What Is the Function of the Somatic Nervous System?

The English name of the somatic nervous system is Somatic Nervous System (also known as the animal nervous system). This part of the nerve can be controlled through consciousness . Somatic nerves are distributed on the body surface, bones, joints and skeletal muscles.

The somatic and visceral nervous systems together form the peripheral nervous system of vertebrates.

Chinese name: Somatic nervous system
Foreign name: Somatic Nervous System

Also known as: Animal nervous system
Make up: Vertebrate peripheral nervous system

Overview of the somatic nervous system

Somatic nerves: Somatic nerves distributed to the genitourinary organs include the iliac groin and genital femoral nerves of the lumbar plexus, and the genital nerves of the iliac plexus. They manage skin sensations and striated muscle movements associated with the genitourinary organs.

Somatic nervous system classification

Somatic nervous system groin nerve

The iliac inguinal nerve starts from the lumbar 1 nerve of the lumbar plexus, passes through the posterior wall to the anterior wall of the abdomen, passes through the inguinal canal to the subcutaneous, and manages the skin sensation of the small part of the skin of the medial thigh and the root of the penis and the front of the scrotum (or labia majora).

The iliac inguinal nerve contains the fibers of the 1st lumbar nerve, and the fibers of the 12th thoracic nerve are also added. This nerve runs along the lateral border of the psoas major muscle, along the front of the psoas muscle, behind the kidney, and then through the front of the diaphragm, through the transverse abdominal muscle and the oblique muscle into the inguinal canal. It descends along the lower and outer side of the spermatic cord, passes through the subcutaneous ring of the tube to the superficial fascia, and is distributed on the skin inside the upper thigh. Concurrent branches are distributed in the skin of the root of the penis and the scrotum (women's labia), called the anterior scrotal nerve (women's anterior labial nerve). Its muscular branches are distributed in and control the abdominal wall muscles through which the groin nerve passes.

Somatic nervous system reproductive femoral nerve

The genital femoral nerve starts from the 1st and 2nd lumbar nerves of the lumbar plexus, and passes through the psoas muscle forward to the front of the psoas muscle, and is divided into the femoral and reproductive branches. The thigh branch to the front of the thigh manages a small part of the skin feel. The genital branch enters the spermatic cord of the inguinal canal, runs down the deep side of the cremaster muscle, manages the movement of the cremaster muscle, and ends through the inguinal canal. Together with the iliac inguinal nerve, it manages a small part of the skin of the medial thigh and the root of the penis and the scrotum ( Or the labia majora). Stimulation of the cremaster muscle reflex caused by the upper skin of the medial femoral part, the afferent nerve is the two nerves, the efferent nerve is the genital branch of the reproductive femoral nerve, and the center is at the spinal lumbar 1 and 2 segments.

Somatic nervous system

The pudendal nerve is the main nerve of the perineum and manages skin sensation and striated muscle movement in the perineum. The 2nd to 4th phrenic nerves from the iliac plexus, after synthesizing the pelvic cavity, go around the back of the sciatic spine into the side wall of the sciatic rectal fossa (the sciatic spine is a sign that closes the genital nerve) and is divided into three branches. One is the anal nerve (formerly known as the subrectal nerve), which passes through the adipose tissue of the sciatic rectal fossa around the anal canal, and manages the movement of the external anal sphincter and the feeling of the mucous membrane and perianal skin below the anal canal dentate line. The other two are the perineal nerve and the penile (pedicle) dorsal nerve. They enter the genital canal (Alcock canal) along the side wall of the sciatic rectum with the internal genital arteries, and advance to the urogenital triangle in the canal. The perineal nerve is a mixed nerve that manages the muscles of the urogenital triangle, including the perineal superficial space (or bag) of the cavernous body muscle, the sciatic cavernous muscle, and the deep space (or bag) of the urethral membrane sphincter; The posterior nerve of the scrotum (or labia) is used to manage the skin sensation of the posterior part of the scrotum (or labia majora). In women, it also manages the sensation of the vaginal vestibule and lower vagina. The dorsal nerve of the penis (pedicle) is a sensory nerve that manages the sensation of the skin of the penis and the head (or clitoris) of the penis (pedicle) to the back of the penis (pedicle) to the back of the penis (pedicle).

