Vascular and Nerve Supply of the Pelvis Flashcards
The abdominal aorta bifurcates at which vertebral location?
L4
What does the abdominal aorta bifurcate into?
Left and right common iliac arteries
Each common iliac artery bifurcates into which arteries?
External and internal iliac arteries
Where does the common iliac artery bifurcate?
Anterior to the sacroiliac joint
What are the two branches of the external iliac artery?
Deep circumflex iliac and inferior epigastric artery
The external iliac artery continues as what structure below the inguinal ligament?
Femoral artery
Which artery is specifically the major source of blood to structures within the pelvis?
Internal iliac artery
What crosses the external iliac artery at the pelvic brim?
Ureter
What are the branches of the internal iliac artery of the posterior trunk?
Iliolumbar, lateral sacral and superior gluteal arteries
What are the branches of the iliolumbar artery?
Iliac branch and lumbar branch
What branch of the iliolumbar artery supplies the iliacus muscle and ilium?
Iliac branch
Which branch of the iliolumbar artery supplies psoas major and quadratus lumborum muscles?
Lumbar branch
Which branch of the internal iliac artery anastomoses with the median sacral artery?
Lateral sacral artery
Which branch of the internal iliac artery exits the pelvis through the greater sciatic foramen superior to the piriformis muscle?
Superior gluteal artery
The superior gluteal artery usually passes through what structures?
Lumbosacral trunk and 1st sacral nerve
Which branch of the internal iliac artery is a part of the anterior trunk and exits the pelvis through the greater sciatic foramen inferior to the piriformis?
Inferior gluteal artery
Which branch of the internal iliac artery is a part of the anterior trunk and passes between the 1st and 2nd or 2nd and 3rd sacral nerves?
Inferior gluteal artery
Which branch of the internal iliac artery is a part of the anterior trunk and exits the pelvis through the greater sciatic foramen between the piriformis and coccygeus muscles?
Internal pudendal artery
Which branch of the internal iliac artery is a part of the anterior trunk and enters the perineum through the lesser sciatic foramen giving off important branches?
Internal pudendal artery
Which branch of the internal iliac artery is a part of the anterior trunk and gives off the superior vesical arteries?
Umbilical artery
What part of the umbilical artery gives off the superior vesical arteries?
Proximal (patent) portion
What do the superior vesical arteries supply?
Superior part of the bladder
What gives rise to the artery of the ductus deferens?
One of the superior vesical arteries
The distal portion of the umbilical artery is obliterated and gives rise to what structure?
Medial umbilical ligament
Which branch of the internal iliac artery is a part of the anterior trunk and exits the pelvis through the obturator foramen?
Obturator artery
What does the obturator artery supply?
Muscles of the thigh
Which branch of the internal iliac artery is a part of the anterior trunk and supplies the inferior part of the bladder (in both sexes) and the prostate gland and seminal vesicles (in males)?
Inferior vesical artery
Which branch of the internal iliac artery is a part of the anterior trunk and supplies the middle portion of the rectum as well as the prostate and vagina?
Middle rectal artery
Which branch of the internal iliac artery is a part of the anterior trunk and is homologous to the artery of the ductus deferens in males?
Uterine artery
The uterine artery can sometimes form a common trunk with which arteries?
Vaginal or middle rectal arteries
Which branch of the internal iliac artery is a part of the anterior trunk and arises from a common trunk with the uterine or directly off the internal iliac artery?
Vaginal artery
What is the major supplier of blood to the pelvis?
Internal iliac artery
From where does the gonadal (testicular or ovarian) artery arise?
Abdominal aorta
From where does the superior rectal artery arise?
Inferior mesenteric artery
From where does the median sacral artery arise?
Behind the bifurcation of the abdominal aorta
Which two veins make up the common iliac vein?
Internal and external iliac veins
What veins unite to form the inferior vena cava?
Right and left common iliac veins
In general, tributaries of the internal iliac vein correspond to branches of which artery?
Internal iliac artery
Which pelvic structures have SOME portal drainage?
Rectum and anal canal
Most pelvic structures have their drainage into which venous system?
Caval system
What makes up the sacral plexus?
Lumbosacral trunk and the anterior primary rami of S1-S4
What cord levels make up the lumbosacral trunk?
L4, L5
What part of L4 makes up the lumbo sacral trunk?
