There is nothing superfluous in our body - mother nature took good care of it. Although, as some note, such an organ as the appendix is not of particular value, and it is quite possible to live fully without it. But this is not about that, but about the important role played by the lumbar plexus, or plexus lumbalis. The cluster of nerve endings of the pelvic region and lower extremities is concentrated here.
Inflammatory processes occurring in this area are accompanied by neuralgia, which covers the lower half of the body. Often this causes pain. To clearly understand how pathological processes occur, you need to know the anatomy of this department well.
Definition
The lumbar plexus is a collection of several types of nerves. The first three spinal nerves take part in its formation. Partially, the 12th branch of the thoracic and the 4th branch of the spinal nerve endings can also be included here. 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 vertebraelower back.
These nerve endings are responsible for the innervation of certain parts of the muscle fibers, including the skin of the peritoneum. In addition, they are associated with the skin surface of the external genital organs, the medial surface of the lower leg, and the anteromedial side of the thigh. In total, several types of nerve endings can be distinguished in this department:
- ilio-hypogastric;
- ilioinguinal;
- femoral-genital;
- lateral;
- obturator;
- femoral.
Let's take a closer look at what they are and where they lie. Conventionally, all nerves can be divided into two triplets.
The first trio of nerves
The iliac-hypogastric nerves of the lumbar plexus are formed from the anterior 12th thoracic and 1st lumbar branches of the nerve endings. From them they pass through the psoas major muscle and then come into contact with the anterior surface of the square muscle of the lower back, thus being near the kidney. Further, the nerve passes from top to bottom, keeping its direction from back to front. On the way to the iliac crest, it penetrates the transverse abdominal muscle and then lies between it and the internal oblique muscle fibers of the abdomen. The further path lies already between both oblique muscles.
In the deep inguinal ring, the iliohypogastric nerve also pierces the internal oblique muscle and the broad tendon plate of the external oblique muscle. After that, it branches into skin processes of the abdominal wall above the pubic symphysis. Its function includes the innervation of most of the abdominal muscles. Also nervespass through the skin in the thigh, buttocks, anterior abdominal wall above the pubis.
Another branch that originates from the anterior nerve root, but is located just below the previous one, is called the ilioinguinal nerve, also included in the lumbar plexus. Its anatomy is different for men and women. In the stronger sex, the nerve passes through the inguinal canal and breaks up into small skin branches on both surfaces of the thigh near the scrotal nerve cells. The latter are responsible for the innervation of the skin of the penis and partly of the scrotum. In women, these same endings connect the central nervous system with the skin on the pubis and labia majora.
The femoro-genital permeates the psoas major muscle and even splits into two branches - the genital and femoral. The genital, otherwise called the spermatic nerve, is directed downward and, like the spermatic 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 with the fleshy membrane and skin surface of the superomedial thigh. The female lumbar nerve plexus is arranged differently - the nerve pairs with the round ligament of the uterus of the inguinal canal and then goes to the skin of the labia majora.
The second femoral branch from this common ending is directed downward and runs to the side of the external iliac artery directly under the inguinal ligament. Below, her nerve divides into branches of the skin surface of the thigh.
The second trinity of nerves
Below all three listed nervesthere are three larger branches. These are the lateral, femoral and obturator 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 tailor muscle, being under the connective tissue sheath. The nerve is responsible for the sensation of the lateral surfaces of the buttocks just beyond the greater trochanter of the thigh bone and closer to the lateral surface of the thigh.
Continuing to analyze how exactly the lumbar plexus is formed, it is worth moving on to the obturator nerve. It goes down along the large lumbar muscle, more precisely, along its edge and enters the pelvic area. Joining the circulatory system, together with the vessels, it enters the thigh area through the obturator canal, located between the adductor muscles. The nerve is associated with a group of adductor muscles, knee and hip joints. The nerve also innervates the surface of the middle part of the thigh closer to the knee.
Of the entire lumbar plexus, the femoral branch is the largest. It originates on the border of the fifth vertebra of the lower back in the region of the muscle fibers of the same name. Coming out from the lateral edge of the muscle, the nerve goes below between two other muscle groups: lumbar and iliac, going under the shell of the latter.
