L3 — third lumbar vertebra (Vertebra lumbalis tertia)

Layer: Bones

Educational content only — not medical advice.

Anatomy

L3, the third of five massive lumbar vertebrae carrying the trunk's weight: a broad kidney-shaped body, a hatchet-shaped horizontal spinous process and slender transverse processes. Its sagittally oriented facet joints lock rotation in favour of low-back stability.

Clinical notes

Lumbar disc herniation at L3 may compress the L4 root, producing anterior-thigh and groin pain (femoral distribution) rather than the below-knee sciatica of the lower levels.

Related structures

Educational references

FAQ

What is the role of the L3 — third lumbar vertebra?

L3, the third of five massive lumbar vertebrae carrying the trunk's weight: a broad kidney-shaped body, a hatchet-shaped horizontal spinous process and slender transverse processes. Its sagittally oriented facet joints lock rotation in favour of low-back stability.

Why is the L3 — third lumbar vertebra clinically important?

Lumbar disc herniation at L3 may compress the L4 root, producing anterior-thigh and groin pain (femoral distribution) rather than the below-knee sciatica of the lower levels.

Source & license

Derived from Z-Anatomy (Gauthier Kervyn et al.), CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0/); upstream geometry from BodyParts3D, © The Database Center for Life Science. license details