Where is the first lumbar vertebra?

The human body is very complex, and the bones are also distributed in a relatively regular pattern. People have skulls, shoulder bones, cervical spine, ischium, limbs, etc. The functions and roles of each bone are different, and they do their own things. As ordinary people have not been exposed to anatomy, they know very little about the specific distribution of human bones. So today I will give you some knowledge in this area. Next, I will tell you where the first lumbar vertebra of the human body is and how to find it?

1. Definition of Lumbar Spine:

Lumbar vertebrae: The vertebral body is relatively large; the spinous processes extend horizontally and plate-like to the back, and the gaps between adjacent spinous processes are wide, which can be used for lumbar puncture; the articular process articular surfaces are in the sagittal position. The human body has five lumbar vertebrae, each of which consists of a vertebral body in the front and an attachment in the back. The inner edge of the vertebral lamina is arch-shaped, and the vertebral arch and the posterior edge of the vertebral body form a vertebral foramen. The upper and lower vertebral foramina are connected to form the vertebral canal, through which the spinal cord and nerves pass. The joint between the two vertebral bodies is the intervertebral disc. It consists of two parts: the annulus fibrosus and the nucleus pulposus. The nucleus pulposus is located in the center of the intervertebral disc. It is a water-rich, jelly-like elastic protein. Surrounding the nucleus pulposus is the annulus fibrosus, which connects the two vertebrae together and firmly fixes the nucleus pulposus in the center.

2. Structure

The intervertebral disc usually consists of three parts: ① cartilage plate; ② annulus fibrosus; ③ nucleus pulposus. The intervertebral disc is actually a sealed container with cartilage plates on the top and bottom. It is a transparent cartilage covering the vertebral body on the top and the bone surface in the middle of the ring on the bottom. The upper and lower cartilage plates together with the annulus fibrosus seal the nucleus pulposus. The annulus fibrosus is composed of fibrocartilage with collagen fiber bundles and is located around the nucleus pulposus. The fiber bundles of the fiber ring cross and overlap obliquely, making the annulus fibrosus a solid tissue that can withstand large bending and torsional loads. The front and sides of the annulus fibrosus are thicker, while the back side is thinner. The anterior part of the annulus fibrosus has a strong anterior longitudinal ligament, and the posterior longitudinal ligament on the posterior side is narrower and thinner. Therefore, the nucleus pulposus is prone to protrude posteriorly and compress the nerve roots or spinal cord. When the vertebral body is subjected to longitudinal load, the nucleus pulposus uses the annulus fibrosus to expand outward with its good elasticity to buffer the pressure and have a shock-absorbing effect, thus preventing concussion of the brain when walking, jumping, or running. It can also maximize the mobility of the spine, allowing people to move the waist in all directions. This structure of the intervertebral disc allows the vertebrae to move with the help of the elasticity and movement of the nucleus pulposus and the tension of the annulus fibrosus. However, once the annulus fibrosus is damaged, the nucleus pulposus wrapped therein will protrude outward through the damaged annulus fibrosus, which is called intervertebral disc herniation (extrusion), compressing the spinal cord or nerve roots and causing corresponding symptoms and signs.

3. Structure of the lumbar spine

The body is stout, kidney-shaped in cross section, and the vertebral foramen is triangular. The upper and lower articular processes are thick and the articular surface is sagittal. There is an oval protrusion on the posterior edge of the superior articular process, called the mastoid process. The spinous process is broad, short, plate-like, and extends horizontally toward the back. The spaces between the spinous processes are relatively wide, and lumbar puncture can be performed here clinically.

4.How to find the location of the first lumbar vertebra?

The area where the ribs are not connected is the lumbar vertebrae. Normally, there are five lumbar vertebrae in total. From top to bottom, there is the first lumbar vertebra, followed by the 2nd, 3rd, 4th, 5th, and fifth lumbar vertebrae and the sacrum. There is an intervertebral disc between two adjacent lumbar vertebrae.