Anatomy: lumbar plexus and its branches

In our body there is nothing superfluous - Mother Nature took good care of this. Although, as noted by some, such an organ as an appendix is not of particular value, and it is possible to live fully without it. But we are not talking about this, but about the important role played by the lumbar plexus, Or plexus lumbalis. Here the accumulation of nerve endings of the pelvic region and lower limbs is concentrated.

The inflammatory processes occurring in this area are accompanied by a neuralgia that covers the lower half of the body. Often with this, there are pains. To clearly understand how the pathological processes occur, you need to know the anatomy of this department well.

Definition

The lumbar plexus is the set of several kinds of nerves. The first three of the spinal nerves take part in its formation. Partially, this can include 12 branches of the thoracic and 4 branches of the spinal cord nerves. Large muscle fibers are the place where the lumbar plexus is located. Anatomy involves finding the nerve branches in front of the transverse processes of the vertebrae of the waist.

These nerve endings are responsible for the innervation of some parts of the muscle fibers, including the skin of the peritoneum. In addition, they are associated with the skin surface of the external genitalia, the medial surface of the shin, the anterior medial side of the thigh. There are several types of nerve endings in this department:

• Ilio-hypogastric;
• Ilio-inguinal;
• Femoral-genital;
• lateral;
• Blocking;
• femoral.

Let's take a closer look at what they are and where they lie. Conditionally, all nerves can be divided into two triplets.

The first three nerves

The ilio-hypogastric nerves of the lumbar plexus are formed from the anterior 12 thoracic and 1 lumbar branches of the nerve endings. From them they pass through the large lumbar muscle and then come into contact with the front surface of the square muscle of the waist, being thus near the kidney. Further, the nerve passes from the top down, keeping its direction from the front. On the way to the iliac crest, it perforates the transverse abdominal muscle and then lies between it and the internal oblique muscle fibers of the abdomen. The further way lies already between both oblique muscles.

In the deep inguinal ring, the iliac-hypogastric nerve also permeates the internal oblique muscle and the broad tendon plate of the external oblique muscle. After this, it branches into the dermal processes of the abdominal wall above the pubic articulation. Its function includes the innervation of the majority of abdominal muscles. Also, the nerves pass through the skin in the region of the thigh, buttocks, anterior abdominal wall above the pubis.

Another branch, which originates from the anterior nerve root, but is located just below the previous one, is called the ilio-inguinal nerve, which also enters the lumbar plexus. Its anatomy is different for men and women. In the strong sex, the nerve passes through the inguinal canal and splits into small cutaneous branches on both surfaces of the thigh near the scrotal nerve cells. The latter are responsible for the innervation of the skin of the genital organ and partially the scrotum. In women, these same endings connect the central nervous system with the skin on the pubic and large labia.

The femoral-genital pervades the large lumbar muscle and even divides into two branches - the genital and femoral. The genital, otherwise known as the seminal nerve, is directed downward, and, like the seminal cord, passes through the inguinal canal. In the male body, it is associated with the muscle that is responsible for raising the testicle, the skin of the scrotum, as well as the fleshy membrane and the surface of the skin of the upper median region of the thigh. The female lumbar plexus is arranged differently - the nerve forms a pair with a round ligament of the uterus of the inguinal canal and then goes to the skin of the large labia.

The second femoral branch from this general end points downwards and runs laterally from the external iliac artery directly under the inguinal ligament. Below her nerve is divided into branches of the skin surface of the thigh.

The second three nerves

Below all three listed nerves are three larger branches. These are the lateral, femoral and inhibitory nerve endings. The first of the list is located on the side of the inguinal ligament. It can be on the surface or inside the sartorius muscle, being under the connective tissue membrane. The nerve is responsible for the sensitivity of the lateral surfaces of the buttocks just below the large trochanter of the hip bone and closer to the lateral surface of the thigh.

Continuing to disassemble, exactly how the lumbar plexus is formed, it is necessary to pass to the obturator nerve. It goes down along the large lumbar muscle, more precisely, along its edge and falls into the region of the small pelvis. Joining the circulatory system, he, along with the vessels, goes to the thigh area along the occlusion channel, located between the leading muscles. The nerve is associated with a group of adductor muscles, knee and hip joints. Also, the nerve innervates the surface of the middle part of the femur closer to the knee.

