Vasculature of Pelvis Flashcards
What is the major artery of the pelvis?
The internal iliac artery
Where does the internal iliac artery originate?
At bifurcation of the common iliac artery into its internal and external branches
What does the internal iliac artery supply?
It supplies the viscera of the pelvis and perineum and also the musculature of pelvis, perineum and hip joint.
Before the external iliac goes underneath the inguinal ligament, what branch does it give off?
Inferior epigastric artery
What does the inferior epigastric artery supply?
Supplies some of inferior aspect of anterior abdominal wall
As the inferior epigastric passes to the anterior abdominal wall, it gets covered by fascia.
What overlies the inferior epigastric artery?
The lateral umbilical fold (a raised edge of parietal peritoneum)
How is the lateral umbilical fold different to the median and medial umbilical fold?
The contents of the lateral umbilical fold remain functional after birth.
What is the median umbilical fold?
A raised ridge of parietal peritoneum in the deep aspect of the anterior abdominal wall overlying the median umbilical ligament
What is the median umbilical ligament?
The remnant of the embryonic urachus. It extends from the apex of the bladder to the umbilicus, on the deep surface of the anterior abdominal wall
What is the first branch of the internal iliac artery?
Umbilical artery
Where does the umbilical artery course towards?
Anterior wall (towards umbilicus)
What happens as you trace the umbilical artery forward?
Becomes obliterated (no longer needed after birth)
As the umbilical artery passes to the anterior wall, it has a layer of fascia.
What is this fold?
Medial umbilical fold (overlying parietal peritoneum)
Just before the umbilical artery become obliterated, what branches are given off?
Branches suppling superior part of bladder –> superior vesical arteries
What is the next branch of the internal iliac artery?
Obturator artery
Where does the obturator artery course towards?
Going towards defect (hole) in foramen
What is the third branch of the internal iliac artery? How does this differ in males and females?
Uterine artery (females)
Inferior vesicle artery (males)
What does the uterine artery in females supply?
Uterus or vagina (2 branches of uterine)
What does the inferior vesicle artery in males supply?
Prostate or seminal vesicle (2 branches of inferior vesicle)
The middle rectal artery is a branch of the internal iliac (only present in 60%). What does this supply?
Travels medially to supply the distal part of the rectum.
What artery comes off the middle rectal?
Internal pudendal artery
Describe the course of the internal pudendal artery
Loops around sacrospinous ligament into the perineum
Why does the internal pudendal artery loop around?
Bypass muscular sheet (pelvic floor) to get to perineum
What does the internal pudendal artery supply?
All structures of the perineum (branches after entering perineum)
What loops around along with the internal pudendal artery?
Pudendal nerve
How does the pudendal artery exit the pelvis?
Via the greater sciatic foramen
What is the terminal branch of the internal iliac artery?
Inferior (and superior) gluteal artery
How do the inferior and superior gluteal artery leave the pelvis?
Via the greater sciatic foramen
Describe the course of the internal iliac artery
It originates at the bifurcation of the common iliac artery into its internal and external branches at approx L5-S1 (level of pelvic brim)
It descends inferiorly, crossing the pelvic inlet to enter the lesser pelvis. During its descent, it is situated medially to the external iliac vein and obturator nerve.
At the superior border of the greater sciatic foramen, it divides into anterior and posterior trunks.
What are the branches of the anterior trunk of the internal iliac artery?
- Umbilical artery
- Obturator artery
- Uterine artery / inferior vesical artery
- (Vaginal artery)
- Internal pudendal artery
- Middle rectal artery
- Inferior gluteal artery
N.B. there is lots of variation so see where artery attaches to to identify it
Where does the obturator artery pass? What does it supply?
Through the obturator canal (defect) accompanied by the obturator nerve and vein.
It supplies the muscles of the thigh’s adductor region.
What is job of umbilical artery in foetus?
Transports deoxygenated blood from the foetus to the placenta.
As the vaginal artery descends to the vagina, what other branches does it give off?
Supplying additional branches to the inferior bladder and rectum.
Describe the course of the uterine artery
Travels within the cardinal ligament to reach the cervix, where it ascends along the lateral aspect of the uterus
During its course, it crosses the ureters superiorly.
What happens when the uterine artery reaches the origin of the fallopian tubes?
It anastomoses with the ovarian artery.
Describe the course of the middle rectal artery
Travels medially to supply the distal part of the rectum. It also forms anastomoses with the superior rectal artery (derived from the inferior mesenteric) and the inferior rectal artery
Describe the course of the internal pudendal artery
Moves inferiorly to exit the pelvis via the greater sciatic foramen. Accompanied by the pudendal nerve, it then enters the perineum via the lesser sciatic foramen.
What is the main artery responsible for the blood supply to the perineum?
Internal pudendal artery
What is the terminal branch of the anterior trunk of the internal iliac artery?
Inferior gluteal artery
Describe the course of the inferior gluteal artery
It leaves the pelvic cavity via the greater sciatic foramen, emerging inferiorly to the piriformis muscle in the gluteal region.
What are the typical 3 branches of the posterior trunk of the internal iliac artery?
- Iliolumbar artery
- Lateral sacral arteries (superior and inferior)
- Superior gluteal artery
Describe the course of the superior gluteal artery
It exits the pelvic cavity via the greater sciatic foramen, entering the gluteal region superiorly to the piriformis muscle
What is the major gonadal artery of the female pelvis?
The ovarian artery
What is the major gonadal artery of the male pelvis?
Testicular artery
Where do the gonadal arteries arise from?
From the abdominal aorta, distal to the origin of the renal arteries.
Describe the course of the ovarian artery
The artery descends towards the pelvis, crossing the pelvic brim and the origin of the external iliac vessels. It moves medially, dividing into an ovarian branch and tubal branches, which supply their respective structures.
How does the course of the testicular artery differ?
The testicular artery reaches the scrotum via the inguinal canal, and therefore does not actually enter the pelvis.
What is the superior rectal artery a continuation of?
The terminal continuation of the IMA
Describe the course of the superior rectal artery
It crosses the left common iliac artery and descends in the mesentery of the sigmoid colon. It gives rise to branches that supply the rectum.
What is a hysterectomy?
The surgical removal of the uterus, usually as a result of cervical or uterine cancer.
Why must care be taken during hysterectomy?
Care must be taken not to damage the ureters during clamping of the uterine arteries during a hysterectomy.
The relationship between the two can be remembered using the phrase ‘water under the bridge’. Water refers to the ureter (urine), and the uterine artery is the bridge.
