Vessels and Nerves of Pelvis - Anatomy Flashcards
Where does abdominal aorta sit?
Just to left of midline
Where do the common iliac arteries branch into external and internal iliac arteries?
Roughly at level of pelvic brim
Where does the external iliac artery pass?
Underneath inguinal ligament
What branch does the external iliac artery give off just before passing under the inguinal ligament?
Inferior epigastric artery
Where does the inferior epigastric artery course?
Ascends towards anterior abdominal wall and pierces transveralis fascia
What is the interior epigastric artery covered by?
Layer of peritoneum –> forming the lateral umbilical fold/ligament
What does the interior epigastric artery anastamose with?
The superior epigastric artery
What is the superior epigastric artery?
One of the two terminal branches of the internal thoracic artery
What does the internal iliac artery supply?
Viscera of pelvis
Where do the iliac veins drain into?
Drain the lower limb and pelvis into the IVC
What does the IVC give rise to?
Right and left common iliac vein (and then internal and external iliac vein)
Where does the vas deferens pass? What does it transport?
Passes from testes, through inguinal canal, on superior surface of bladder
Transports sperm to the prostatic urethra
What muscle is found just superior to the iliac crest?
Quadratus lumborum
What nerve passes on top of the psoas major? What is this nerve a branch of?
Genitofemoral nerve –> branch of the lumbar plexus
Where does the right gonadal vein drain into?
Directly into IVC
Where does the left gonadal vein drain into?
Into the left renal vein
What is the sacral promontory?
Inwardly projecting anterior part of the body of the first sacral vertebra
Forms the posteriorly margin of the pelvic inlet
Once the inferior epigastric artery passes under the inguinal ligament, what does it become?
Changes name to femoral artery
What is the 1st branch of the internal iliac artery?
Umbilical artery
Where does the umbilical artery course towards? What happens to it?
Courses towards the anterior abdominal wall but becomes obliterated towards distal end
What does the umbilical artery give rise to?
Numerous superior vesical arteries
What do the superior vesical arteries supply?
Superior part of bladder and pelvic part of ureter
What is the 2nd branch of the internal iliac artery?
Obturator artery
Describe the course of the obturator artery
Courses towards obturator foramen where it passes through defect (canal) in muscle and fascia with the obturator nerve
What does the obturator artery supply?
Medial aspect of thigh
What is the 3rd branch of the internal iliac artery?
Uterine artery (in females)
Inferior vesical artery (in males)
Describe the course of the uterine artery (mention the ureter)
Passes over top of ureter (water travels under the bridge)
Supplies uterus
What branch does the uterine artery give off?
Vaginal branch
What does the inferior vesical artery supply?
The prostate gland and the seminal vesicles
What are the branches of the internal iliac artery?
- Umbilical artery
- Obturator artery
- Uterine artery/superior vesical artery
- Vaginal artery
- Internal pudendal artery
- Middle rectal artery
- Inferior gluteal artery
- (Superior gluteal artery)
Describe the course of the internal pudendal artery
Leaves pelvic cavity just behind the sacrospinous ligament and leaves via the greater sciatic foramen
Enters perineum via the lesser sciatic foreamen
What does the internal pudendal artery supply?
Structures of the perineum
Just before it leaves the pelvic cavity, what branch does the internal pudendal artery give off?
Middle rectal artery
What is the most posterior branch of the internal iliac artery?
Inferior gluteal artery
What does the inferior gluteal artery supply?
Some of muscles within the gluteal region
Where does the inferior gluteal artery leave the pelvic cavity?
Greater sciatic foramen
Why is the piriformis muscle an important landmark?
Both the internal pudendal artery and the inferior gluteal artery leave the pelvic cavity just inferior to the piriformis muscle
The superior gluteal artery is found superiorly to the piriformis
What vessel leaves the pelvis just superior to the piriformis?
Superior gluteal artery
How does the superior gluteal artery leave the pelvis?
Via the greater sciatic foramen
What is the sacral foramina?
On the transverse processes of the lower sacral vertebrae, on each side, are a series of four openings (sacral foramina); the sacral nerves and blood vessels pass through these openings.
What do the nerves emerging from the sacral foramina merge to form?
Sacral plexus
What is the sciatic nerve?
One of major nerves of sacral plexus: supplies posterior compartment of leg
What covers the obturator foramen?
It is covered by thin fibrous membrane, the obturator membrane, which is covered on the internal and external surfaces by the muscles obturator internus and obturator externus respectively.
What does the obturator internus go on to attach to?
Femur
What is found in the covering of the obturator foramen?
Defect (forms obturator canal)
Where is the piriformis muscle found?
Just posterior to the nerve roots from the sacral foramina
What is the piriformis?
Is a pyramid shape muscle that attaches from the sacrum and passes through the greater sciatic foramen to attach to the femur
Where does the piriformis muscle pass through?
The greater sciatic foramen
Where does the coccygeus muscle originate from? Where does it pass?
It originates from the ischial spines and travels to the lateral aspect of the sacrum and coccyx, along the sacrospinous ligament.
What does the pelvic diaphragm/floor separate?
Pelvic cavity (superiorly) from the perineum (inferiorly)
What is the obturator fascia?
Fascia that covers the pelvic surface of the obturator internus muscle
What is a particular thickening of the obturator fascia called?
Tendinous arch
What does the tendinous arch act as?
An attachment point for the pelvic diaphragm and the pelvic floor muscles
Where does the piriformis muscle attach to? Describe its course
Passes through the greater sciatic foramen to attach to the femur
Where does the sacrospinous ligament run from/to?
From the sacrum to the ischial spine
Where does the sacrotuberous ligament run from/to?
From the sacrum to the ischial tuberosity
What is the pelvic floor made up of?
Levator ani muscles and coccygeus muscle
What is found deep to the obturator fascia?
Obturator internus muscle covering the obturator foramen
What is the levator ani?
Used to describe 3 muscles of the pelvic floor
- Puborectalis
- Pubococcygeus
- Iliococcygeus
Describe the puborectalis muscle
Most medial muscle runs from pubic part of tendinous arch and loops around the rectum like a sling (fibres from left and right converge)
Some fibres converge just anterior to the rectum as well
What does the puborectalis muscle form?
The anorectal junction/angle
What is job of levator ani and coccygeus?
- Acts to keep all of pelvic viscera within pelvis and also contribute to continence
- Help with formation of external sphincters
Describe the pubococcygeus muscle
Attaching from pubic region of tendinous arch to the coccyx
Fibres from either side converge and join onto the coccyx
Describe the iliococcygeus muscle
Runs from ilio part of tendinous arch to the coccyx
Fibres from either side converge and attach to coccyx