Of the entire lumbar plexus, the femoral branch is the largest. It originates at the border of the fifth vertebra of the waist in the region of the same muscle fibers. Exiting the lateral edge of the muscle, the nerve runs lower between the two other muscle groups: the lumbar and iliac, walking under the latter's membrane.

Going under the inguinal ligament, the nerves of the lumbar plexus are divided into numerous branches that are associated with the skin and muscles of the anterior part of the thigh, knee and hip joints.

Part of the whole

Nerve endings of the waist are part of a common system called the "lumbosacral plexus". The branches of the lumbar, sacral and coccygeal divisions, intertwined with each other, form two main plexuses: lumbar and sacral. With the first term everything is now clear, you can move on to another definition.

In the formation of the sacral plexus (plexus sacralis) takes part of the anterior branch that comes from the fourth and fifth lumbar, as well as from the first to the third sacral branches of the spinal nerve endings. The lumbar plexus itself is located in the small pelvis directly on the connective tissue membrane of the pear-shaped muscle. It is represented in the form of a thick plate of triangular shape, the apex of which is facing the sub-cervical slit.

The base of the triangle is near the pelvic holes. In this case, some of the plexus is located in front of the sacrum, and the other - in front of the pear-shaped muscle. On all sides it is surrounded by a loose connective tissue. As in the lumbar region, there is also a set of nerve endings, which can be either short or long.

Short nerves of the sacral department

Short branches represent the following nerves:

• Gluteal (upper and lower);
• sexual;
• Internal locking;
• Pear-shaped;
• The nerve of the square muscle of the thigh.

Gluteal nerves of the lumbosacral plexus are divided into upper and lower. The first pair with the gluteal artery emerges from the pelvic cavity through the supragene-like opening. The nerve is associated with the small and medium gluteal muscles, as well as fibers connected to the wide fascia of the thigh. The lower nerve, together with the artery, leaves the pelvic area through the sub-necklet and joins with the gluteus majorus. But in addition to it, it is associated with the capsule of the hip joint.

Through the same podrushevidnogo aperture the cavity of the small pelvis leaves the genital nerve, from the rear side passes around the ischium and goes straight to the ischium-rectum fossa. Here it is divided into lower rectal and perineal branches. And the first are associated with the external sphincter of the anus and the skin of the anal region. The latter are responsible for the innervation of muscles and skin of the perineum and scrotum of the male body. A little differently arranged female lumbosacral plexus. Anatomy is distinguished by the fact that the crotch branch is connected with the large labia.

The long nerves of the sacral department

Long branches are represented by:

• The posterior cutaneous nerve;
• Sciatic nerve.

The posterior cutaneous nerve end leaves the small pelvis along the sub-necked opening, descending not far from the sciatic nerve. The posterior femoral cutaneous nerve near the lower edge of the gluteus maximus is divided into the lower gluteal and perineal nerve branches. The lower branch innervates the skin of the lower surface of the buttocks.

The posterior cutaneous femoral branch extends along the groove between the semitendinous and biceps femoris muscles. Its branches penetrate the wide fascia of the thigh and are divided into smaller ones from the inner surface of the thigh, reaching the popliteal fossa.

The sciatic nerve ending, entering the sacral and lumbar plexus, is the largest branch in the human body and deserves special attention. Through a podrug-like opening, the nerve leaves the pelvis along with other nerves (lower gluteal, genital, posterior cutaneous femoral) and the sciatic artery, going down. Approximately on one line with a diamond-shaped depression that is behind the knee joint, it divides into two branches: tibial and common peroneal.

Tibial branch

It is vertically directed downwards towards the soleus muscle of the shin canal. Throughout its entire length this nerve is divided into numerous branches. Some of them approach the triceps muscles of the lower leg, others are directed to the long flexing muscle fibers of the fingers and the big toe. There are also those that are connected to the plantar and popliteal muscle.

The most sensitive endings, included in the sacral and lumbar plexus, are connected with the capsule of the knee joint, the interosseous membrane of the shin, the ankle joint, the bones of the shin. The largest sensitive branch of the tibial branch is the medullary cutaneous nerve. It departs from this branch and goes under the dermal surface and is intertwined with the dermal cavity nerves, which, in turn, comes from the common peroneal nerve.

