1. URETERS
URINARY BLADDER
URETHRA

2. OBJECTIVES At the end of the lecture, students should be able to:
Describe the course of ureter & identify the sites of ureteric constriction
Describe the important relations & identify certain areas (trigone, uvula vesicae) in the base of urinary bladder.
List the blood supply, lymphatic drainage & nerve supply of urinary bladder
Differentiate between male & female urethra regarding length, structure, course & function.

3. Ureter
A 25 – 30 cm long muscular tube transporting urine from kidney to urinary bladder.
Begins as a continuation of renal pelvis.
COURSE IN ABDOMEN:
It descends anterior to psoas major muscle (opposite the tips of lumbar transverse processes).
It crosses the end (bifurcation) of common iliac artery to enter the pelvis.

4. COURSE IN PELVIS & TERMINATION:
Runs downward in front to internal iliac artery, reaches ischial spine
Turns forward and medially , enters the upper lateral angle of urinary bladder
Near its termination, is crossed by the vas deferens
Passes obliquely through the wall of bladder for about ¾ inch before opening into the bladder cavity.
Bladder muscle contraction mechanically closes off ureteral orifice which prevents a reverse flow of urine toward the kidney

5. Ureteric Constrictions
The normal ureter is not of uniform caliber and shows constrictions at three points (possible sites of obstruction and stone impaction)
At the ureteropelvic junction
At the crossing of external/common iliac artery
At site of entrance to bladder (uretrovesical junction; narrowest part) 1 2 3

6. Arterial Supply
Ureter is supplied by multiple arteries throughout its course From above downward, these are::
Renal artery
Gonadal artery
Common iliac artery
Internal iliac artery 1 2 3 4

7. Urinary Bladder Located immediately behind the pubic symphysis
Shape and relations vary according to the amount of urine it contains
An empty bladder:
In adults, is entirely a pelvic organ; as it fills, rises up into hypogastric region of the abdomen.
In young children, it is an abdominal organ and projects above the pelvic inlet

8. An empty bladder is pyramidal in shape having:
An apex
A base (posterior surface)
Three surfaces:
A superior surface
Two infrolateral surfaces
A neck

9. Apex: Directed forward
Lies behind the upper margin of the symphysis pubis
Is connected to umbilicus by the median umbilical ligament (contains urachus, the remnant of allantoise)

10. Base (Posterior surface):
Triangular in shape
Upper part covered by peritoneum
Lower part related to:
In males: vas deferentia and seminal vesicles.
In females: vagina.

11. Superior surface: Completely covered by peritoneum. Related to:
In males: coils of ileum or sigmoid colon
In females: uterus
Male pelvis
Female pelvis

12. Infrolateral surfaces:
Related:
In front to the retropubic pad of fat & the pubic bones
Posteriorly lie in contact with obturator internus above and levator ani below
Retropubic fat
Accomodates distention of bladder
Continuous with fat in the anterior abdominal wall.
Rupture of bladder results in escape of urine to anterior abdominal wall

13. Neck: Lies inferiorly, and is the most fixed part of the bladder
Is related to lower border of symphysis pubis
In male, rests on the upper surface of prostate. Here, the smooth muscle fibers of the bladder are continuous with those of the prostate.
The circular muscle fibers thickened to form the sphincter vesicae

14. Interior of the Urinary Bladder
Mucous membrane thrown into folds except in the triangular region in the base of bladder, between the openings of the two ureters and the urethra. This region is called the ‘trigone’. Here The mucous membrane is always smooth even when the bladder is empty
Uvula vesicae, a small elevation in the mucous membrane, located just behind the internal urethral orifice. It is produced by the median lobe of prostate.

15. Blood & Nerve Supply Arterial supply: from internal iliac artery
Venous drainage: into internal iliac vein
Lymphatics: into internal iliac lymph nodes
The nerves form the vesical nerve plexus that contains:
Sympathetic fibers derived mainly from L1,2
Parasympathetic fibers derived from pelvic splanchnic nerves S2,3,4
Sensory fibers from the bladder are visceral and transmit pain sensation resulting from overdistention

16. The normal capacity of bladder is about 300-500ml.
As bladder fills, it becomes circular in shape & its superior surface bulges upward into abdominal cavity.
The peritoneal lining is peeled off the lower part of anterior abdominal wall and the bladder comes into direct contact with the anterior abdominal wall

17. Male Urethra About 8 inches (20cm) long
Extends from the neck of bladder to the external urinary meatus on the tip of the glans penis
Divided into three parts:
Prostatic
Membranous
Penile

18. Penile (spongy) urethra
Prostatic urethra
Length= 3 cm
Widest & most dilatable
Extends from neck of bladder inside prostate gland
Structures openings into prostatic urethra:
Ejaculatory ducts
Ducts of prostate gland
Penile (spongy) urethra
Length=16 cm
Narrowest part of whole urethra
Extends throughout penis & opens externally through external urethral orifice
Membranous urethra
Length=1 cm
Surrounded by external urethral sphincter

19. Female Urethra Length= 4 cm
Extends from neck of urinary bladder to open externally through the external urethral orifice (anterior to the vaginal opening)
Has only urinary function
Trigone

20. FLY HIGH
Thanks & Good Luck