient parts of a typical vertebrae and a lumbar vertebrae. Let us take a look at some of the critical correlations pertaining to the lumbar vertebrae because it is weight bearing it is subjected to maximal stresses and strains. In old age especially in females this can undergo osteoporosis or osteopenia and it can lead to compression or wedge compression fracture. Spontaneous it can happen. New bone formation can take place at the articular facets and the margins and that is known as osteophytes. It is a type of degenerative osteoarthritis. Similarly, new bone formation can reduce the space in the vertebral foremen that is known as lumbar stenosis and can produce spinal cord compression. And if there is a significant spinal cord compression which we will diagnose with CT scan MRI or lumbar myelogram then we will have to do what is known as a laminatectomy. There are two ways of doing it. We can either cut at the parts interarticularis and thus open the space or we can cut the pedicle. In either situation we open up the space and reduce the compression. So, that is the process for laminatectomy which is done in the case of lumbar spine. This is a picture to show lumbar myelogram and a lumbar stenosis. Thank you very much for watching. If you have any questions or comments please put them in the comment section below. Dr. Sanjay Sanyal signing out.