Ach: Perineum Flashcards Preview

GI- Week 3 > Ach: Perineum > Flashcards

Flashcards in Ach: Perineum Deck (59):

Where is the perineum located?

INFERIOR to the pelvic diaphragm in the pelvic outlet


What does structures does the perineum contain?

external genitalia

terminal portions of urogenital system and GI tract


What are the boundaries of the pelvic outlet?

Pubic arch: tip of the coccyx

Lateral: Inferior ramus of pubis and ischium and sacrotuberous ligaments


What is the UG triangle?

ANTERIOR to the transverse line


What is the anal triangle?

POSTERIOR to the transverse line


Where is an important support for the pelvic floor?

the central tendon of the perineum is a point where several muscles of the perineum insert


What are the two layers of the superficial perineal fascia?

1. Superficial fatty layer

2. Membranous layer/colles fascia (continuous w/ Scarpa's in the abdomen)


The superficial fatty layer of fascia is continuous with....

fascia in the:


How does the superficial fatty layer differ in the female body from the male?

F: continues into the labia majora and inserts near the perineal body

M: fatty layer less in UG triangle, continues around penis into scrotum where fat is replaced by smooth muscle (dartos muscle)


Where does the membranous layer of the superficial perineal fascia attach?

Ischiopubic rami laterally

Fascia lata of hte ghigh

posterior border of the UG diaphrgam


What happens to the membranous layer in the male?

It fuses w/ the superficial fatty layer anteriorly--> dartos fascia that surrounds the scrotum and the penis

the fat is replaced by smooth muscle called the dartos muscle


What is colles fascia?

separates the dartos fascia at the base of the penis and continues to the UG diaphragm


The superficial perineal fascia is an extension of...

the superficial fascia of the anterior abdominal wall


What are the two layers of the deep perineal fascia?

1. Deep perineal (gallaudet's fascia)

2. deep fascial layer (buck's fascia)


What does the deep perineal fascia consist of?

Consists of the investing layer (gallaudet's fascia) surrounding muscles in the superficial perineal pouch and the deep fascial layer (buck's fascia) over the erectile bodies of the penis


What is the perineal membrane?

thin sheet of deep fascia

attached to the ischiopubic rami laterally

Pierced by the urethra in the male and the rethra and vagina in the female


What are the two pouches in the UG triangle?

1. Superficial perineal space (between the membranous layer of the superficial fascia and the perineal membrane)

2. Deep perineal space (opens superiorly and is bounded below the perineal membrane)


What is found in the superficial perineal pouch?

1. Erectile bodies
2. Superficial trnasverse perineal muscle
3. vessels and nerves of muscles
4. Greater vestibular glands in the female


What are the erectile bodies?

bulb of the penis
bulb of the clitoris


What muscles cover the crura and the bulb?




What does the superficial transverse perineal muscle do?

stabilizes perineal body


What vessels /nerves supply the superficial perineal pouch?

internal pudendal artery

pudendal nerve


What is essential for the integrity of the pelvic floor?

perineal body/central tendon of the perineum that's a midline fibromuscular mass between the UG and anal triangles


Where is located in the deep perineal pouch?

1. deep transverse perineal muscle
2. sphincter uretrhae muscle
3. compressor urethrae muscle
4. urethra
5. internal pudendal vessels, pudendal nerves and their branches


What penetrates hte deep perineal pouch in the female?



What glands are located in the deep perineal pouch in hte male?

bulbourethral (cowpers)


The deep perineal pouch and its contents is also called the....



What is the penis composed of?

3 cylindrical bodies of erectile tissue

enclosed by dense tissue

forms capsule called tunica albuginea


What is the corpora cavernosa in the penis?

begins as the crura of the penis

located ventrally dorsally


What does hte corpus spongiosum begin as and where is it located?

as the BULB of the penis that expands distally to form the glans penis.

located ventrally


Where is the root of hte penis found?

superficial perineal space


How long is the urethra?

20 cm


What are three portions of the urethra?

