Pelvis and Perineum Flashcards
What are the three divisions of the puedendal nerve?
Inferior Rectal nerve
Perineal nerve
Dorsal nerve of penis/ clitoris
What are the two terminal branches of the puedendal nerve?
perineal nerve, and the dorsal nerve of the penis or the dorsal nerve of the clitoris
Which structures pass through the greater and lesser sciatic foramina?
Structures passing through the lesser and greater sciatic foramina (medial to lateral): PIN
Pudendal nerve
Internal pudendal artery
Nerve to obturator internus
From which embryological structure is the ureter derived?
mesonephric duct
What is the nerve root value of the external urethral sphincter?
The external urethral sphincter is innervated by branches of the pudendal nerve- S2, S3, S4.
What is the difference between the male and female urethra?
The female urethra is shorter and more acutely angulated than the male urethra.
what are the four parts of the male urethra?
- pre-prostatic urethra
- prostatic urethra
- membranous urethra
- penile urethra
what is the widest part of the male urethra?
Prostatic urethra (contains several openings for semen)
what is the narrowest part of the male urethra?
Membranous urethra (surrounded by external sphincter)
which lymph nodes does the ureter drain to?
upper ureter - para-aortic lymph nodes
lower ureter - common iliac nodes
What are the origin nerve roots of puedendal nerve?
Anterior rami of S2-4
what is the path of the puedendal nerve?
posterior to the sacrospinous ligament
What is the motor function of the puedendal nerve?
Levator Ani (IRN)
External anal sphincter (IRN)
Superficial pouch muscles (perineal nerve)
What is the sensory function of the puedendal nerve?
Skin over anal triangle (IRN)
Glans clitoris (dorsal nerve)
General sensation (perineal nerve)
Where does the internal puedendal artery originate and what does it supply?
Originates from the anterior branch of the internal iliac artery
supply erectile tissues/muscles and parts of the rectum and anal canal)
Where do the external pudendal arteries originate and what do they supply
Originate from the femoral artery
Superficial and deep
Supply the clitoris and labia majora
What is the venous drainage of the perineum?
veins in perineum
internal puedendal vein
internal iliac vein
What is deep lymphatic drainage of the female perineum?
internal iliac nodes
what drains to superficial inguinal nodes?
superficial tissues of the genitalia (body and crura of clitoris/labia majora)
what drains to deep inguinal and external iliac nodes?
Glans clitoris, labia minora and terminal end of vagina
which blood vessels are responsible for supplying the rectal stump directly?
superior rectal artery
Middle rectal artery (from the internal iliac)
Inferior rectal artery (from the pudendal vessels)
Venous drainage of the rectum?
Superior rectal vein
Inferior rectal vein
Note the venous drainage is a site of portosystemic anastomosis.
Lymphatic drainage of the rectum?
Mesorectal lymph nodes (superior to dentate line)
Inguinal nodes (inferior to dentate line)
Where does the puedendal canal extend from?
lesser sciatic foramen to the posterior margin of the urogenital diaphragm
(lateral wall of the ischioanal fossa at the inferior margin of the obturator internus muscle.)
What forms the urogenital triangle?
Ischiopubic inferior rami
Ischial tuberosities
A fascial sheet is attached to the sides, forming the inferior fascia of the urogenital diaphragm.
In males what does the superficial perineal pouch contain?
Bulb of penis
Crura of the penis
Superficial transverse perineal muscle
Posterior scrotal arteries
Posterior scrotal nerves
In surgical exploration of the testes what are the layers that will be encountered? (and in what order)
The layers that will be encountered are (in order):
1. Skin
2. Dartos fascia and muscle
3. External spermatic fascia
4. Cremasteric muscle and fascia
5. Internal spermatic fascia
6. Parietal layer of the tunica vaginalis
Some Damned Examiner Called It The Testes (skin dartos external fascia cremaster internal fascia tunica Testes)
What runs through greater sciatic foramen (above piriformis)?
superior gluteal nerve, artery and vein
What runs through greater sciatic foramen (below piriformis)?
sciatic nerve
inferior gluteal nerve, artery, vein
pudendal nerve
internal pudendal artery and vein
posterior femoral cutaneous nerve
nerve to obturator interns and gemellus superior
nerve to quadrates femoris and gemellus inferior
What transmits between gap between inguinal ligament and pelvic bone?
psoas major, iliacus, pectineous
femoral artery, fem vein
lymphatics
femoral branch of genitofemoral nerve
lateral cutaneous nerve of thigh
femoral nerve
Mucles în deep gluteal compartment?
Piriformis
Obturator internis
Superior gamellus
Inferior gamellus
Quadratus femoris
which structure is most important in supporting the uterus?
central perineal tendon
What is the lymphatic drainage the spongy urethra and the glans penis?
deep inguinal
What is the lymphatic drainage of the prostatic and membranous urethra?
internal iliac nodes
which nerve is the primary source of innervation to the anterior scrotal skin?
ilioinguinal
what are the boundaries of the superficial perineal pouch?
superficially: superficial perineal fascia
deep: perineal membrane (inferior fascia of the urogenital diaphragm)
laterally: ischiopubic ramus
Contents of the superficial perineal pouch in males?
Bulb of penis
Crura of the penis
Superficial transverse perineal muscle
Posterior scrotal arteries
Posterior scrotal nerves
Boundaries of the deep perineal pouch?
inferiorly: perineal membrane, also known as the inferior fascia of the urogenital diaphragm
superiorly: superior fascia of the urogenital diaphragm
Contents of superficial perineal pouch in females?
- greater vestibular glands (Bartholin glands)
- bulbospongiosus muscle: separated by the urethra and vagina in the midline and covers the bulb of the vestibule
-paired ischiocavernosus muscles: tenses the vagina during orgasm
-perineal body
-paired superficial transverse perineal muscles
-crura of the clitoris
Contents of the deep perineal pouch in females?
- proximal urethra
- deep transverse perineal muscles
- compressor urethrae muscle
- urethrovaginalis muscle
- sphincter urethrae
- internal pudendal vessels
- dorsal nerve of clitoris
Contents of deep perineal pouch in males?
- membranous urethra
- deep transverse perineal muscles
- sphincter urethrae
- paired bulbourethral glands (Cowper’s glands).
- internal pudendal vessels
- dorsal nerve of the penis
Which lymph nodes drain the area below the dentate line?
inguinal
which lymph nodes drain the area above the dentate line?
Mesorectal lymph nodes
Which parts of the rectum are extra-peritoneal?
Posterior upper third
Posterior and lateral middle third
Whole lower third
which fascial layers surround the rectum?
Anterior: fascia of Denonvilliers
Posterior: Waldeyers fascia
