What muscles contribute to the formation of the perineal body?
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Levator ani, deep and superficial transverse perineal muscles, bulbospongiosus muscle, and external anal sphincter.
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What muscles contribute to the formation of the perineal body?
Levator ani, deep and superficial transverse perineal muscles, bulbospongiosus muscle, and external anal sphincter.
What is the perineal body?
An irregular fibromuscular mass.
In what position should the perineal body be for correct anatomical alignment?
Horizontal.
What is extravasation of urine?
An abnormal collection of urine in other cavities due to urethral interruption.
What is the primary function of the greater vestibular glands?
To produce mucous secretions that function as a lubricant during sexual arousal.
What is the superior boundary of the deep perineal pouch?
Inferior fascia of the pelvic diaphragm.
What does Dr. Wai propose about the anterior recesses of the ischioanal fossae?
They extend forward to the UG triangle above the UG diaphragm.
What is the role of the corpus spongiosum?
It surrounds the urethra and helps maintain its patency during erection.
What structure is associated with the clitoris and is mentioned in the context of the female anatomy?
Suspensory ligament of clitoris.
What happens to urine in the case of penile urethral rupture with damaged Buck’s fascia?
Urine will collect deep to Colles’ fascia in the superficial perineal pouch, as well as in the penis and scrotum, deep to Darto’s fascia.
What is the origin of the Ischiocavernosus muscles?
Internal surfaces of ischial rami and ischial tuberosity.
Where do the ducts of the greater vestibular glands open?
Adjacent to the posterolateral margin of the vaginal orifice.
What is the inferior boundary of the deep perineal pouch?
Perineal membrane.
What muscle covers the greater vestibular glands inferiorly?
Bulbospongiosus muscles.
What anatomical structure do females lack that males have?
An internal urethral sphincter.
What are the greater vestibular glands?
Paired, rounded tubuloacinar glands only present in females.
Why does the female external sphincter not act very effectively as a sphincter for the urethra?
Because it also surrounds the vagina.
Where does urine extravasate in partial urethral rupture above the UG diaphragm?
Into the retropubic space.
What is the arterial supply for the Ischiocavernosus muscles?
Posterior labial/scrotal branches of the perineal artery.
What is Bartholinitis?
Inflammation of the greater vestibular glands due to infection.
What does the superficial transverse perineal muscle originate from?
The internal surfaces of ischial rami and ischial tuberosity.
What is the course of the superficial transverse perineal muscles?
Runs inferior and parallel to the posterior free border of the perineal membrane and joins with its counterpart at the midline.
What is the purpose of the suspensory ligament of the penis?
It supports the penis and attaches it to the pubic symphysis.
What fascia is mentioned as having continuations in the perineal region?
Colles’ fascia.
What is Buck's fascia?
A deep fascia that surrounds the erectile tissues of the penis.
What is Colles' fascia?
The membranous layer of superficial perineal fascia.
What is the action of the superficial transverse perineal muscles?
To stabilize the perineal body to support abdominopelvic viscera.
What forms the superior boundary of the superficial perineal pouch?
Perineal membrane.
What structure is referred to as the scrotal septum?
It divides the scrotum into two compartments.
What is Buck’s fascia associated with?
It surrounds the corpora cavernosa of the penis.
What is the action of the compressor urethrae?
Compresses/constricts the urethra to maintain urinary continence.
Where is the Anal triangle located?
Posterior to the transtubercular line.
What is the origin of the bulbospongiosus muscle in females?
Perineal body.
What is the function of the perineal membrane?
It acts as a central tendon of the perineum.
How do the fibers of the female external sphincter compare to those in males?
They are relatively thin and weak.
Where do the ducts of the bulbourethral glands open?
Into the bulbar part of the penile urethra.
What is the innervation of the Ischiocavernosus muscles?
Muscular (deep) branch of the perineal nerve, a branch of the pudendal nerve (S2 – S4).
What is the function of the perineal membrane?
