URETERSURETERS

URINARY BLADDERURINARY BLADDER

URETHRAURETHRA

OBJECTIVESOBJECTIVES

At the end of the lecture, students should be able At the end of the lecture, students should be able to:to:

Describe the course of ureter & identify the sites of Describe the course of ureter & identify the sites of ureteric constrictionureteric constriction

Describe the important relations & identify certain Describe the important relations & identify certain areas (trigone, uvula vesicae) in the base of areas (trigone, uvula vesicae) in the base of urinary bladder.urinary bladder.

List the blood supply, lymphatic drainage & nerve List the blood supply, lymphatic drainage & nerve supply of urinary bladdersupply of urinary bladder

Differentiate between male & female urethra Differentiate between male & female urethra regarding length, structure, course & function.regarding length, structure, course & function.

UreterUreter A 25 – 30 cm long A 25 – 30 cm long

muscular tube transporting muscular tube transporting urine from kidney to urinary urine from kidney to urinary bladder.bladder.

Begins as a continuation of Begins as a continuation of renal pelvis.renal pelvis.

COURSE IN ABDOMEN: COURSE IN ABDOMEN: It descends anterior to psoas major muscle (opposite the It descends anterior to psoas major muscle (opposite the

tips of lumbar transverse processes).tips of lumbar transverse processes). It crosses the end (bifurcation) of common iliac artery to It crosses the end (bifurcation) of common iliac artery to

enter the pelvis.enter the pelvis.

COURSE IN PELVIS & COURSE IN PELVIS & TERMINATION: TERMINATION:

Runs downward in front to internal Runs downward in front to internal iliac artery, reaches ischial spineiliac artery, reaches ischial spine

Turns forward and medially , Turns forward and medially , enters the upper lateral angle of enters the upper lateral angle of urinary bladderurinary bladder

Near its termination, is crossed by Near its termination, is crossed by the vas deferensthe vas deferens

Passes obliquely through the wall Passes obliquely through the wall of bladder for about ¾ inch before of bladder for about ¾ inch before opening into the bladder cavity. opening into the bladder cavity.

Bladder muscle contraction Bladder muscle contraction mechanically closes off ureteral mechanically closes off ureteral

orifice which prevents a reverse flow orifice which prevents a reverse flow of urine toward the kidneyof urine toward the kidney

Ureteric ConstrictionsUreteric Constrictions

The ureter has The ureter has constrictions at constrictions at three points (sites of three points (sites of obstruction and obstruction and stone impaction)stone impaction)

1.1. At the ureteropelvic At the ureteropelvic junctionjunction

2.2. At the crossing of At the crossing of external/common external/common iliac arteryiliac artery

3.3. At site of entrance At site of entrance to bladderto bladder

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Arterial SupplyArterial Supply

Ureter is supplied by Ureter is supplied by multiple arteries multiple arteries throughout its coursethroughout its course

From above downward, From above downward, these are::these are::

1.1. Renal arteryRenal artery

2.2. Gonadal arteryGonadal artery

3.3. Common iliac arteryCommon iliac artery

4.4. Internal iliac arteryInternal iliac artery

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Urinary BladderUrinary Bladder

Located immediately Located immediately behind behind the pubic symphysisthe pubic symphysis

Shape and relations vary Shape and relations vary according to the amount of according to the amount of urine it containsurine it contains

An empty bladder:An empty bladder: In adults, is In adults, is entirely a entirely a

pelvic organpelvic organ; as it fills, ; as it fills, rises up into the rises up into the hypogastric region.hypogastric region.

In young children, it In young children, it projects above the pelvic projects above the pelvic inletinlet

An empty bladder is An empty bladder is pyramidal in shape pyramidal in shape having:having: AnAn apexapex AA base (posterior base (posterior

surface)surface) AA superiorsuperior surfacesurface TwoTwo infrolateral infrolateral

surfacessurfaces AA neckneck

ApexApex Directed forwardDirected forward Lies behind the upper Lies behind the upper

margin of the margin of the symphysis pubissymphysis pubis

Is connected to Is connected to umbilicus by the umbilicus by the median umbilical median umbilical ligament ligament (remnant of (remnant of urachus)urachus)

Base or Posterior Base or Posterior surface surface

Triangular in shapeTriangular in shape Upper part covered by Upper part covered by

peritoneumperitoneum Lower part related to:Lower part related to:

In malesIn males: vas : vas deferentia and deferentia and seminal vesiclesseminal vesicles