Going under the inguinal ligaments, the nerves of the lumbar plexus divide into numerous branches that are connected to the skin and muscles of the front of the thigh, knee and hip joints.
Part of the whole
The nerve endings of the lower back are part of a general system called "lumbar-sacral nerve plexus". The branches of the lumbar, sacral and coccygeal regions, intertwining with each other, form two main plexuses: lumbar and sacral. Now everything is clear with the first term, you can move on to another definition.
In the formation of the sacral plexus (plexus sacralis), part of the anterior branch takes part, which 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 piriformis muscle. It is presented in the form of a thick triangular plate, the apex of which is turned towards the subpiriform gap.
The base of the triangle is near the pelvic openings. In this case, some part of the plexus is located in front of the sacrum, and the other - in front of the piriformis muscle. On all sides it is surrounded by loose connective tissue. As in the lumbar region, there is also a set of nerve endings here, which can be either short or long.
Short sacral nerves
Short branches represent the following nerves:
- gluteal (upper and lower);
- sexual;
- internal obturator;
- pear-shaped;
- quadraus femoris nerve.
The gluteal nerves of the lumbosacral plexus are divided into upper and lower. The first, together with the gluteal artery, exits the pelvic cavity through the suprapiriform opening. The nerve is associated with the gluteus minimus and medius, as well as fibersconnected to the broad fascia of the thigh. The lower nerve, together with the artery, leaves the pelvic region through the subpiriform opening and connects with the gluteus maximus muscle. But besides it, it is connected with the capsule of the hip joint.
Through the same subpiriform opening, the pelvic cavity leaves the pudendal nerve, from the back bypasses the ischium and goes straight to the ischiorectal fossa. Here it divides into lower rectal and perineal branches. Moreover, the former are associated with the external sphincter of the anus and the skin of the anal region. The latter are responsible for the innervation of the muscles and skin of the perineum and scrotum of the male body. The female lumbosacral plexus is arranged a little differently. The anatomy is different in that the perineal branch is connected to the labia majora.
Long nerves of the sacrum
Long branches are represented by:
- posterior cutaneous nerve;
- sciatic nerve.
The posterior cutaneous nerve ending leaves the pelvis through the subpiriform foramen, descending close to the sciatic nerve. The posterior femoral cutaneous nerve near the lower edge of the gluteus maximus divides into inferior gluteal and perineal nerve branches. In this case, the lower branch innervates the skin of the lower surface of the buttocks.
The posterior cutaneous femoral branch runs along the groove between the semitendinosus and biceps femoris muscles. Its branches penetrate the wide fascia of the thigh and are divided into smaller ones from the inside.surface of the thigh, reaching the popliteal fossa.
The sciatic nerve ending, which enters the sacral and lumbar plexus, is the largest branch in the human body and deserves special attention. Through the subpiriform opening, the nerve leaves the pelvis along with other nerves (lower gluteal, genital, posterior cutaneous femoral) and the sciatic artery, heading down. Approximately in line with the diamond-shaped depression behind the knee joint, it divides into two branches: the tibial and the common peroneal.
Tibial branch
It is directed vertically downwards towards the soleus muscle of the ankle-popliteal canal. Throughout its length, this nerve is divided into numerous branches. Some of them go to the triceps muscle of the lower leg, others go to the long flexor muscle fibers of the fingers and big toe. There are those that are connected to the plantar and popliteal muscles.
The most sensitive endings, included in the sacral and lumbar plexus, connect with the capsule of the knee joint, the interosseous membrane of the leg, the ankle joint, and the bones of the leg. The largest sensory branch of the tibial branch is the medial cutaneous caviar nerve. It departs from this branch and goes under the skin surface and intertwines with the cutaneous caviar nerve, which, in turn, comes from the common peroneal nerve.
The result of the fusion of these two endings is the formation of the sural nerve. He firstruns along the side of the ankle and then goes along the lateral edge of the foot. In this place, it is already called the lateral dorsal cutaneous nerve, which is responsible for the innervation of the skin in these areas.
