Urinary bladder Urinary bladder and and UrethraUrethra

Prof. Dr. Selda Önderoğlu

Anatomy Department

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• Muscular sac (vesicle) for urine storage.• Normal Volume=220ml.

- however can tolerate 500ml. 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

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shape, surfaces

• Shape: triangular pyramid• Has: base (fundus)

neck

apex • Surfaces: 1 superior

2 inferolateral

Only superior surface is covered by peritoneum.

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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.

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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 (supravaginal part of cervix)

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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

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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

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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

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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)

• Backwards: posterior lig.18

False ligaments

• Folds of peritoneum

• Median umbilical fold

• Medial umbilical folds (2)

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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

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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 membrane26

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.(S2-4)

• Lymph: external iliac-common iliac

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Male urethra

• 15-20cm.long

• Extends From internal urethral orifice(urin. Bladd.) to external urethral orifice at the tip of penis

• 3 Parts: prostatic

membranous

spongiose

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Prostatic part• Widest part of male urethra.

• 3cm.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

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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.

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Spongiose part• 15cm.long• Located in the corpus spongiosum

penis.• Narrow (about 6mm.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• 4-5cm. Long, 6mm.wide,much dilatable.

• From internal urethral orifice(bladder) to

external urethral ofifice(anteroposterior slit which is 2,5cm.anterio to the opening of vagina)

• 2 parts:pelvic&perineal

• Epithelium contains longitudinal folds+urethral crest

• urethral glands(homologous to prostate)+ minute recesses(lacunae)+paraurethral duct.

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Sphincters of urethra1-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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