1) prostatic: penetrates prostate
2) membranous: that portion which traverses the deep perineal pouch and is surrounded by the sphincter urethrae muscle.
3) spongy or penile: that portion found in the corpus spongiosum.


What fascia covers the penis?

1. Superficial

2. Deep (continuous w/ the external spermatic fascia in the scrotum and the suspensory ligament of the penis)


What is the mons pubis?

eminence over the pubic bone (mons veneris)


what are the labia majora and minora?

outer and inner folds of skin that extend posteriorly from the mons


What is the clitoris composed of?

erectile tissue composed of two CRURA (coversed by ischiocavernosus muscles), a body and a glans


Does the clitoris contain corpus spongiosum?

NO b/c it's NOT traversed by the urethra


What are the frenulum and the prepuce?

Parts of the clitoris that are parts of the labia minora that pass posterior and anterior to the clitoris


What is the vestiblue?

area posterior to clitoris and between labia minora; openings of vagina, urethra, and greater vestibular glands.


What is the hymen?

membrane of variable size and found partly blocking the vaginal orifice.


What are the bulbs of the vestibule?

two masses of erectile tissue that lie along the vaginal orifice; covered with bulbospongiosus muscles


What is the ischioanal fossae?

A wedge-shaped area on either side of the rectum located between the skin and the pelvic diaphragm


What are the boundaries of the anal triangle?

1) laterally: obturator internus and fascia

2) medially: anal canal

3) posteriorly: sacrotuberous ligament and gluteus maximus

4) anteriorly: base of UG diaphragm and fascia

5) superiorly: levator ani


What forms the pudendal canal and what does it contain?

obturator internus fascia

internal pudendal artery and the pudendal nerve


What are the branches of the internal pudendal artery?

inferior rectal artery

perineal artery


What forms the sacral plexus?

pudendal nerve (S2,3,4)


Where is the pudendal nerve lcoated?

The pudendal nerve passes through the greater sciatic foramen, crosses the ischial spine and enters the perineum through the lesser sciatic foramen with the internal pudendal artery. It then enters the pudendal canal, gives off the inferior rectal nerve and terminates as the perineal nerve and the dorsal nerve of the penis (clitoris).


What nerve supplies the external anal sphincter?

inferior rectal nerve


What nerve supplies all the muscles of the perineum and gives off a superficial scrotal or labial nerve to supply the posterior scrotum or labium?

perineal nerve (terminal branch of pudendal)


What nerve pierces the perineal membrane and runs deep to the deep fascia on the dorsum of the penis or clitoris to supply the skin, prepuce, and glans?

Dorsal nerve of the penis/clitoris (terminal branch of pudendal)


What's a straddle injury?

bruising to tearing to nerve damage to fracture of pubic rami


How does bicycling cause erectile dysfunction?

poor seat design puts pressure on pudendal nerve and artery branches>

Numbness or pain after a long ride

Altered sensation of micturition, defecation and ejaculation
c. Chronic pressure can lead to localized atherosclerosis of pudendal vessels, compromised blood supply and erectile dysfunction.


How does chronic pressure on the pudendal nerve lead to erectile dysfunction?

It can cause localized atherosclerosis of pudendal vessels, compromised blood supply and erectile dysfunction


Where does the urine go if a ruptured urethra does NOT penetrate Buck's fascia?

confined to penis


What happens to the urine if a urethral rupture does perforate buck's fascia?

Urine will spread beneath colles fascia in the penis, scrotum, anterior abdominal wall, but NOT the thigh b/c of the attachment of this fascia to the fascia lata


What is an episiotomy?

prevent tears of the perineum and to ease delivery of the fetus, a small relaxing incision is made in the perineum, either directly posterior to the opening of the vagina or somewhat lateral. Midline incisions heal better


What is a pudendal nerve block?

provides anesthesia to the skin, muscles and deeper structures of the perineum to relieve pain from childbirth and permit episiotomy.

Also, a block will produce relaxation of all the perineal muscles and reduce the possibility of laceration.


Where is a pudendal nerve block given?

Feel for the ischial spine to locate the pudendal nerve