Atlas of Human Anatomy by Netter

Relations of the Urinary Bladder

Border Structure

Superior Peritoneum

Ileum

Sigmoid colon

Inferolateral Obturator internus muscle

Levator ani muscle

Obturator nerve

Obturator artery and vein

Superior vesical artery and vein

Anterior Retropubic space-containing adipose tissue and veins

Pubic crest

Posterior-male Seminal vesicles

Ampulla of ductus deferens

Rectovesical pouch

Ampulla of rectum

Posterosuperior-female Vesicouterine pouch

Body of uterus

Posterior-female Cervix

Anterior wall vagina

Inferior-male Prostate

Prostatic venous plexus

Arterial supply

Superior vesicle arteries (branches of internal iliac artery) supply apex and superior part of bladder

Inferior vesical arteries supply fundus and neck in males

Vaginal arteries (branches of uterine arteries) supply fundus and neck in females

Obturator arteries (branches of internal iliac artery) provide arterial twigs

Venous drainage

Vesical venous plexus drains to internal iliac plexus via inferior vesical veins

Communicates with prostatic venous plexus in males and uterovaginal venous plexus in females

Female urethra

Three- to 4-cm long fibromuscular tube, bound to anterior vaginal wall

Extends from internal urethral meatus of bladder to external meatus situated just anterior to the vaginal opening in the vestibule

Descends with vagina through urogenital hiatus and pelvic diaphragm and through perineal membrane where it is surrounded by external

sphincter urethrae

Paraurethral glands, homologs to the prostate, open on either side near external urethral orifice

Supplied by internal pudendal and vaginal arteries

Drained by veins of same name

Innervated by branches of pudendal nerve via S2-S4 spinal cord segments and afferents run with pelvic splanch

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Male urethra

Twenty-cm fibromuscular tube

Conveys both urine and semen

Extends from internal urethral meatus of bladder to external urethral meatus in glans penis

Divided into three parts: prostatic; membranous and spongy urethra

Comparison of Prostatic, Membranous and Spongy Parts of the Male Urethra

Prostatic Urethra Membranous Urethra Spongy Urethra

Length 3 cm 2 cm 15 cm

Extent Internal urethral meatus to apex of prostate Apex of prostate to perineal

membrane

Bulb of penis to glans

penis

Key

Anatomical

Features

Urethral crest (midline ridge)

Prostatic sinuses (site of opening prostatic ducts)

Prostatic utricle (blind-ending sac on urethral crest;

remnant of fetal duct forming uterus in females)

Ejaculatory duct (opens either side of the utricle)

Surrounded by striated muscle of

external urethral sphincter

Bulbourethral glands lie

posterolaterally

Pubic symphysis lies anteriorly

attaching via pubourethral

ligaments

Blood

Supply

Inferior vesical and rectal arteries Inferior vesical and rectal arteries Internal pudendal artery via

dorsal arteries of penis

Venous

Drainage

Veins of same names and prostatic venous plexus Veins of same names and prostatic

venous plexus

Prostatic venous plexus

and internal pudendal

veins

Nerve Pudendal nerve (S2-S4) and prostatic plexus Pudendal nerve (S2-S4) and Pudendal nerve (S2-S4)