Pelvic anatomy Flashcards
What are the key fascial layers of the anterior abdominal wall?
Superficial split into two layers:
-> Campers fascia -> fatty layer
-> Scarpas fascia -> membranous layer
Deep: transversalis fascia -> deep to transveraslis abdominus muscle
What are the continuations of scarpas fascia?
Attachment to fascia lata - anterior thigh - ends fascial compartment.
Continues as the superficial penile fascia
Superficial perineal fascia (colles fascia)
And the dartos fascia - continuation of colles fascia in males
What structure are the external genitalis anchored to?
The urogenital diaphragm/the perineal membrane
What are the different parts of the male urethra?
Preprostatic
Prostatic
Membranous (through bulbourethral glands)
Spongy (penile)
What are the consequences of rupture of the spongy urethra from a saddle injury?
Blood and urine leakage intot he superficial perineal pouch
Can not spread into the deep perineal pouch due to the perineal membrane
Presents with swelling in the scrotum, penis, inferior abdominal wall
Can not pass into anorectal triangle due to fusion of perineal fascia with the perineal membrane.
Can not pass into thighs due to fusion with the fascia lata.
Characteristic butterfly bruising
What are the consequences of rupture of the membranous urethra?
Extravasation of blood and urine into the deep perineal space as deep to the perineal membrane
Fluid may pass superiorly through the urogenital hiatus and distribute intraperitoneally around the prostate, bladder and anterior rectal wall.
What are the layers that form the rectus sheath?
Split happens at the level of the umbilicus -> the arcuate line - half way between the umbilicus and pubic symphysis -> where the posterior rectus sheath ends
What are some important folds in the peritoneum on the internal abdominal wall?
Median umbilical fold -> midline -> remnant of the urachus.
Medial umbilical fold - obilateral umbilical artery
Lateral umbilical fold -> peritoneum over the inferior epigastric artery.
What is the clinical importance of the lateral umbilical fold?
Overlies the inferior epigastric vein
lateral to this = indirect inguinal hernia
Medial to this = direct inguinal hernia
What is the innervation of the anterior abdominal wall?
Intercostal nerves T7 to T11
Subcostal nerve T12
What are some key surface landmarks for innervation of the abdomen?
Xiphoid process - T5 and T6
Umbilicus - T10
Ilioinguinal area - T1
What are the basics of the descent of the testes?
Are retroperitoneal organs
The gubemaculum helps pull the testes through the inguinal canal into the scrotum.
Pulls layers of the abdominal wall with
Some of peritoneum is pulled with (processes vaginalis) which eventually pinches off to form the tunica vaginalis.
What are the key layers of the spermatic cord?
External spermatic fascia -> from EOA
Cremastaric fascia -> IOA
Internal spermatic fascia -> from Transveraslis fascia
Tunica vaginalis -> peritoneum
What is the blood supply to the testes?
Testicular arteries -> branch from AAA
Contributions from the internal iliac -> deferential
External iliac -> cremasteric
What is the venous drainage of the testes?
Pampiform plexus
Into the vesicular vein (Internal iliac vein) or the testicular vein (AAA for right and left renal vein for left)
What are the key nerves related to the spermatic cord?
Ilioinguinal nerve - passes through inguinal canal on the surface of the spermatic cord
The genitofemoral nerve - genital branch passes within the spermatic cord.
What forms the floor of the inguinal canal?
The inguinal ligament (extension of EO aponeurosis)
With the lacunar ligament medially
What forms the anterior wall of the inguinal canal?
The aponeuoris of external oblique
Reinforced on lateral 3rd by muscular fibres of IOM.
Superficial inguinal ring is here as a weakness in EO
What forms the roof of the inguinal canal?
Arching fibres of the internal oblique and transverse abdominus muscles -> join together to form the conjoint tendon
What forms the posterior wall of the inguinal canal?
The transversalis fascia
Reinforced by the conjoint tendon medially.
Femoral hernias are found in the femoral canal.
What is this relevant to the femoral ring and sheath?
Ring = opening of triangle superiorly
Sheath - specific part of this containing the femoral artery, vein and canal, and the femoral branch of the genitofemoral nerve
Canal - part of sheath for lymph nodes and expansion of veins (potential space)
What structure do femoral hernias often protrude out of to escape the femoral sheath?
The saphena-varinx
What is a spigelian hernia?
Rare hernia
Protrusion between the rectus abdominus and the lateral abdominal muscles - the linea semilunaris
What is a testicular torsion?
Surgical emergency
Twisting of the spermatic cord and content - occludes blood flow and venous drainage
Sudden onset severe unilateral testicular pain
Swollen and tender testicle and absent cremasteric reflex
What is phimosis?
Disorder of the foreskin of the penis - inability to retract over the glans - common in infants and young children -> resolves with puberty
Reoccurs in pathology in adults
Can’t be pulled back.
What is paraphimosis?
When a retracted foreskin can’t be replaced to its original position - leading to venous congestion and possible ischaemia of the gland penis if no corrected.
What are the problems with an undescended testes?
Also called cryptochidism
Present at birth
Two thirds spontaneously descend by first year of life
May need surgical fixation -> as if remain undescended is a risk for testicular cancer
What is a hydrocele?
Fluid collection around the testicle usually from an incomplete obliteration of the processes vaginalis during normal testicular descent
Scrotal swelling and discomfort (tends not to be red)
Increased risk of an indirect inguinal hernia
What is a varicocele?
Enlargement of the scrotal veins
Asymptomatic -> may cause aching or heaviness in scrotum
Contribute to infertility
