|BLADDER & URETER - ANATOMY & APPLIED ANATOMY
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|Author:||lakshmidr [ 18 Sep 2019 13:41 ]|
|Post subject:||BLADDER & URETER - ANATOMY & APPLIED ANATOMY|
ANATOMY OF BLADDER
The bladder is a part of is the urinary system between the ureters and the urethra. It plays two main roles namely
Serving as a temporary reservoir of urine
Contracting of bladder muscle aids expulsion of urine via urethra
The adult bladder is located in the anterior pelvis and covered by extraperitoneal fat and connective tissue.
The bladder separated from the pubic symphysis by the space of Retzius or retropubic space.
The dome of the bladder is covered by peritoneum, and the bladder neck is fixed to adjacent structures by true ligaments of the pelvis and reflections of the pelvic fascia.
The main part or body of the bladder is supported inferiorly by the pelvic floor muscles in females and the prostate in males with lateral support from the obturator internus and levator ani muscles.
In females, the bladder neck serves as the internal sphincter
The neck of the bladder is attached to the prostate in the male; in the female it lies directly overlies the pelvic fascia around the short urethra
From the apex of the bladder, the medial umbilical ligament, or the urachal remnant, travels along the anterior abdominal wall to the umbilicus.
TRIGONE OF BLADDER
The trigone is a triangular area in the floor of the bladder bounded ventrally by the bladder neck and dorsolaterally by the openings of the right ureter and left ureter. The ureters transport urine from the kidneys to the bladder enter the bladder at its trigone
The bladder is supplied by the superior and inferior vesical branches of the internal iliac artery. The veins of the bladder form a vesical plexus that drains into the internal iliac vein
APPLIED ANATOMY OF URINARY BLADDER
1. Stress Incontinence
In the females, the most important support for the bladder is the levator ani muscle which forms the pelvic floor. A difficult labor and especially if forceps are used, the bladder neck gets stretched and the normal angle between the posterior wall of the bladder and the urethra is lost. This injury results in stress incontinence which causes leakage of urine when the woman strains excessively, coughs or laughs.
To treat stress incontinence the urethra should be supported so that the angle between the bladder neck and the urethra is restored. This can be corrected permanently by surgically elevating the urethra and the bladder neck by sutures or using a fascial sling or artificial tape.
2. Palpation of Bladder
Bimanual palpation of the empty bladder is an important method of bladder examination. In the male, one hand is placed on the anterior abdominal wall just above the pubic symphysis, and the gloved index finger of the other hand is introduced gently into the rectum. The wall of the urinary bladder can be felt between both hands. Similarly, in the female, an abdominovaginal examination can be done.
3. Urinary retention
In elderly men, urinary retention is commonly caused by obstruction to the urethra by enlargement of the prostate, either benign or cancerous. Urinary retention is very uncommon in females and the only anatomic cause of urinary retention is inflammation around the urethra eg herpes
4. Suprapubic aspiration
In cases of acute retention of urine, when catheterization is not possible, a needle is introduced into the
bladder through the lower part of the abdomen above the symphysis pubis, without entering the peritoneal cavity. This is a simple method of draining the bladder in an emergency
ANATOMY OF THE URETER
The ureter is 25cm long and comprises the abdominal, pelvic and intravesical parts.
The abdominal ureter lies on the medial edge of the psoas muscle (which separates it from the tips of the transverse processes of L2–L5)
It enters the the pelvis at the division of the common iliac artery in front of the sacroiliac joint. Ante
The right ureter is covered anteriorly at its origin by the second part of the duodenum and is lateral to the inferior vena cava and behind the posterior peritoneum. It is crossed by the testicular (or
ovarian), right colic, and ileocolic vessels.
The left ureter is similarly crossed by the testicular (or ovarian) and left colic vessels and then passes above the pelvic brim, crossing the common iliac artery immediately above its bifurcation.
The pelvic ureter crosses the front of the internal iliac artery and turns forwards and medially to enter the bladder.
In the male it lies above the end of the seminal vesicle and is crossed superficially by the vas
deferens. In the female, the ureter passes above the lateral fornix of the vagina 12mm and lies below the broad ligament and uterine vessels
The intravesical ureter passes obliquely through the wall of the bladder for about 2 cm; the bladder muscle and obliquity of the ureteric course produce a valve-like arrangement at the termination of this duct.
APPLIED ANATOMY OF URETER
1. The ureter is readily identified in life by its thick muscular wall and undergoes worm-like writhing movements, especially if squeezed or gently stroked
2. The ureter is relatively narrowed at three sites:
• At the junction of the pelvic ureter and abdominal part,
• At the pelvic brim, and
• At the ureteric orifice (narrowest of all).
An ureteric stone is most likely to get impacted at one of these three levels
3. In a plain x-ray of the abdomen, one must look for an ureteric calculus along the tips of the transverse processes, in front of the sacroiliac joint swings outwards to the ischial spine and then medially to the bladder. An opaque shadow along this line should raise suspicion of calculus (see fig)
4. Avoiding injury to ureter during surgery
This happens commonly during vaginal or abdominal hysterectomy when the ureter is accidentally divided, crushed or excised. Precautionary ureteric catheterisation helps to avoid such accidents as the catheters enable easy identification of the ureters
|Author:||Badri [ 28 Sep 2019 01:09 ]|
|Post subject:||Re: BLADDER & URETER - ANATOMY & APPLIED ANATOMY|
Pictures showing narrow areas in ureter and x-ray showing calculus in right ureter
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