Urinary bladder and Urethra Dr. Sama-ul-Haque Dr. Safaa Ahmed

Objectives  Describe the normal site, size, shape & position of the urinary bladder.  Delineate its borders and surfaces.  Discuss its peritoneal covering and relations.  Discuss its blood and nerve supply.  Discuss its lymphatic drainage.  Describe the trigone area of the bladder & its clinical importance.

Objectives  Describe the normal site, shape and length of male and female urethra.  Discuss the relations of male and female urethra.  Discuss their blood and nerve supply  Discuss their lymphatic drainage  Describe the sphincters of male and female urethra.  Define Intravenous pyelography.  Define catheterization.

Urinary bladder  Lies behind the pubic bones with in pelvis.  Maximum capacity 500 ml.  Empty bladder is pyramidal in shape  Apex  Base (Posterior surface)  Superior surface  Two Inferolateral surfaces

It is freely movable except at the neck that is attached by puboprostatic ligament in male and pubovesical ligament in female The muscle of the bladder wall is called Detrusor muscle Trigone is triangular area where the two ureters and urethra open into its angles

Urinary bladder Apex:  Pointed anteriorly & lies behind the upper margin of the pubic Symphysis.  It is connected to the umbilicus by Median umbilical ligament (Remnant of urachus)

Urinary bladder Base (Posterior surface):  Superolateral angles are joined by ureters.  Inferior angle give rise to urethra.  Upper part of the posterior surface is covered by peritoneum.  Lower part of the posterior surface is related to seminal vesicles and vas deferens (males).  Posterior surface is related to uterus and vagina (females).

Urinary bladder Superior surface:  Covered with peritoneum.  Related to coils of ilium and sigmoid colon.

Urinary bladder Inferolateral surfaces:  Related to:  Retropubic pad of fat  Pubic bones  Levator ani muscle

Relations of urinary bladder (male) Anterior:  Pubic Symphysis  Anterior abdominal wall Posterior:  Rectovesical pouch  Vas deferens  Seminal vesicles  Rectovesical fascia  Rectum

Relations of urinary bladder (male) Lateral:  Obturator Internus muscle  Levator ani muscle Superior:  Peritoneal cavity  Coils of ilium  Sigmoid colon Inferior:  Prostate gland

Relations of urinary bladder & urethra in males

Urinary bladder and urethra in male

Relations of urinary bladder (female) Anterior:  Pubic Symphysis  Anterior abdominal wall Posterior:  Vagina

Relations of urinary bladder (female) Lateral:  Obturator Internus muscle  Levator ani muscle Superior:  Uterovesical pouch  Body of the uterus Inferior:  Urogenital diaphragm

Urinary bladder in females

Relations of urinary bladder & urethra in females

 Arterial supply:  Superior vesical artery & Inferior vesical artery (branches of internal iliac arteries)  Vaginal artery corresponds to the inferior vesical artery in the male.  Venous drainage:  In male, venous plexus around the bladder and prostate drain into inferior vesical vein  Also, superior vesical vein drains the bladder  Both veins drain into internal iliac vein

 In female, venous plexus around bladder drain into vaginal or uterovaginal vein and then to internal iliac vein  Also, superior vesical vein drains the bladder.  Lymphatic drainage:  The lymphatic vessels pass mainly to the internal iliac lymph nodes  Few vessels drain into the external iliac lymph nodes

Nerve supply

Urethra (male)  8 inches (20 cm) long  Extends from neck of the bladder to external meatus.  It has a tortous course  Three parts  Prostatic urethra (1.25 inches)  Membranous urethra (0.5 inches)  Penile or spongy urethra(6 inches)

Male Urethra  1. Prostatic part:  Widest portion  It is 3 cm long (1.25 inches)  Most dilatable part  Ducts of prostate gland & ejaculatory ducts open in it  2. Membranous part:  Lies within urogenital diaphragm  It is 1.5 cm long (0.5 inches)  It is the shortest and least dilatable part of the urethra.

Male Urethra cont.,  3. Penile part:  It is 15.5 cm (6 inches)  Is surrounded by erectile tissue of bulb and corpus spongiosum  Bulbourethral & penile glands open in it  It is dilated at the end as navicular fossa

Urethra (male)  External meatus is the narrowest part of the entire urethra.  Two sphincters:  Internal urethral sphincter (involuntary)  External urethral sphincter (voluntary)

Urethra (female)  1.5 inches (3.8 cm) long. It is easily dilatable It is straight  Extends from neck of the bladder to external meatus, where it opens into the vestibule, anterior to vagina.  Ducts of paraurethral glands opens on the sides of external meatus.  One sphincter:  External urethral sphincter  The female lacks a well-defined circular smooth muscle component comparable with the sphincter of the male. The muscle in this region is arranged longitudinally and extends into the urethral wall.

Blood Supply of Urethra Male Urethra Female Urethra Prostatic branches of inferior vesical and middle rectal arteries Dorsal artery of the penis Arteries of the bulb of the penis Internal pudendal artery Vaginal artery

Nerve Supply of Urethra Parasympathetic supply From pelvic plexus made of S2-4 roots to form pelvic splanchnic nerve Sympathetic supply T12-L1-2 Form hypogastric plexus and then form pelvic Somatic supply Pudendal nerve from sacral plexus Sensory and motor to external urethral sphincter

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