perineum Flashcards
what is the perineal membrane?
a triangular fascia under the muscles of the pelvic diaphragm (levator ani and coccygeus)
what is on the above of the perineal membrane?
the deep perineal pouch/space
what is above the deep perineal pouch?
the urogenital hiatus of the puborectal muscle
what are the 4 muscles of the deep perineal pouch?
external ureteral sphincter, the deep transverse perineal muscle, the compressor urethrae muscle, the sphincter ureterovaginalis muscle
what is the origin of the EUS?
inferior ramus of the pubis
what is the insertion of the EUS?
around the membranous layer of the ureter
what is the innervation of the DPP muscles?
the pudendal nerves
what is the function of the EUS?
compresses and relaxes for micturition
what is the origin of the deep transverse perineal muscle?
medial ramus of ischium
what is the insertion of the deep transverse perineal muscle?
perineal body
what is the function of the DVP muscle?
stabilizing the perineal body
what is the origin of the compressor urethrae?
ischiopubic ramus
what is the insertion of the compressor urethrae?
each other at the anterior of vagina
what is the function of the compressor urethrae?
accessory urethral sphincter
what is the origin of the uretrovaginal sphincter?
the perineal body
what is the insertion of the uretrovaginal sphincter?
each other laterally at the anterior of vagina
what forms the roof of the perineum?
the levator ani
which bone compartmentalizes the perineum?
the imaginary line between ischial tuberosities divide the perineum into the anterior urogenital and posterior anal triangle
What is the central tendon called?
The perineal body
Where can the ischial tuberosities be palpated?
At the crease of the gluteal region.
Where can the symphysis pubis be palpated?
For males immediately superior to the penis, for females deep to the mons pubis
Where can the coccyx be palpated?
Posterior to the anal aperture.
What is the ischioanal fossa?
The levator ani joining the perineal membrane leaves a margin (fossa) that enables structures or infections to occur.
What makes up the lateral wall of the ischioanal fossa?
The obturator internus, the sacrotuberous ligament, and the ischium.
What is on the medial wall of the ischioanal fossa?
The levator ani.
What is on the superior of the ischioanal fossa?
The arcus tendon.
What is the major muscle of the anal triangle and its compartments?
The external anal sphincter, the deep, superficial, and subcutaneous compartments.
What is the morphology of the deep part of the external anal sphincter and its innervations?
Ring shaped muscle that binds the superior anal canal and is fused with the levator ani and is innervated by S2-S3 and direct branches from S4.
What is the morphology of the superficial part of the external anal sphincter and its attachments?
A ring-shaped muscle that wraps the inferior anal canal and attaches to the anococcygeus (posteriorly) and the perineal body (anteriorly).
What is the morphology of the subcutaneous part of the external anal sphincter?
A flattened disc that surround the anal aperture beneath the skin.
What supportive membrane does the urogenital triangle contain that the anal triangle doesn’t?
The perineal membrane.
What is a pouch only located on the urogenital triangle?
The superficial perineal pouch.
What is the ligament that suspends the body of the penis?
The fundiform ligament of the penis (attaches to the linea alba) and the suspensory ligament of the penis (attaches to the superior of symphysis pubis).
Explain the erectile tissues of the female genitalia!
The vestibular bulbs are located on each side of the urethral opening.
They both anteriorly attach to the glans clitoris by a ligament.
Explain the erectile tissues of the male genitalia!
The bulbs of the penis are one (the corpus spongiosum) and then attach as the ventral part of the penis and expands at the distal aspect to form the glans of the penis.
What is the root of the clitoris?
The 2 crus made by the attached aspects of the corpus spongiosum.
What forms the body of the clitoris?
The unattached part of the corpus cavernosum.
What forms the root of the penis?
The 2 attached crus of the penis (corpus cavernosum) and the bulb of the penis.
What forms the body of the penis?
The body of the penis is formed by the corpus cavernosum and the corpus
What is the origin of the superficial transverse perineal muscle?
The ischial tuberosity and ramus.
What is the insertion of the superficial transverse perineal muscle?
The perineal body.
What is the function of the STP?
Stabilizes the perineum.
What is the innervation of the perineal muscles?
S2-S4
What is the origin of the ischiocavernous muscle?
The ischial tuberosity and ramus.
What is the attachment of the ischiocavernous muscle?
The crus
What is the function of the ischiocavernous muscle?
Enables blood flow from the crura to the body of penis/clitoris.
What is the origin of the bulbospongious muscle?
The perineal body and midline raphe (for males).
What is the attachment of the bulbospongious muscle?
In women: bulb of
vestibule, perineal
membrane, body of clitoris,
and corpus cavernosum
In men: bulbospongiosus,
perineal membrane,
corpus cavernosum
What is the function of the bulbospongious muscle for males?
Secretion of residual urine and ejaculation
What is the function of the bulbospongious muscle for females?
Moves blood from attached parts of the clitoris and from the penis body to the glans.
What is the difference between the bulb of vestibule and the bulbourethral gland’s position?
The GVG is located in the SPP, while the BU is located in the DPP.
What does the Colles’ fascia attach to posteriorly?
The perineal membrane.
What does the Colles’ fascia attach to laterally?
The ischiopubic ramus
True or false
The Colles’ fascia doesn’t wrap around the penis and clitoris!
False
True or false
The Colles’ fascia fuses with the anterior abdominal wall!
True
Explain!
The superficial pouch’s infections can be tracked onto the lower abdominal fascia.
the covering of the superficial pouch, in this case the Colles’ fascia is attached directly to the lower abdomen (Scarpa’s fascia)
Where does the pudendal nerve travel through?
The pudendal canal which is a tubular shaped structure in the lateral wall of the ischio-anal fossa formed by the fascia that covers the obturator internus muscle.
Where are the common spots of urethral rupture?
Proximal spongy urethra below the perineal membrane and the prostatomembranous junction.
What structures flow along with the pudendal nerve?
The internal pudendal artery and its veins.
What are the 3 branches of the pudendal nerve?
The inferior rectal, the perineal nerve, and the dorsal penis nerve
What is the course of the inferior rectal nerve?
It goes through the fascia of obturator internus that covers the pudendal nerve to medially attach to the rectum.
What is the course of the perineal nerve?
It continues through the fascia and supplies the muscles of the deep and superficial perineal pouch
What is the course of the dorsal penis/clitoris nerve?
The dorsal penis nerve courses the lateral margins of the pouch and then exist through the perineal membrane under the symphysis pubis to supply the dorsal side of the penis/clitoris.
What are the branches of the internal pudendal artery?
The perineal artery, the inferior rectal artery, and the terminal branches of the internal pudendal artery.
What are the branches of the terminal internal pudendal artery?
The artery of the bulb of the penis that branches to supply the bulbourethral gland and pierces the perineum to supply the corpus spongiosum.
The urethral artery that penetrates the perineal membrane to supply penile urethra and the glans
The deep artery of penis that penetrates the perineal membrane and supplies the crus and corpus cavernosum and the dorsal artery of penis that penetrates the anterior margin of the perineal membrane to the dorsal penis.
What is the course of the dorsal penile artery?
It is located medial to the dorsal nerve and supplies the glans penis and superficial penile tissues.