It provides support and structure to the perineal region.
What glands are present in the deep perineal pouch?
Bulbourethral (Cowper’s) glands (male only).
What happens to the greater vestibular glands during Bartholinitis?
They may enlarge to a diameter of 4-5 cm and become palpable.
What effect can inflamed greater vestibular glands have on surrounding structures?
They may press on the wall of the rectum.
What does the perineal membrane partition in the urogenital triangle?
It partitions the UG triangle into superficial and deep perineal pouches.
What are the components of the urogenital diaphragm?
Deep perineal pouch and two fascial layers: superior (loose) fascia of UG diaphragm.
What is the role of the perineal body?
It serves as an attachment point for several muscles in the perineum.
What does the bulbospongiosus muscle do?
It aids in the expulsion of urine and contributes to erection.
How many apertures does the perineal membrane have in males?
Two apertures: for the deep dorsal vein of the penis and for the urethra.
What are the apertures of the perineal membrane in females?
Three apertures: for the deep dorsal vein of the clitoris, for the urethra, and for the vagina.
Where does the perineal membrane attach laterally?
To the ischio-pubic rami.
What are the two triangles of the perineum?
Urogenital triangle and Anal triangle.
What does the Urogenital triangle contain?
Root of scrotum and penis in males, and the vulva in females.
With which structures does the perineal body blend?
Blends anteriorly with the posterior border of the perineal membrane and superiorly with Denonvilier’s fascia.
What is the insertion of the bulbospongiosus muscle in males?
Perineal membrane, dorsal aspect of corpus spongiosum and corpora cavernosa, and fascia of the bulb of the penis.
Where else can urine spread in the event of a penile urethral rupture?
Urine may also spread to the anterior abdominal wall, deep to the membranous Scarpa’s fascia.
What are the bulbourethral glands?
Pea-sized paired exocrine glands only present in males.
What can cause urethral rupture leading to extravasation of urine?
Force or inflammatory changes.
What anatomical structures are lateral to the greater vestibular glands?
Labia minora.
What muscles are found in the deep perineal pouch?
Sphincter urethrae, deep transverse perineal muscles, sphincter urethrovaginalis (female only), and compressor urethrae (female only).
What is the action of the Ischiocavernosus muscles?
Maintaining erection of the clitoris or penis by compressing outflow veins and pushing blood from the crus into its body.
How might the roof of the deep perineal pouch be more accurately defined?
As a plane passing through the lowest point of the inferior fascia of the pelvic diaphragm, parallel to the perineal membrane.
What structures are mentioned in relation to the deep perineal pouch?
Anterior recess of ischioanal fossa, levator ani, Gallaudet’s fascia, Colles’ fascia, Buck’s fascia.
What does the term 'urogenital diaphragm' refer to?
It is sometimes used in place of 'deep perineal pouch' to describe divisions of the perineal region.
What is the external urethral sphincter responsible for?
It controls the flow of urine through the urethra.
What is Darto's muscle?
Smooth muscle that is a modification of the fatty layer of superficial perineal fascia in the penis and scrotum.
What is the arterial supply for the superficial transverse perineal muscles?
The perineal artery.
What forms the lateral wall of the perineum?
Perineal part of obturator internus and its fascia.
What is the role of the fatty layer of superficial perineal fascia?
It provides cushioning and support to the perineal region.
What is the function of the perineal body?
It serves as an attachment point for several muscles of the perineum.
Which muscles are found in the superficial perineal pouch?
Bulbospongiosus, ischiocavernosus, and superficial transverse perineal muscles.
What glands are found in the female superficial perineal pouch?
Greater vestibular (Bartholin’s) glands.
What is the origin of the bulbospongiosus muscle in males?
Median raphe on the ventral surface of the bulb of the penis and the perineal body.
Which muscles are associated with the perineal body?
Deep transverse perineal muscle and external anal sphincter muscles.
What are the actions of the bulbospongiosus muscle in males?
