Anatomy of the perineum includes a part of the body, which is bounded on different sides by the pubis, the coccygeal apex and tubercles of the ischium with the hump-sacral ligaments. If the legs are abducted or bent, it has a rhombic shape, which is formed by the bone apparatus of the pubis and ischium, as well as the spinous-sacral ligaments, covered by the large ischial muscles.
Differences in the anatomy of the perineum of men and women
In the middle of the perineum in the anteroposterior side is a tendon suture. In men, it goes into the scrotal suture. The perineum is the lower wall of the body. Thus, it covers the pelvis from below. Through it go the urination canal, vagina and rectum in women.
Perineum function
The perineum helps hold the pelvic organs in place. Prevents uncontrolled excretion of human waste, regulates the excretion of urine and feces.
It is important to know the topographic anatomy of the pelvis and perineum. This needspay special attention when it comes to a female patient. Structural features are always taken into account by surgeons during intervention in the elimination of perineal tears of the 1st degree during childbirth.
Building
The obstetric perineum is a muscular segment between the labia majora and the otkhodnikov hole. The term is used exclusively in the narrow sense of the word.
In a broad sense, anatomy defines the perineum as the junction of the anterior and posterior triangle.
The anterior triangle is the area related to the genitourinary system. Filled with frontal muscular-fascial plate. She is the urogenital diaphragm. Contains passing deeply transverse fibers and two sheets of fascia. The latter close the muscle fibers up and down. In front of the urethra, the muscular-fascial plate does not reach the junction of the pubis and forms a perineal ligament that runs transversely. The area between the transverse and annular ligaments of the pubic fusion enters the arterial structures of either the penis or the clitoral region.
The posterior triangle is the region of the rectum that passes into the anus. Fills the bottom of the pelvis horizontally with the diaphragm. It is formed by the plexus of both muscles that lift the anus, as well as both fibrous structures of the coccyx with fascia. Through the diaphragm of the pelvis, the intestine ends with the anus. Through the diaphragm of the genitourinary structure in men, the urination canal, the scrotal sac and the root of the penis go, in women - parts of the external reproductive system.
Anatomy of the muscles of the perineum
Muscle fibers form deep and superficial layers.
Layers of the diaphragm next to the genitourinary system:
1. Superficial: spongy bulbous, cavernous ischial, transverse superficial.
2. Deep: transverse-deep, urinary tract closure.
Spongy-bulbous layers have a paired structure, close the lower lateral part and the spongy area. Spliced with the same layers on the reverse side. Together they form a longitudinal seam. Main function: compression of the urethral canal to remove urine or seminal fluid. In women, they are divided into two parts, which narrow the vagina.
Cavernous-sciatic fibers come from both tubercles of the ischium. Attached to the cavernous body. Main function: compression of the venous passages of the clitoris or penis; thickening of the penis and its elevation during the filling of the corpus cavernosum with blood.
Cross-surface layers are paired structures that lie between two diaphragms. They start from the tubercles of the buttocks on both sides. Aimed towards the center of the tendons in order to strengthen.
The transverse deep muscle is a flat fibrous structure that envelops the membranes of the urination canal. It goes from the tubercles of the ischium and the bottom of the bone apparatus of the ischium to the middle to form the tendon suture. Strengthens the diaphragm of the genitourinary system. Contains a channel for the emission of urine, as well as the vagina. In the place of passage of the urination canal, muscle fibers ring it, forming a kind of contactor. It serves as a valveurethra.
Muscles descending to the perineum
The tissues responsible for the elevation of the anus, as well as the coccygeal muscles, form a deep layer.
The levator ani muscle looks like a flat triangle that goes to the descending part of the pubic bones, the licoral bundles inside the closing muscle, and the floor of the pelvis at the spine of the ischium. Part of the muscles goes in the opposite direction to limit the mobility of the straight section of the intestine. Spliced with bundles on the reverse side. The other half of the muscles runs along the sides of the prostate and bladder (in the female, the vagina). Here they fuse with the fibers surrounding the bladder and vagina, then reverse where they attach to the lower thirds of the spine and the coccygeal-anal ligaments.
The coccyx muscle lies behind the pelvic diaphragm. It starts from the bone apparatus of the ischium and spinous-sacral ligaments. Attaches to the sides of the lower spine.
The pelvic diaphragm muscle forms a layer on the surface.
This includes an anal closure fiber. According to the anatomy of the perineum, it is located in the anal circle above the main muscle responsible for raising the anus. Works as an external arbitrary closure of the rectum exit. Together with muscle bundles, it forms a semicircle. The bundles lying on the surface go into the subcutaneous tissue, the bundles of which, in turn, start from the lower third of the spinal column and end in the center of the tendons. The deepest sections coverthe anus, as well as the muscle responsible for lifting it.
Pelvic and perineal lictor bundles
The walls of the pelvic space, as well as the organs of the small pelvis, are framed by lictor bundles.
In the crotch of women and men, the following lictor bundles are distinguished:
- proper pelvic;
- parietal pelvic bundles;
- visceral;
- beams of the peritoneal and perineal regions;
- upper bundles of the pelvic diaphragm;
- lower bundles of the pelvic diaphragm;
- upper bundles of the diaphragm of the genitourinary system;
- lower bundles of the diaphragm of the genitourinary system;
- bundles lying on the surface of the perineum.
According to the anatomy of the perineum, the lictor bundles have a restrictive and strengthening function.
