Pelvis Flashcards
Question Bank
Pelvic inlet boundaries
Bounded by pubic creast, pectineal line of pubis, arcuate line of ilium, ala of sacrum and posteriorly by sacral promontory
What muscles attach to the pubic crest?
Rectus abdominis External oblique aponeurosis
What attaches to the ilium
Rectus femoris Quadratus lumborum Lat dorsi
What transmits via the greater sciatic foramen
Above piriformis: superior gluteal nerve and vessels Below piriformis: inferior gluteal nerve and vessels, pudendal nerve and vessels, n to obturator internus, sciatic nerve
Structures passing through the lesser sciatic foramen
Medially: pudendal nerve, internal pudendal vessels Laterally: tendon of obturator internus, nerve to obturator internus
Borders of the lesser sciatic foramen
Lesser sciatic notch Sacrospinous lig Sacrotuberous lig
Ischial spine
Gives rise to coccygeus, superior gemellus m., attachment of sacrospinous ligament, n to obturator internus, pudendal n crosses behind
Borders of the inguinal canal
Internal oblique lateral part of anterior wall, fascia transversalis + conjoint tendon forms posterior wall, lacunar ligament is medial part of the floor
Where is the spermatic cord in relation to the lacunar ligament?
In erect position, spermatic cord is on its superoanterior surface
What is the conjoint tendon and where does it run?
Formed partly from aponeurotic fibres of the transversus muscle Attaches to superior pubic ramus, along pectineal line with a free inferolateral border
What area does the superficial inguinal lymph nodes drain?
Subcut tissues of the back below the waist, gluteal region and anal canal
Which branches of the lumbar plexus appear at the medial border of psoas major?
Obturator nerve Lumbosacral trunk
Which nerve supplies the skin over the root of the penis?
Ilioinguinal nerve
Define the lumbosacral trunk
Contributes to the sacral plexus, first appears medial to the psoas major, contributes fibres to the cutaneous nerve
What spinal levels contribute to the obturator nerve?
Anterior divisions of ventral rami of L2, L3 and L4
Where does the obturator nerve run?
Lies above the obturator vessles on lateral wall of pelvis, lateral to ureter thn pierces the medial border of the psoas
What does the obturator nerve supply?
Gracilis muscle, knee and hip joints. The posterior branch supplies the obturator externus muscle
What is an obturator hernia?
Rare hernia of the pelvic floor where pelvic or abdominal contents protrude through the obturator foramen. High mortality and morbidity. More common in multiparous elderly women who have lost a lot of weight
Where does the pain from an obturator hernia go?
Pain is referred to the medial thigh because the obturator nerve straddles the adductor brevis and supplies medial thigh sensation
Which nerve is the motor supply of the levator ani
Pudendal nerve on perineal surface and perineal branches of S3 + S4
Another name for nervi erigentes
Splanchnic nerves
What are the splanchnic nerves?
Arise from sacral spinal nerves S2, S3 and S4 to provide parasympathetic innervation to the hindgut
Define the urogenital diaphragm
Contains the external urethral spincter and deep transverse perineal muscles. Lies above the perineal membrane + contained by the deep perineal pouch
What is the least mobile part of the bladder and why?
The trigone, because it is fixed on top of the prostate by the urethra
What is the most common source of major bleeding during radical prostatectomy?
Dorsal vein complex of the penis
What lines the ductus deferens?
Stereo-ciliated columnar epithelium
Where do the ejaculatory ducts open?
Sides of the urethral crest
What is another name for mesonephric ducts
Wolffian ducts
What are Wolffian ducts
Paired embryonic tubules that drain the primitive kidney to the cloaca
What do the Wolffian ducts become in men
Rete testis, efferent ducts, epididymis, ductus deferens and seminal vesicles
Where does the prostate form from
Urogenital sinus
What do the Wolffian ducts become in women?
Epoophoron + skene’s glands (if remnant persists lateral to the vaginal wall - Gartner’s duct or cyst)
What artery supplies the corpus cavernosum
Deep artery to the penis
What is the venous drainage of the corpus cavernosum
Prostatic venous plexus
What encloses the corpus cavernosum
Tunica albuginea
When do the testis descend
Descend to the deep inguinal ring by 7 months in the male foetus
What LNs drain the testes
Para-aortic lymph nodes
What is the arterial supply of the testis
Testicular artery however the artery of the vas which anastomosis with the testicular artery is very small - so limited supply if ligation of the testicular artery occurs
What is the pathophys of varicocoele
It is a dilation of the pampiniform plexus (due to incompetence in the gonadal vein)
Treatment of varicocoele
High ligation of gonadal vein
Frequency & laterality of varicocoele
15% of young men. most frequently on the left side
Why would you perform a renal USS in varicocoele?
