Muscles of the perineum. Pelvic diaphragm

Muscles of the perineum. Diaphragm of the pelvis.Anatomy, function, blood supply and innervation of muscles of muscles of the pelvic diaphragm
~ 2 min

The perineum (perineum) is a structure that covers the exit from the pelvic cavity. It has a rhomboid shape and has the following borders: the pubic symphysis anteriorly, the apex of the coccyx inferiorly, the lower branches of the pubis and ischium bones, as well as ischial tuberosities bilaterally.

Perineum (perineum)
Perineum (perineum)

In the center of the perineum, the so-called central tendon of the perineum (centrum tendineum) is located. The median perineal raphe (raphe perinei) runs along the perineum in the anteroposterior direction.

Central tendon of the perineum (centrum tendineum)
Central tendon of the perineum (centrum tendineum)
Central tendon of the perineum (centrum tendineum)
Central tendon of the perineum (centrum tendineum)
Perineal raphe (raphe perinei)
Perineal raphe (raphe perinei)
Perineal raphe (raphe perinei)
Perineal raphe (raphe perinei)

The structure of the perineum includes a fairly large number of muscles. The line that connects the ischial tuberosities divides the perineum into two important zones:

The urogenital diaphragm (regio urogenitalis)

Urogenital diaphragm (regio urogenitalis)
Urogenital diaphragm (regio urogenitalis)
Urogenital diaphragm (regio urogenitalis)
Urogenital diaphragm (regio urogenitalis)

The pelvic diaphragm / anal triangle (region analis)

Pelvic diaphragm / anal triangle (region analis)
Pelvic diaphragm / anal triangle (region analis)
Pelvic diaphragm / anal triangle (region analis)
Pelvic diaphragm / anal triangle (region analis)

Next, we will cover the muscles of the pelvic diaphragm. The rectum passes through the pelvic diaphragm in both men and women.

The muscles of the pelvic diaphragm are divided into superficial and deep.

The superficial muscles include the following:

The external anal sphincter (m. sphincter ani externus)

External anal sphincter (m. sphincter ani externus)
External anal sphincter (m. sphincter ani externus)
External anal sphincter (m. sphincter ani externus)
External anal sphincter (m. sphincter ani externus)
The external anal sphincter
(m. sphincter ani externus)

Origin: skin in the anus region, as well as on the apex of the coccyx (deeper fasciculi)

Insertion: perineal body

Function: narrows / squeezes the anus, strengthens the perineal body

Innervation: inferior anal branch of the pudendal nerve (S2-S4)

Blood supply: inferior rectal artery, perineal artery

The deep muscles include:

The levator ani muscle (m. levator ani)

levator ani muscle (m. levator ani)
levator ani muscle (m. levator ani)
levator ani muscle (m. levator ani)
levator ani muscle (m. levator ani)
The levator ani muscle
(m. levator ani)

Origin:

Puborectal part: posterior surface of the pubis body

Pubococcygeal part: posterior surface of the pubis body (lateral to the part described previously)

Iliococcygeal part: ischial spine, tendinous arch of the internal obturator fascia

Insertion: the muscle covers the rectum, forming a loop, and is partially woven into the wall of the urinary bladder; in men, it is also woven into the prostate, and in women — into the wall of the vagina

Function: promotes retention of urine and feces, strengthens the pelvic floor, and increases intra-abdominal pressure. In women, it also narrows the vaginal opening

Innervation: nerve of the levator ani muscle (S4), inferior anal nerves (S3-S4), coccygeal plexus

Blood supply: inferior gluteal artery

The coccygeus muscle (m. coccygeus)

Coccygeus muscle (m. coccygeus)
Coccygeus muscle (m. coccygeus)
Coccygeus muscle (m. coccygeus)
Coccygeus muscle (m. coccygeus)
The coccygeus muscle
(m. coccygeus)

Origin: ischial spine

Insertion: inferior part of the sacrum, coccyx

Function: strengthens the pelvic floor, holds the coccyx

Innervation: anterior branches of spinal nerves (S4, S5)

Blood supply: deep pudendal artery, perineal artery

Dictionary

Muscles of the perineum. Diaphragm of the pelvis.

Perineum
perineum
Central tendon
centrum tendineum perinei
Perineal raphe
raphe perinei
Urogenital diaphragm
regio urogenitalis
Pelvic diaphragm / anal triangle
regioanalis
External anal sphincter
m. sphincter ani externus
Levator ani muscle
m. levator ani
Coccygeus muscle
m. coccygeus
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