![]() Intertransversarii muscle (mediales lumborum and laterales lumborum) - This muscle is specifically found from L1-L5.Multifidus muscle - This is a long muscle that traverses the length of the back and functions in stabilizing and rotating the lumbar spine.Spinalis muscle - This is a long muscle that is part of the erector spinae bundle of muscles and tendons, which helps the spine with movement and also helps in maintaining posture and staying erect when standing.The longissmus muscle can extend the spine upon bilateral contraction, and unilateral contraction can bend the spine laterally to the same side. Longissimus muscle - This is a long muscle with a lumbar vertebral origin at the transverse processes and spinous processes.Muscles affecting lumbar vertebrae function Specific lumbar vertebraeĬauda equina in a cadaver: This nerve bundle contains spinal nerves L2-L5, S1-S5 and Co. The transverse processes are positioned in front of the articular processes instead of behind them as in the thoracic vertebrae, and are homologous with the ribs. In L1-元, the transverse processes arise from the junctions of the pedicles and laminae, but in L4-L5, they arise from the pedicles and posterior portions of the vertebral bodies since they are set farther forward. These processes are horizontal in L1-元, and incline a little upward in L4-L5. Transverse processes are long and slender, with changing morphology from L1 to L5. This anatomical conformation allows for resistance against the twisting of the lower spine. The superior processes are concave and face medially (like when the palms of the hands are facing each other when about to clap), whereas the inferior processes are convex and face lateralward towards the superior processes of the next vertebra. The superior and inferior articular processes are well-defined, and project upward and downward from the junctions of pedicles and laminae, respectively. The vertebral foramen is triangular-shaped within the arch, and larger in size than in the thoracic vertebrae, but smaller than in the cervical vertebrae. ![]() Laminae connect the spinous process to the pedicles. The upper lumbar laminae regions are taller instead of wider, whereas the lower lumbar laminae regions are wider instead of tall. The laminae are strong, broad, and short in morphology, and form the posterior portion of the vertebral arch. Want to learn more about the vertebral column? Our spine quizzes and labeled diagrams are the best way to learn and consolidate knowledge at the same time. The angle in the axial plane also increases from 10 to 20 degrees from L1 to L5. The pedicles also change in morphology from L1 to L5, increasing in width from 9 mm up to 18 mm at L5. As a result, the inferior vertebral notches have considerable depth. The pedicles are very strong and are directed backwards from the upper part of the vertebral body. The vertebral arch consists of a pair of pedicles and a pair of laminae, which encircles the vertebral foramen that ultimately supports 7 processes. Lumbar vertebrae from the human cadaver: Notice how lumbar vertebrae have massive bodies to bear the body weight.Įach lumbar vertebra has a vertebral body and a vertebral arch.
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