Support and fix the perineal body, compress the bulb of the penis to expel the last drop of urine/semen, assist erection by compressing outflow via deep perineal vein and pushing blood from bulb to body of penis.
What are the three parts of the female external sphincter?
Sphincter urethrae, sphincter urethrovaginalis, and compressor urethrae.
Will urine spread to the ischioanal fossa in the case of penile urethral rupture?
No, urine will not spread to the ischioanal fossa.
What is the insertion point of the Ischiocavernosus muscles?
Crura of the clitoris or penis.
Where are the bulbourethral glands located in relation to the perineal membrane?
Superior to the perineal membrane.
What is the anatomical relation of the bulbourethral glands to the membranous urethra?
Lateral and posterior to the membranous urethra.
What muscle is not seen in the section due to its position covering the bulb of the vestibule?
The female bulbospongiosus muscle.
What neurovascular tissues are found in the deep perineal pouch?
Internal pudendal vessels, deep branch of perineal nerve, and dorsal nerve of penis/clitoris.
What is the innervation of the perineal body?
Muscular (deep) branch of perineal nerve (a branch of pudendal nerve, S2 – S4).
Why does urine not spread to the thigh during a penile urethral rupture?
Due to the tight attachment of Scarpa’s/Colles’ fascia to the fascia lata of the thigh.
What do the Ischiocavernosus muscles cover?
The crura of the clitoris or penis.
What is the function of the bulbourethral glands?
Production of pre-ejaculatory fluid that aids sperm passage and neutralizes vaginal acidity.
What happens in complete urethral rupture above the UG diaphragm?
Blood and urine extravasate into the retropubic and retrovesical spaces, possibly leading to retroperitoneal hematoma.
What is the bulbous part of the penile urethra in males?
It is part of the male anatomy associated with the urethra.
What is the position of the bulbourethral glands in relation to the prostate?
Inferior to the prostate.
What does the scrotal septum do?
It divides the scrotum into two compartments, each containing a testis.
What is the posterior continuation of the fatty layer of superficial perineal fascia?
Continuous with the ischioanal fat pad in the anal triangle.
What is the origin of the deep transverse perineal muscles?
Internal surfaces of ischial rami.
How do the deep transverse perineal muscles course?
They run superior and parallel to the posterior free margin of the perineal membrane and join with their counterpart at the midline.
Where does the external urethral sphincter originate?
Internal surfaces of ischial rami; in females, some fibers also originate from the compressor urethrae muscle.
What thickens anteriorly to form the transverse perineal ligament?
The perineal membrane.
What is the significance of Denonvilier’s fascia?
It separates the rectum from the prostate in males.
What constitutes the roof of the perineum?
Pelvic diaphragm.
What is the floor of the perineum made of?
Skin and fascia.
How is the perineum divided?
Into two triangles by an imaginary line joining the anterior ends of the ischial tuberosities.
Where is the Urogenital triangle located?
Anterior to the transtubercular line.
How are the two triangles of the perineum oriented?
They are not on the same plane but are placed at an angle to each other.
What happens if the perineal body is torn during childbirth?
The pelvic floor will be significantly weakened.
What is the innervation of the bulbospongiosus muscle?
Muscular (deep) branch of the perineal nerve, a branch of the pudendal nerve (S2 – S4).
What occurs in penile urethral rupture with intact Buck’s fascia?
Urine extravasates into the space between the penis and Buck’s fascia, causing local swelling.
What is the anterior continuation of the deep perineal fascia in males?
Continuous with the deep (Buck’s) fascia of the penis.
How does the deep perineal fascia relate to the external spermatic fascia in males?
It is considered continuous with the external spermatic fascia.
What is the function of the sphincter urethrae muscle?
It controls the flow of urine through the urethra.
How does the fatty layer of superficial perineal fascia differ between males and females?
In males, it is greatly reduced in thickness; in females, it remains thick and makes up the labia majora and mons pubis.