Lower half
What part of S4 makes up the sacral plexus?
Upper half
The sacral plexus lies primarily on the anterior surface of which muscle?
Piriformis
The anterior primary rami of S1-S4 enter the pelvis through what structures?
Anterior sacral foramina
What are the branches of the sacral plexus that supply the buttock and lower limb?
Superior and inferior gluteal nerves, sciatic nerve, nerve to obturator internus muscle, nerve to quadratus femoris muscle, and posterior cutaneous nerve of thigh
What are the cord levels of the superior gluteal nerve?
L4-S1
What branch of the sacral plexus is the only nerve to exit SUPERIOR to the piriformis?
Superior gluteal nerve
What does the superior gluteal nerve supply?
Gluteus medius, gluteus minimus, and tensor fasciae latae muscles
What are the functions of the anterior gluteal muscles (medius, minimus, and tensor fasciae latae)?
Abductors, prevent pelvis from slumping to unsupported side during gait
What is the term for the type of gait that occurs when the anterior gluteal muscles are dysfunctional?
Trendelenburg’s Gait
What are the cord levels for the inferior gluteal nerve?
L5-S2
What does the inferior gluteal nerve supply?
Gluteus maximus
What are the cord levels of the sciatic nerve?
L4-S3
What is the largest nerve in the body?
Sciatic nerve
What is the condition where the sciatic nerve is compromised?
Sciatica
What are the cord levels of the nerve to obturator internus muscle?
L5-S2
What does the nerve to obturator internus supply?
Obturator internus and superior gemellus muscles
What are the functions of the gluteus maximus muscle?
Trunk control and standing form a seated position
What are the cord levels for nerve to quadratus femoris muscle?
L5-S1
What does the nerve to quadratus femoris supply?
Quadratus femoris and inferior gemellus muscles
What are the cord levels for the posterior cutaneous nerve of thigh?
S1-S3
What does the posterior cutaneous nerve of the thigh supply?
Sensory to part of the gluteal region and perineum
What are the branches of the sacral plexus that supply the pelvis?
Nerve to piriformis muscle, nerves to levator ani and coccygeus muscles, nerve to external anal sphincter muscle, and pudendal nerve
What are the cord levels for the nerve to piriformis muscle?
S1, S2
Impingement of the nerve to piriformis muscle can lead to what condition?
Sciatica (“Piriformis Syndrome”)
What are the cord levels for nerves to levator ani and coccygeus muscles?
S3, S4
What issues can arise from damage to the nerves to levator ani and coccygeus muscles?
Urinary and fecal continence and parturition issues
What are the cord levels for nerve to external anal sphincter muscle?
S4
What are the cord levels of the pudendal nerve?
S2-S4
The pudendal nerve gives off important branches to what structure?
Perineum
Impingement of the pudendal nerve can lead to what issue?
Erectile dysfunction
What forms the coccygeal plexus?
Ventral primary rami of S4, S5 and the coccygeal nerve
What does the coccygeal plexus supply?
Sacrococcygeal joint, the coccyx, and the overlying skin
What are the two ways in which sympathetic fibers reach the pelvis?
Downward continuation of both the sympathetic trunk and the aortic plexus (as the superior hypogastric plexus)
What forms as the left and right sympathetic trunks join together in front of the coccyx?
Ganglion impar
What mostly makes up the superior hypogastric plexus?
Sympathetic fibers from the lumbar splanchnic nerve and visceral afferent fibers
What long, narrow nerve plexuses connect the superior hypogastric plexus to the inferior hypogastric plexus?
Left and right hypogastric nerves
What plexuses are formed by the union of the hypogastric, pelvic splanchnic, and sacral splanchnic nerves?
Left and right inferior hypogastric plexuses
What makes up the left and right inferior hypogastric plexuses?
Sympathetic fibers, parasympathetic fibers, and visceral afferent fibers
The inferior hypogastric plexuses give rise to what structures that supply pelvic viscera?
Subsidiary plexuses
What are the preganglionic sympathetic nerves which arise from the sympathetic trunk and synapse in the inferior hypogastric plexus?
Sacral splanchnic nerves
What are the parasympathetic nerves which arise from the sacral segments of the spinal cord (S2-S4) and contribute to form the inferior hypogastric plexuses and supply pelvic viscera?
Pelvic splanchnic nerves