In femalesIn females: vagina: vagina

Superior surfaceSuperior surface Completely covered by peritoneum.Completely covered by peritoneum. Related to the coils of ileum or sigmoid colon in males Related to the coils of ileum or sigmoid colon in males

and to uterus in femalesand to uterus in females

Male pelvis Female pelvis

Infrolateral surfaces:Infrolateral surfaces: Related in front to the Related in front to the

retropubic pad of fat & retropubic pad of fat & the pubic bonesthe pubic bones

Posteriorly lie in contact Posteriorly lie in contact with the obturator with the obturator internus above and internus above and levator ani belowlevator ani below

Retropubic fatRetropubic fat Accomodates distention of bladderAccomodates distention of bladder Continuous with anterior abdominal wall. Continuous with anterior abdominal wall. Rupture of bladder results in escape of urine to Rupture of bladder results in escape of urine to

anterior abdominal wallanterior abdominal wall

Neck:Neck: Lies inferiorly, and is the Lies inferiorly, and is the

most fixed part of the most fixed part of the bladderbladder

Is related to lower border Is related to lower border of symphysis pubisof symphysis pubis

In male, rests on the In male, rests on the upper surface of upper surface of prostate. Here, the prostate. Here, the smooth muscle fibers of smooth muscle fibers of the bladder are the bladder are continuous with those of continuous with those of the prostatethe prostate

The circular muscle The circular muscle fibers thickened to form fibers thickened to form the sphincter vesicae the sphincter vesicae

Interior of the Urinary BladderInterior of the Urinary Bladder Mucous membrane thrown

into folds except in the triangular region in the base of bladder, between between the openings of the two the openings of the two ureters and the urethra. ureters and the urethra. This region is called the This region is called the ‘trigone’‘trigone’.. Here The mucous membrane is always smooth even when the bladder is empty

Uvula vesicaeUvula vesicae, a small elevation located just behind the urethral orifice, It is produced by the median lobe of prostate.

Arterial supply: Arterial supply: from internal iliac arteryfrom internal iliac artery Venous drainage: Venous drainage: into internal iliac veininto internal iliac vein Lymphatics:Lymphatics: into internal iliac lymph nodesinto internal iliac lymph nodes

The nerves form the vesical nerve The nerves form the vesical nerve plexus that contains:plexus that contains: Sympathetic fibers Sympathetic fibers derived mainly derived mainly

fromfrom L1,2L1,2 Parasympathetic fibers Parasympathetic fibers derived from derived from

pelvic splanchnic nerves S2,3,4pelvic splanchnic nerves S2,3,4 Sensory fibers Sensory fibers from the bladder are from the bladder are

visceral and transmit pain sensation visceral and transmit pain sensation resulting from overdistentionresulting from overdistention

Blood & Nerve SupplyBlood & Nerve Supply

The normal capacity The normal capacity of bladder is about of bladder is about 300-500ml.300-500ml.

As bladder fills, the As bladder fills, the superior surface superior surface bulges upward into bulges upward into abdominal cavity.abdominal cavity.

The peritoneal lining The peritoneal lining is peeled off the is peeled off the lower part of lower part of anterior abdominal anterior abdominal wall and thewall and the bladder bladder comes into direct comes into direct contact with the contact with the anterior abdominal anterior abdominal wallwall

Male UrethraMale Urethra About 8 inches (20cm) About 8 inches (20cm)

longlong Extends from the neck Extends from the neck

of bladder to the of bladder to the external urinary meatus external urinary meatus on the tip of the glans on the tip of the glans penispenis

Divided into three Divided into three parts:parts: ProstaticProstatic MembranousMembranous PenilePenile

Prostatic urethra Prostatic urethra Length=3 cmLength=3 cm Widest & most dilatableWidest & most dilatable Extends from neck of Extends from neck of

bladder inside prostate bladder inside prostate glandgland

Structures openings into Structures openings into prostatic urethra:prostatic urethra:

Ejaculatory ductsEjaculatory ducts Ducts of prostate glandDucts of prostate gland

Membranous urethraMembranous urethra Length=1 cmLength=1 cm Surrounded by external Surrounded by external

urethral sphincterurethral sphincter

Penile (spongy) urethraPenile (spongy) urethra Length=16 cmLength=16 cm narrowest part of whole urethranarrowest part of whole urethra Extends inside penis & opens Extends inside penis & opens

externally through external externally through external urethral orificeurethral orifice

Female UrethraFemale Urethra

Extends from neck Extends from neck of urinary bladder of urinary bladder to open externally to open externally through the through the external urethral external urethral orifice (anterior to orifice (anterior to the vaginal the vaginal opening)opening)

Has only urinary Has only urinary functionfunction

FLY HIGH