Flashcards in Lecture 19 DA Deck (47):
Name 4 paired viscera in the pelvis for males.
Name 4 unpaired viscera in the pelvis for males.
Are paired viscera at the midline?
Some are, others are non-midline.
Where do paired viscera refer pain to?
The same side of the body.
Where do unpaired viscera refer pain to?
To the midline, as they have nerve supply from both sides of the spinal cord.
What are the layers of the ureters?
-Serosa, most superficial
-Muscularis, circular and longitudinal
Does continence depend on gravity? How is this clinically relevant?
No, one can pee upside down. If a surgeon is unsure of a structure, a peristaltic wave can be felt.
How do the ureters pierce the bladder?
Posterolaterally, entering obliquely.
What is the ureter called when within the bladder?
Intramural ureter, a functional sphincter.
Where does the ureter enter the bladder?
Through ureteral orifices.
What happens when urine fills the bladder?
Bladder walls stretch, and close the intramural ureter, which is a functional sphincter.
Where does the ureter get its blood supply?
From every vessel it comes close to.
What crosses the ureter in males and females?
In males, it is crossed only by the vas deferense, just as it enters the bladder.
In females, uterine arteries cross over it at the pelvic brim, also just as it enters the bladder.
Aside from that, it is the most anterior structure in both males and females.
What is a consequence of a high calcium diet on the urinary system?
High calcium can result in uretery calculi - kidney stones.
They can lodge at narrowings of the ureter:
Proximal to intramural ureter
Why are uretery calculi (kidney stones) so painful?
When they lodge at a narrowing, they cause the muscle to spasm, causing referred pain to overlying dermatome, the loin area, up to the scrotum in males, and vulva in females.
Are pain fibres involved in uretery calculi symathetic or parasympathetic?
They are sympathetic, referring to T11-L1 dermatomes.
Why can't opioids be used as an analgesic in uretery calculi pain?
It stimulates further ureter muscle spasm, worsening the pain.
What are two anatomical variations in the ureter?
1% - bifed ureter, that terminate as one before reaching the bladder, endangered in surgery.
0.2% - pelvic horseshoe kidney, kidneys are merged inferiorly.
How does pelvic horseshoe kidney occur?
As kidneys develop in the pelvic cavity, they start at the midline, but as the body elongates, the can't get to the appropriate spot and the horseshoe structure stays within the pelvis.
Is there any pathology associated with a pelvic horseshoe kidney?
No, but it can be mistaken for another structure.
Where does the bladder lie in women? Why is this significant?
Lies anteriorly, resting in part on the vagina. Vaginal prolapse means less support for the bladder,
Does the bladder have a peritomeum?
Yes, it does on its superior surface, which descends berween the rectum and uterus, and between the bladder and uterus. As the bladder fills, the perotineal coat is pushed upwards.
What happens to the bladder neck? What supports it?
It becomes continuous with the urethra. It needs most support from the vagina, as well as some from the levator ani.
What happens to continence of urine during childbirth and why?
When the levator ani is stretched, it leads to urine incontinence.
What is the urachus? What does it become?
At embryonic stages, the apex of the bladder is connected to the umbilicus via a duct, called urachus.
What becomes the median umbilical ligament?
Before it degenerates after birth, the urachus is called the median umbilical ligament, and connects the bladder's apex to the umbilicus. It is patent/open, and urine passes from the bladder out the umbilicus.
How is the urachus clinically signifcant?
It can remain patent in adulthood, urine will leak out of the umbilicus.
Is the bladder abdominal or pelvic?
It is abdominal in children as their pelvis is too small. They can pee longer distances due to their abdominal muscles. It sinks after 6 years.
What are the layers of the bladder?
It has a mucosa lining it, and its muscle layer is called the detrusor urinae muscle.
What is the trigone?
Triangular area inferiorly, in the posterior mid portion of the bladder, where the ureters enter. Made of smooth muscle, different to detrusor urinae, which can stretch, the trigone can't.
How is the detrusor urinae different to the trigone?
Detrusor urinae can stretch, the trigone cant.
What is the internal urethral sphincter? Do females have one?
Females do not have one. It is found at the end of the trigone, and prevents backflow of semen into the bladder from the prostatic urethra, rather than preventing urinary backflow.
What is the Turp procedure, and what is a consequence of this?
When the prostate is removed, but can damage the internal urethral sphincter. People who have this have backfllow of seminal fluid into the bladder.
What is a consequence of prostate hypertrophy?
A tight bladder neck, difficulty in micturition.
What nerves are involved in the micturition reflex?
Involves parasympathetic fibres via S2-S4 for detrusor contraction.
Internal urethral sphincter relaxing - sympathetic T12-L1, involuntary.
External urethral sphincter, levator ani - pudendal nerve S2-S4.
What happens when there is a significant obstruction along the urethra?
A catheter puncture is neede, called suprapubic puncture.
Bladder must be full to stretch the peritoneum, so there is no danger of puncturing the perotineum.
What are the dangers of suprapubic punctures?
There is a danger of puncturing the:
Retropubic space (veins here)
Blood vessels of the bladder
Where is the urethra in females?
Shorter in females, and anterior to the vagina, below the clitoris, but is variable.
Where is the urethra in males?
It passes through the prostate, called prostatic urethra, and then called membranous urethra after passing levator ani. It is longer in males.
How does urethral catherisation differ in males and females?
Simpler in females as its shorter.
Males must be navigated, and is possible to pierce the posterior wall of the urethra, causing a fistula, and abnormal hole.
What is a fistula?
An abnormal hole. One can occur during urethral catheterisation, where the posterior wall of the urethra can be pierced.
What is the clinical significance of no internal urethral sphincter in females?
They are more at risk of urinary incontinence.
How many curvatures does the rectum have?
What is the purpose of transverse rectal folds?
Aids in faecal (Theres no oil here, move on) storage and passage of air.
What is the perineum?
When the rectum becomes continuous with the anal canal, called perineum.
What is found superior to the perineum?
Ampulla recti. Faeces are stored here before excretion.