Because the anterior skin of the scrotum is dominated by the patellofemoral nerve and the reproductive femoral nerve (lumbars 1 and 2), and the posterior is distributed by the pudendal nerves (lumens 2 to 4), the scrotal root is the lumbar 2 nerve distribution area and the sacral 2 nerve distribution area The meeting place is a useful marker for clinical examination of the cutaneous segmental nerve.

Somatic nervous system and somatic nerve related diseases

Inguinal pain syndrome:

1 Overview:

Sacral groin pain syndrome refers to a condition of sacral groin pain caused by injury, stimulation or compression of the nerve and the inferior sacral nerve for various reasons. It is relatively rare in clinical practice.

2. Anatomy and physiology:

The iliac inguinal nerve originates from the L1 spinal nerve, is located below and parallel to the inferior iliac nerve. After this nerve emerges from the outer edge of the psoas major muscle, it crosses the front of the psoas muscle to the medial side of the anterior superior iliac spine, and passes through the transverse abdominal muscles and the oblique muscles. Continue along the spermatic cord (or round ligament) below the external oblique tendon, and finally pass through the external oblique tendon outside the inguinal (shallow) ring and divide the terminal branch to the pubic area, groin and scrotum (Or labia majora) skin. The dermal branches are distributed on the skin of the pubic area, groin, and upper medial thigh, and the anterior branch of the scrotum (or labia majora) to the skin of the front of the scrotum (or upper labia majora). In addition, this nerve still divides a muscle to innervate the lower abdominal wall muscles.

3. Etiology:

This symptom is mostly caused by inguinal hernia repair, appendectomy during intraoperative injury or postoperative scar stimulation of the groin nerve. It can also be caused by the frequent vigorous activities of abdominal muscles (such as athletes) that cause the nerve to pass through the muscular layers of the abdominal wall. Caused by repeated pulling or oppression.

4. Clinical manifestations and diagnosis:

The main symptoms are severe pain in one side of the groin area with paresthesia and allergies in the medial femur and scrotum area. The symptoms worsen when standing, walking or coughing. Patients often take a mild hip flexion and adduction posture, walking slowly in small steps, and there may be obvious tenderness points in the local area.

Pain point lidocaine injection or medial sacral inguinal nerve block of the anterior superior iliac spine is of great significance for clear diagnosis. A diagnosis can be made if the symptoms of pain ease immediately after the injection.

Somatic nervous system function

The sensory nerve fibers of the somatic nervous system can transmit vision, smell, taste, touch and other information collected by the sensory organs of the body to the brain or spinal cord; and the motor nerve fibers are responsible for transmitting the commands issued by the central nervous system To skeletal muscles to produce the desired movement. (Different directions for transmitting nerve impulses are divided into afferent nerves and efferent nerves. Afferent nerves transmit nerve impulses from the periphery to the central nervous system to produce sensations, also known as sensory nerves; and efferent nerves are transmitted from the central nervous system to the surrounding Nerve impulses, which produce movement, are also called motor nerves.)

Somatic nervous system supplement

The nervous system is roughly classified as follows: it is first divided into the central nervous system and the peripheral nervous system. The central nervous system is divided into two parts, the brain and the spinal cord. The peripheral nervous system (PNS) is the nerve that sends out and guides all parts of the human body: the peripheral nerve can be divided into the brain connected to the brain according to the parts connected to the central Nerves and spinal nerves connected to the spinal cord; there are 12 pairs of cerebral nerves and 31 pairs of spinal nerves. It is divided into somatic nervous system and visceral nerve according to different objects. Somatic nerves can be further divided into afferent and efferent nerves; efferent nerves of the visceral nerve can be divided into sympathetic and parasympathetic nerves.