Common fibular branch
It runs slightly away from the neck of the fibula where the popliteal fossa is located. Continuing to consider the lumbar plexus and its branches, it is worth noting that at this point the latter are divided into two main branches:
- superficial;
- deep.
Superficial nerve pointing down. His duties include the innervation of the short and long peroneal muscles. Leaving this channel, the nerve goes to the back of the foot, where it divides into medial and intermediate dorsal skin endings.
The medial nerve supplies sensitivity to the skin of the back of the foot near its lateral edge, as well as the back of the skin of the 2nd and 3rd fingers. The intermediate cutaneous nerve ending is responsible for the innervation of the back of the skin surface of fingers 3, 4 and 5.
The deep nerve enters the opening of the anterior intermuscular septum of the leg and, accompanied by the artery of the same name, rushes down. At the level of the lower leg, the nerve divides into several endings that connect the anterior tibial muscle and the long muscle of all toes. Approximately at the border of the first intermetatarsal space, this nerve has two dorsal branches that innervate the skin surface of the 1st and 2nd fingers.
Pathological situations
One of the most common ailments is the defeat of the lumbarsacral plexus, which is associated with pinching or pinching of the sciatic nerve. In this case, the largest nerve is compressed, which causes severe pain in the leg. Almost always, pathology occurs only on one side and rarely occurs in a bilateral form. The male half of humanity, which, on duty, is associated with hard physical work, is at increased risk.
In medicine, this disease is referred to as sciatica, during the diagnosis it can be classified as sciatic neuralgia or sciatica. This name comes from the Greek word "ishia", which means "seat" in translation. The sciatic nerve in Latin is called like this - nervus ishiadicus.
Symptomatics
The main symptom that indicates damage to the lumbar plexus is severe pain in the buttocks and legs, which can occur in different manifestations. Often, the pain is so severe that the person loses consciousness. In other cases, the pain may be burning, cutting or stabbing. The following symptoms are also possible:
- In a standing position, it is impossible to lean on a sore leg, and lying down you have to look for a comfortable position.
- Pain comes mostly at night, especially after working in cold weather.
- In some cases, the pathology first appears on the back of the thigh, and then reaches the lower leg and foot.
- If you stay in one position for a long time (lie down, sit), the pain intensifies, which also manifests itself andwhen walking for a long time.
- Sneezing, coughing, laughing also provoke pain.
- After taking the appropriate drugs or after the attacks subside, residual pain passes to the lower back.
Often, pinching of the lumbosacral plexus root is not in vain and can lead to impaired gait and cause sweating of the feet. You can also feel a tingling or burning sensation in the lower leg and foot. Often, due to the disease, the leg at the knee is almost impossible to bend. The same can be said for toes and a foot that cannot be rotated.
Diagnosis
To determine the lesion of the sciatic nerve will help a clear clinical picture, which is described by the patient at the doctor's appointment. Any specialist will notice a change in the nature of the tendon reflexes and sensitivity on the side that the patient complains about. Sometimes the initial examination does not allow to make an accurate diagnosis of the disease that has arisen. In this case, it is necessary to conduct additional research, among which are:
- x-ray;
- computed tomography;
- MRI;
- ultrasound;
- radioisotope scan of the spine.
Thanks to computed tomography, which is a more accurate X-ray method, even minor changes in the spine can be detected.
But in some cases, when this study is contraindicated, the doctor prescribes an MRI of the lumbosacral plexus.
Treatment
Forgetting rid of pathology resort to one of two methods of treatment - conservative or surgical. But they always start with the first technique, which includes a complex of various activities. In acute sciatica, bed rest on a hard mattress with minimal physical activity and a diet are recommended. You need to eat warm, not spicy, not smoked or fried, mostly liquid food (meat vegetable soups and milk porridge).
Drug treatment involves taking medications prescribed by the attending physician. As soon as the pain begins to recede, therapeutic exercises are indicated. All exercises are selected depending on the nature of the disease.