The result of the fusion of these two endings is the formation of the gastrocnemius nerve. It first runs sideways from the ankle and then goes along the lateral edge of the foot. At this point it is already called the lateral dermal nerve, responsible for the innervation of the skin in these areas.

Common fibular branch

It passes slightly away from the cervix of the fibula in the place where the popliteal fossa is located. Continuing to consider the lumbar plexus and its branches, it is worth noting that in this place the latter are divided into two main branches:

• Superficial;
• Deep.

The superficial nerve is directed downwards. His duties include the innervation of a short and long fibular muscle. Leaving this channel, the nerve goes to the rear side of the foot, where it divides into medial and intermediate dorsal skin endings.

The medial nerve provides sensitivity to the skin of the back of the foot near its lateral edge, as well as the back of the skin 2 and 3 fingers. For the innervation of the back of the skin surface 3, 4 and 5 fingers corresponds to the intermediate cutaneous nerve end.

The deep nerve enters the opening of the anterior intermuscular septum of the lower leg and, accompanied by the same-named artery, rushes downward. At the shin level, the nerve is divided into several ends that connect the anterior tibial muscle and the long muscle of all toes. Approximately on the border of the first intercellular gap, this nerve has two rear branches, innervating the skin surface of the first and second fingers.

Pathological situations

One of the most common ailments is the defeat of the lumbosacral plexus, which is associated with a pinch or pinching of the sciatic nerve. In this case, the largest nerve is squeezed, which causes strong pain in the leg. Almost always, pathology occurs only on one side and rarely when it proceeds in a two-sided form. The male half of humanity, which is connected with hard physical work, is in a zone of high risk.

In medicine, this disease is referred to as sciatica, in the course of diagnosis it can be classified as sciatic neuralgia or lumbosacral radiculitis. This name comes from the Greek word "ishia", which in translation means "seat". The sciatic nerve in Latin is called so - nervus ishiadicus.

Symptomatics

The main symptom that indicates the defeat of the lumbar plexus are strong pain sensations of the buttocks and legs, which can occur in different manifestations. Often the pain is so strong that a person loses consciousness. In other cases, the pain may be burning, cutting or stitching. There are also possible such symptoms:

• In a standing position it is impossible to rely on a sore leg, and lying down you have to look for a comfortable position.
• The pain comes mostly at night, especially after working in cold weather.
• In a number of cases, the pathology first appears on the back of the thigh, and then reaches the shin and foot.
• If you stay in one position for a long time (to lie, sit), the pain intensifies, which also manifests itself with prolonged walking.
• Sneezing, coughing, laughing also provoke the onset of pain.
• After taking appropriate medications or after stihaniya attacks, residual pain sensations pass to the lower back.

Often pinching of the spine of the lumbosacral plexus does not go in vain and can lead to disruption of the gait and cause sweating of the feet. You can also feel a tingling or burning of the lower leg and foot. Often, because of the disease, the leg in the knee is almost impossible to bend. The same can be said about the toes and feet, which can not be turned.

Diagnostics

Define the defeat of the sciatic nerve will help an obvious clinical picture, which describes the patient at the doctor's reception. Any specialist will notice a change in the nature of tendon reflexes and sensitivity on the side to which the patient complains. Sometimes a primary examination does not allow you to make an accurate diagnosis of the ailment that has arisen. In this case, it is necessary to conduct additional studies, among which we can distinguish:

• X-ray;
• Computed tomography;
• MRI;
• Ultrasound;
• Radioisotope scanning of the spine.

Thanks to computed tomography, which is a more accurate radiographic method, even minor changes in the spine can be detected.

But in some cases, when this test is contraindicated, the doctor appoints MRI of the lumbosacral plexus.

Treatment

To get rid of the pathology resort to one of two methods of treatment - conservative or operative. But they always begin with the first method, which includes a complex of various activities. In acute sciatica, a bed rest on a rigid mattress with minimal motor activity and a diet is recommended. You need to eat warm, not spicy, not smoked and not fried, mostly liquid food (meat vegetable soups and milk porridge).

Medicamental treatment involves taking medications prescribed by your doctor. As soon as the pain begins to recede, therapeutic gymnastics is shown. All exercises are selected depending on the nature of the disease.