What makes up lumbar plexus

In the pelvic area, it runs in a groove between the psoas major and iliacus muscles and gives branches to both. It exits the pelvis through the medial aspect of the muscular lacuna. In the thigh, it divides into numerous sensory and muscular branches and the saphenous nerve, its long sensory terminal branch that continues down to the foot. Learning Objectives Describe the lumbar plexus. Key Points The lumbar plexus passes through the psoas major muscle and innervates the skin and muscles of the abdominal wall, thigh, and external genitalia.

The largest nerve that forms part of the lumbar plexus is the femoral nerve, which innervates the anterior thigh muscles and some of the skin distal to the inguinal ligament. The ilioinguinal nerve pierces the lateral abdominal wall and runs medially at the level of the inguinal ligament.

It supplies motor branches to both transversus abdominis and sensory branches to the skin over the pubic symphysis and the lateral aspect of the labia majora or scrotum. The genital branch of the genitofemoral nerve courses differently in females and males.

Key Terms lumbosacral plexus : The anterior divisions of the lumbar nerves, sacral nerves, and coccygeal nerve form this plexus, the first lumbar nerve being frequently joined by a branch from the twelfth thoracic nerve.

Its anatomy is very important for operating on hernia patients. Structure and Distribution The lumbar plexus is a nerve plexus in the lumbar region of the body that forms part of the lumbosacral plexus. Ilioinguinal Nerve This nerve closely follows the iliohypogastric nerve on the quadratus lumborum but then passes below it to run at the level of the iliac crest.

Genitofemoral Nerve Pierces the psoas major anteriorly, below the former two nerves to immediately split into two branches that run downward on the anterior side of the muscle. By Uwe Gile. The sciatic nerve is the largest nerve of the human body and, along with the saphenous nerve , supplies the skin of the lower leg.

After passing through the greater sciatic foramen below the piriformis muscle, it moves along the back of the thigh to the popliteal fossa. Above the popliteal fossa, it usually divides itself into the tibial nerve and the common fibular or peroneal nerve. Even before the division of the sciatic nerve, a fibular part F can be distinguished from a tibial part T.

Each of them makes branches for the following muscles:. After its separation from the sciatic nerve at the popliteal level, the common fibular nerve breaks off into two branches for the sensory innervation of the lateral and posterior lower leg: the lateral sural cutaneous nerve and the communicating branches , which in order to ensure sensory supply of the posterior lower leg, merge with a branch of the tibial nerve to form the sural nerve.

The common fibular nerve moves around the head of a fibula to the anterior side of the lower leg, and, after entering the peroneal fibularis longus muscle, it divides into its terminal branches: the superficial fibular peroneal nerve and the deep fibular peroneal nerve. For motor innervation, see the table below. Image: Deep nerves of the front of the leg. The superficial fibular nerve runs between the two fibular muscles to the dorsum, where it ends in the sensory medial and intermediate cutaneous nerves , which innervate the dorsum and medial border of the foot.

The deep fibular nerve reaches the extensor compartment after breaking through the anterior intermuscular septum of the leg and moves between the tibialis anterior and extensor hallucis longus muscles to the dorsal side of the foot. The sensory terminal branch supplies the skin of the first interdigital space autonomous zone.

The tibial nerve releases a medial sural cutaneous nerve , which merges with the communicating fibular nerves to form the sural nerve that courses alongside the small saphenous vein and moves caudally to the popliteal space between the heads of the gastrocnemius muscle downward in a vertical fashion.

Furthermore, in its course, the tibial nerve lays between the soleus muscle and the lower leg flexors, which it also innervates. Along the medial malleolus , it reaches the plantar aspect of the foot, where it divides into its terminal branches for motor and sensory innervation of the sole: the medial plantar nerve and the lateral plantar nerve.

Image: Diagram of the segmental distribution of the cutaneous nerves of the sole of the foot. Image: Sensory supply to the lower limbs. Our medical articles are the result of the hard work of our editorial board and our professional authors.

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Lecturio is using cookies to improve your user experience. By continuing use of our service you agree upon our Data Privacy Statement. Are you more of a visual learner? Check out our online video lectures and start your anatomy course now for free! Note: In cases of dysfunction of the fibular nerve, a heel strike is no longer possible. Note: In cases of dysfunction of the tibial nerve, standing tiptoe is not possible. Measure content performance. Develop and improve products.

List of Partners vendors. The lumbar plexus is a network of nerves in the lumbar region of your body the abdominal segment of your torso. It's a part of the larger structure called the lumbosacral plexus.

The lumbar plexus is made up of branches of the first four lumbar nerve along with contributions from the subcostal nerve, which is the lowest nerve of the thoracic region the one just above the lumbar area.

The plexus' major function is to supply nerve function to the front part of the thigh. The nerves in your body emerge from the spinal cord and exit to the rest of the body between the vertebrae. The spine is divided up into five sections. The lumbar region of the spine is the third section, with the sacral region below it and the thoracic region above.

Even so, the lumbar region is low in your back, where it naturally curves inward. The sacral and coccygeal regions below it are short, while the thoracic region is the longest.

Once the nerves emerge from the spinal column, they branch out like trees so they can travel to the various muscles, joints, and other tissues they innervate provide nerve function to. All of the spinal nerves are considered mixed, providing both motor function having to do with movement and sensory function having to do with sensation, such as touch and temperature. Shortly after exiting the spine, the nerve splits into three parts. Each part is called a ramus plural is rami. The three rami are:.

You have several nerve plexuses, which are made up of branches of intersecting nerve fibers. The major ones and the areas they serve are:. The lumbar plexus contains the ventral rami front portions of spinal nerves that emerge from between the five lumbar vertebrae L1-L5.

In addition, it's joined by a portion of the lowest thoracic nerve, which emerges from the T12 vertebra just above the lumbar region. This plexus forms alongside the spine and passes through the psoas major muscle, which connects to the lumbar region of the spine and stretches down to the bottom of your pelvis, near where your thigh meets your torso. Small motor branches of the plexus innervate the psoas major, the quadratus lumborum muscle, and the lumbar intertransverse muscle.

Meanwhile, the larger branches continue on, exiting the psoas major muscle through various places. After that, they travel down in front of your hip joint then through and out of the pelvis to reach the front part of the thigh. It gives off branches as it goes. The five main branches of the lumbar plexus are responsible for much of the movement and feeling in your legs.

Most of them have both motor and sensory roles. The first major branch of the lumbar plexus, the iliohypogastric nerve runs to the iliac crest the top and outer edge of your hip bones and across the quadratus lumborum muscle before perforating the transversus abdominis muscle.

There, it divides into its terminal branches. The iliohypogastric nerve provides motor function to the internal oblique and transversus abdominis muscles.

It provides sensory function to a portion of skin in the pubic region. The ilioinguinal nerve has a close relationship with the iliohypogastric. It follows the same course for much of its run and joins the larger iliohypogastric in supplying motor function to the internal oblique and transversus abdominis muscles in the abdominal wall. From there, it travels a separate course and provides sensory function to the skin on the upper-middle thigh, then continues on to the genitalia.

In men, it's responsible for feeling in the skin at the root of the penis and forward part of the scrotum. In women, it innervates the skin over the mons pubis and labia majora.

The genitofemoral nerve divides just outside the psoas major muscle to form a femoral branch and a genital branch. The femoral branch supplies feeling to the skin on the front of the upper thigh. The genital branch is mixed, supplying motor function to the cremaster muscle of the scrotum and inguinal canal.