What innervates the superficial transverse perineal muscles?
The muscular (deep) branch of the perineal nerve, a branch of the pudendal nerve (S2 – S4).
What is the inlet of the perineum?
Same as the pelvic outlet.
What is the action of the external urethral sphincter?
Constricts urethra to maintain urinary continence.
What is the anterior continuation of Colles' fascia in males?
Continuous with Darto's fascia of the penis and scrotum, then further continues as Scarpa's fascia of the abdomen.
What does the deep perineal fascia intimately cover?
The muscles of the superficial perineal pouch, including ischiocavernosus, bulbospongiosus, and superficial transverse perineal muscles.
What is the lateral attachment of the deep perineal fascia?
Attaches to the ischiopubic rami.
How does the deep perineal fascia continue anteriorly?
Blends with the inferior edge of the rectus sheath.
What anatomical structures are located posterior and anterior to the perineal body?
Posterior to the vestibule of vagina/bulb of penis and anterior to the anus.
How does the bulbospongiosus muscle course in females?
Courses on each side of the vagina, covering the bulb of the vestibule and greater vestibular glands.
What is the arterial supply of the bulbospongiosus muscle?
Perineal artery.
What are the other structures present in the deep perineal pouch?
Membranous urethra (in male), proximal urethra (in female), and a section of the vagina (in female).
What is the arterial supply for the perineal body?
Perineal artery.
What is the primary action of the perineal body?
Stabilizes perineal body to support abdominopelvic viscera.
What is the posterior attachment of the perineal membrane?
Anchored at the midline to the perineal body.
What forms the inferior boundary of the superficial perineal pouch?
Membranous layer of superficial perineal fascia (Colles’ fascia).
What is the significance of Denonvillier’s fascia?
It separates the prostate from the rectum.
What is the innervation of the sphincter urethrovaginalis?
Muscular (deep) branch of perineal nerve (a branch of pudendal nerve, S2 – S4).
What is the action of the sphincter urethrovaginalis?
Constricts urethra and vagina (aids in maintaining urinary continence).
What is the origin of the compressor urethrae?
Internal surfaces of ischial rami.
What neurovascular structures are present in the superficial perineal pouch?
Branches of the internal pudendal vessels (perineal artery) and branches of the perineal nerve.
Where is the perineal body located in relation to the transtubercular line?
Approximately at the midpoint of the transtubercular line.
How does the bulbospongiosus muscle course in males?
Surrounds the lateral aspect of the bulb of the penis and the proximal part of the body of the penis.
Which muscle group is associated with the pelvic floor and the perineal body?
Levator ani.
Where do the superficial transverse perineal muscles insert?
At the perineal body.
What is the structure of the perineal membrane?
A thin triangular sheet of tough deep fascia.
What is the difference between the UG diaphragm and the deep perineal pouch?
The UG diaphragm includes the deep perineal pouch plus two fascial layers.
What fascia merges superiorly with the external oblique aponeurosis?
Internal spermatic fascia.
What are the attachments of Colles' fascia?
Attaches to the posterior margin of the perineal membrane, perineal body, and fascia lata of the thigh.
What erectile tissue is found in the male superficial perineal pouch?
Root (bulb and crura) of the penis.
What erectile tissue is found in the female superficial perineal pouch?
Clitoris (including its crura) and bulbs of vestibule.
What is the posterior attachment of the deep perineal fascia?
Perineal body.
What does the Anal triangle contain?
The anal canal and the anus.
What is a clinical concern regarding the perineal body during childbirth?
The perineal body is susceptible to tearing.
What is the insertion of the bulbospongiosus muscle in females?
Perineal membrane, pubic arch, and fascia of corpora cavernosa of clitoris.
What fascia blends superiorly with the perineal body?
Denonvilier’s fascia.
What are the actions of the bulbospongiosus muscle in females?
Act as a sphincter for the vagina and assist in the erection of the clitoris and bulb of the vestibule.