Occasionally may result from obstruction of the renal vein by RCC (L>R)
What is the effectiveness of vasectomy?
1 in 5000 risk of spontaneous recanalization of the vas
What is the derivative of the internal and external spermatic fascia?
Internal: transversalis fascia External: external oblique
What is the derivative of the cremaster muscle?
Internal oblique
Contents of the spermatic cord
Ductus deferens Obliterated processus vaginalis Testicular artery Sympathetic fibres from T10 Genital branch of the genitofemoral nerve
What innervates the anterior 1/3 of the scrotum
L1
What contributes to the cutaneous nerve of the scrotum
Scrotal branches of the perineal nerve, ilioinguinal nerve
Which sphincter provides urinary continence?
Spincter externus
What pierces the perineal membrane in med?
Ducts of the bulbo-urethral glands
Contents of the superficial perineal pouch
Ischio-cavernosus muscle, enclosed by superficial perineal fascia of Colles, contains vestibular glands, extends in front of symphysis pubis
Contents of the deep perineal pouch in males
Bulbo-urethral glands Internal pudenal artery Membranous urethra sphincter urethrae muscle
What is the broad ligament
A peritoneal fold which attaches the whole body of the uterus to the lateral wall of the pelvis
What does the broad ligament contain?
Ureter, uterine artery, inferior hypogastric plexus
What is the broad ligament
A peritoneal fold which attaches the whole body of the uterus to the lateral wall of the pelvis
What does the broad ligament contain?
Ureter, uterine artery, inferior hypogastric plexus
Lymph drainage of the ovary
Follows the ovarian artery to its origin at L2 (Para-aortic lymph nodes)
Why can ovarian pain refer the medial thigh
Because the obturator nerve supplies the parietal peritoneum adjacent to the ovary
Lymph drainage of the uterus
Some to superficial inguinal lymph nodes
Blood supply of the uterus
Uterine artery, vaginal artery and ovarian artery. Receives branch from the inferior hypogastric plexus with sympathetic elements being vasoconstrictor
Supply of the uterine artery
Anterior division of the internal iliac artery, crosses above the ureter in the broad ligament, supplies the vaginal vault and medial part of Fallopian tube
What is the embryological origin of the Fallopian tube
Paramesonephric duct
What part of the rectum is covered in peritoneum?
Upper 2/3rds of the anterior surface and upper 1/3 of the lateral surface
Another name for bulbourethral glands?
Cowper’s glands
What part of the rectum is covered in peritoneum?
Upper 2/3rds of the anterior surface and upper 1/3 of the lateral surface
What separates the anterior wall of the rectum from the prostate and seminal veiscles
Fascia of Denonvilliers
What folds does the rectum have
Permanent folds running transversely - mucous membrane and circular smooth muscle - but NO taeniae coli
What suspends the rectum in the hollow of the sacrum?
Fascia of Waldeyer
What separates the distended rectum from the sacrum and coccyx?
Ganglion impar, sacral part of the sympathetic trunk and piriformis
What separates the anterior wall of the rectum from the prostate and seminal veiscles
Fascia of Denonvilliers
What folds does the rectum have
Permanent folds running transversely - mucous membrane and circular smooth muscle - but NO taeniae coli
What suspends the rectum in the hollow of the sacrum?
Fascia of Waldeyer
What separates the distended rectum from the sacrum and coccyx?
Ganglion impar, sacral part of the sympathetic trunk and piriformis
Another name for the ganglion impar
Walther’s ganglion
What are possible consequences of APR and why
Failure of erection (parasympathetic)
Failure of ejaculation (sympathetic fibres T11-T12)
What supplies the superior rectal artery?
The inferior mesenteric artery
What is contained within the lateral ligament of the rectum?
Middle rectal artery
Where do anal valves lie?
Above the smooth surfaced area of the anal canal, at the lower end of the anal colums. Not felt on PR exam
What is the bony attachment of the internal sphincter?
It doesnt have one
Where is the ischio-rectal fossa in relation to the urogenital diaphragm?
The ischio- rectal fossa extends anteriorly above the urogenital diaphragm BECAUSE the ischio-rectal fossa extends forwards below the levator ani muscles which are attached to the body of the pubic bone above the level of the urogenital diaphragm
