Urinary bladder and Urethra Prof Dr Selda nderolu

Urinary bladder and Urethra Prof. Dr. Selda Önderoğlu Anatomy Department

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• Muscular sac (vesicle) for urine storage. • Normal Volume=220 ml. - however can tolerate 500 ml. of urine. • Location in Adult; when empty: entirely within lesser pelvis; when distended: expands into abdominal cavity • Location in child: even when empty in lesser pelvis +abdominal cavity 3

shape, surfaces • Shape: triangular pyramid • Has: base (fundus) neck apex • Surfaces: 1 superior 2 inferolateral Only superior surface is covered by peritoneum. 4

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• When distended the bladder expands into the abdominal cavity, may arise as high as the umbilicus thus, can be approached surgically by incisions or punctures through the ant. Abd. wall without traversing the peritoneum. 6

Apex and Superior surface • Apex: anterior end, directed forwards and upwards to the umbilicus ( median umbilical lig. (urachus) and fold) • Superior surface: triangular, lat borders run from apex backwards to the entrance of of ureter into the bladder. covered by peritoenuem except in female very post. part is devoid of peritoneum 7 (supravaginal part of cervix)

Superior surface in male and female (peritoneal pouches) • Male: from post. border the peritoneum is reflected from bladder to rectum: rectovesical pouch; at the sides of this pouch located: paravesical fossae • Female: peritoneum is reflected form bladder to uterus: vesicouterine pouch 8

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Fundus (base) • Directed backwards and downwards. • Female: related to vagina • Male: related to rectum - upper part rectovesical pouch. - lower part: seminal vesicles+deferent ducts are located, the tissue bw. is called the rectovesical fascia. 11

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neck • Is the lowest region of bladder • Pierced by the internal orifice of urethra • In Male: rests on the base of prostate, • In Female: rests on pelvic fascia 15

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Inferolateral surfaces (2) • Face anteroinferiorly. • Related to posterior surface of pubis, filled with adipose tissue: retropubic pad. • Male: puboprostatic ligament • Female: pubovesical ligament 17

Ligaments of urinary bladder (true and false ligs. ) • except superior surface (peritoneum) other parts are connected to other structures by a fibroareolar tissue (true ligaments) • On each side: lateral true ligs. • Ant. ’ly: puboprostatic ligs. (pubovesical ligs. ) • Apex: median umbilical lig. (urachus) 18 • Backwards: posterior lig.

False ligaments • Folds of peritoneum • Median umbilical fold • Medial umbilical folds (2) 19

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Internal surface • Has Folds of mucous membrane except a small triangular area above and behind the internal orifice of urethra. • Apex: internal orifice of urethra. • Base: interureteric crest. • Both ends of base: R and L ureteric orifice 24

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structure • Peritoneum • Muscular layer: detrusor muscle 3 layers: external longitudinal middle circular (sphincter vesicae muscle , at the internal urethral orifice – involuntary-inn. By autonomic nerv. Syst. ) inner longitudinal • Mucous membrane 26

Vessels, nerves, lymphatics • Aa: superior&inferior vesical aa. (int. iliaca. ) Vv: vesical plexus-drain into internal iliac vv. • Nn: symp. (lower 2 thor. +upper 2 lumbar levels)+ parasymp. (S 2 -4) • Lymph: external iliac-common iliac 27

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Male urethra • 15 -20 cm. long • Extends From internal urethral orifice(urin. Bladd. ) to external urethral orifice at the tip of penis • 3 Parts: prostatic membranous spongiose 31

Prostatic part • Widest part of male urethra. • 3 cm. long • On the Posterior wall: -urethral crest, - prostatic sinus, orifices of prostatic ducts. -seminal colliculus, prostatic utricle( vagina masculina) -on each side opening of ejaculatory ducts 32

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Membranous part • Shortest and narrowest part. Least dilatable part. 2 cm. long • Passes through perineal membrane (urogenital diaphragm). • The membranous urethra is surrounded by the sphincter urethrae muscle (external urethral sphincter)- voluntary m. - inn. By Pudental n. 35

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Spongiose part • • 15 cm. long Located in the corpus spongiosum penis. Narrow (about 6 mm. in diameter) most dilated parts: intrabulbal fossa(at the commencement) + navicular fossa(at glans penis) • Narrowest place: external urethral orifice • Bulbourethral glands+ other urethral glands open here. 37

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Female urethra • 4 -5 cm. Long, 6 mm. wide, much dilatable. • From internal urethral orifice(bladder) to external urethral ofifice(anteroposterior slit which is 2, 5 cm. anterio to the opening of vagina) • 2 parts: pelvic&perineal • Epithelium contains longitudinal folds+urethral crest • urethral glands(homologous to prostate)+ minute 39 recesses(lacunae)+paraurethral duct.

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Sphincters of urethra 1 -ınternal sphicter – sphincter vesicae m. -at the beginning, int. urethral orifice. -involuntary –nonstriated m. fibers. -innervated by: pelvic splancnic nn 2 - external sphincter- sphincter urethrae muscle - at the urogenital diaphragm -voluntary-striated m. fibers. -innervated by: pudental n. 42

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