41 Vasculature

STUDYAIMS

At the end of your study, you should be able to:

Describe the arterial blood supplyof the pelvis and perineum

Name the visceral and parietal branches of the internal iliac artery

Outline the venous drainage of the pelvis and perineum

Outline the lymphatic drainage of the pelvis and perineum

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GUIDE

Pelvis and Perineum: Vasculature

Pelvic Vasculature

[Plate 383, Arteries and Veins of Pelvis: Male]

Arterial supply to the pelvis

Four arteries supplythe true or lesser pelvis and its contents

Paired internal iliac arteries

Paired ovarian arteries

Medial sacral artery

Superior rectal artery

Main arterial supplyis from branches internal iliac artery

Medial sacral arteryfrom abdominal aorta supplies lower lumbar vertebrae, sacrum, and coccyx Superior rectal artery(branch inferior mesenteric artery) supplies upper region of rectum

Ovarian arteries (from abdominal aorta) supplythe ovaries, descending in the suspensoryligament of the ovary Internal iliac artery

One of two terminal branch common iliac arteries (other is external iliac)

Common iliac bifurcates anterior to sacroiliac joint

Internal iliac arteryis crossed byureter at its origin

Passes posteromediallyinto the true pelvis beneath the peritoneum, giving off branches to the buttocks, thigh, perineum, and pelvic viscera. Usuallyends at the level of the superior edge of the greater sciatic foramen bydividing into anterior and posterior divisions

Branches of Internal Iliac Artery and Structures Supplied

	Visceral VesselsStructures Supplied		Comment
	Umbilical artery	Superior urinarybladder via	From anterior division of internal iliac
		superior vesical	Obliterates and becomes median umbilical ligament
		Arteryto ductus deferens in males
	Superior vesical	Superior urinarybladder	From proximal part of umbilical
	artery	Ureter in pelvis	Branch given to ductus deferens

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Inferior vesical	Inferior urinarybladder	From anterior division of internal iliac
artery	Prostate	Onlyexists in males
	Seminal vesicles
	Ductus deferens
Uterine artery	Vagina	From anterior division of internal iliac
	Uterus	Terminates byanastomosing with ovarian artery
	Uterine tubes
Middle rectal	Inferior rectum	From anterior division of internal iliac
artery	Seminal vesicles
	+/- prostate
Vaginal artery	Vagina	From uterine
	Cervix
	Inferior urinarybladder
Parietal	Structures Supplied	Comment
Branches
Obturator artery	Pelvic muscles	From anterior division of internal iliac
	Head of femur	Runs through obturator canal with obturator vein and artery
	Muscles of medial compartment	Occasionallycan take origin from inferior epigastric artery
	thigh
Superior gluteal	Piriformis muscle	From posterior division of internal iliac
artery	All three gluteal muscles	Exits via greater sciatic foramen above piriformis muscle
	Tensor fascia lata
Inferior gluteal	Pelvic diaphragm	From anterior division of internal iliac
artery	Piriformis	Exits via greater sciatic foramen below piriformis muscle
	Quadratus femoris
	Gluteus maximus
	Hamstring muscles
Internal	Muscles and skin of anal and	From anterior division of internal iliac
Pudendal Artery	urogenital triangles	Passes through greater sciatic foramen below piriformis and enters
	Erectile bodies	perineum via lesser sciatic foramen
Iliolumbar artery	Psoas major	From posterior division of internal iliac
	Iliacus	Ascends deep to common iliac and anastomoses with lower lumbar
	Quadratus lumborum	arteries
Lateral sacral	Piriformis	From posterior division of internal iliac
artery	Contents of sacral canal	Runs on piriformis
	Erector spinae	Sends branches into pelvic sacral foramina

Venous drainage of the pelvis

Veins accompanymain branches of internal iliac artery

Around pelvic organs theyanastomose to form venous plexuses: rectal, vesical, prostatic, uterine and vaginal

Extensive prostatic venous plexus and anastomoses occur around the pelvic viscera in a male

Extensive anastomoses and venous plexus surrounding the uterus and vagina in female

Venous plexuses communicate with each other

Veins and plexuses eventuallydrain into internal iliac vein

Some venous blood from the pelvis drains to the internal vertebral venous plexus

Internal iliac veins are found deep to the arteries

Become confluent with external iliac veins to form common iliac veins

Aportacaval anastomosis occurs between the superior rectal vein and inferior rectal veins

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Vasculature Supply of the Pelvic Organs

	Organ	Blood Supply	Venous Drainage
	Pelvic organs
	common to male
	and female
	Ureter	Renal, gonadal, common iliac, uterine/inferior vesical,	Parallel to the arteries
		and middle rectal arteries
	Urinarybladder	Superior and inferior vesical arteries of anterior	Internal iliac vein via vesical and prostatic venous
		division of internal iliac artery	plexuses
	Male pelvic
	structures
	Seminal glands	Branches of inferior vesical and middle rectal arteries	Drain to internal iliac veins
	Ductus deferens	Inferior epigastric artery, inferior vesical, and middle	Drain to internal iliac veins
		rectal arteries
	Prostate gland	Inferior vesical and middle rectal arteries	Prostatic venous plexus receives the deep dorsal vein
			of penis and vesical veins. It drains into the internal
			iliac veins
	Female pelvic
	structures
	Ovary	Ovarian arteryfrom abdominal aorta, which	Ovarian vein drains to inferior vena cava on the right
		anastomoses with the uterine artery(a branch of the	and left renal vein on the left

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	internal iliac artery)
Uterine tube	Ovarian arteryfrom abdominal aorta, which	Ovarian vein drains to inferior vena cava on the right
	anastomoses with the uterine artery(a branch of the	and left renal vein on the left
	internal iliac artery)
Uterus	Branches of ovarian artery(from the aorta), uterine	Ovarian vein (see ovary), uterine and vaginal veins
	and vaginal arteries (from the internal iliac artery)	(drain to the internal iliac veins)

Lymphatic drainage of the pelvis

Lymphatic vessels accompanyarteries

Most lymph drains to internal iliac nodes and then to common iliac nodes The ovaries, testes, and rectum drain to aortic nodes

Some vessels from bodyof the uterus drain to superficial inguinal nodes, following the round ligament of the uterus

Perineal Vasculature

Arterial supply of the perineum

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Mainlyfrom internal pudendal artery(branch internal iliac artery)

Supplies muscles and skin of anal and urogenital triangles, erectile bodies of perineum

Internal pudendal artery

Passes through greater sciatic foramen inferior to the piriformis muscle

Loops around the sacrospinous ligament

Enter the lesser sciatic foramen to reach the ischioanal (ischiorectal) fossa and perineum

Traverses the fossa in the pudendal (Alcock's) canal

Gives off branches before entering the canal and in pudendal canal

Medial to ischial tuberosity, terminates as deep and dorsal arteries of penis (or clitoris)

Branches of Internal Pudendal Artery Supplying Perineum

Branch	Structure Supplied	Comment
Inferior rectal artery	Anal canal
Posterior scrotal (labial) artery	Scrotum (labia in females)
Branch to bulb of penis	Bulb of penis (vestibule in females)
Branch to crus of penis	Crus of penis (clitoris in females)
Dorsal arteryof penis (clitoris)	Erectile tissue corpus cavernosum	Smaller arteryin females
Deep arteryof the penis (clitoris)	Erectile tissue corpus cavernosus	Smaller arteryin females

Venous drainage of the perineum

Branches of internal pudendal arteryaccompanied byvenae comitantes

Drain into internal iliac vein

Lymphatic drainage of the perineum

Penis and vulva drain to the superficial inguinal nodes

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