Lecture 19 RH Flashcards
What are the principles underlying referred pain of abdominal viscera?
Pain from paired viscera is often referred to a side of the body.
Pain from unpaired viscera is referred to the midline.
What are the principles underlying tubular viscera?
tubular viscera typically consist of a sphincter at both ends and could contain a physiological sphincter within them.
WHat muscles do ureters contain in their walls?
longitudinal and circular.
How does urine pass through the ureters?
via peristalsis.
How long are ureters?
typically 25cm with half its length in the pelvis.
How does the ureter regulate what enters the bladder?
The ureter pierces the bladder posterolaterally and closes when the pressure inside the bladder increases in response to being filled up with urine. This is carried out via a functional sphincter.
What layers do the ureters consist of?
Serosa coat
muscle coat consisting of both circular and longitudinal muscle
mucosa layer inside
What are the blood vessels that supply the ureters?
The ureters receive a segmental arterial supply, which varies along its course.
The upper part of the ureter closest to the kidney is supplied by the renal arteries.
The middle part of the ureter is supplied by the common iliac arteries, direct branches from the abdominal aorta, and gonadal arteries (the testicular artery in men or ovarian artery in women).
The lower part of the ureter closest to the bladder is supplied by branches from the internal iliac arteries,as well as: Superior vesical artery Uterine artery (in women only) Middle rectal artery Vaginal arteries (in women only) Inferior vesical artery (in men only)
What are ureteric calculi and how do they develop?
Ureteric calculi are kidney stones and they develop as a result of a high calcium diet.
Where is the most common site of ureteric calculi accumulation?
at the narrowings for the kidney (including the one at the pelvic brim).
What causes pain to be felt when experiencing ureteric calculi? Where is the pain felt?
distension of the ureters causes muscle spasms and this causes sensory neurons to fire signals to the brain causing referred pain to side, back and lower abdomen. In some cases it can be referred to the scrotum (in males) or the vulva (in females)
Which sympathetics do visceral afferents of ureters follow?
T11 - L1
How are ureteric calculi treated?
they are left alone to pass through urine. Patients are often given painkillers for the pain, however, opioids cause spasms so they aren’t prescribed.
What are some variations that can be seen in kidneys?
Some people have double ureters that either fuse before reaching the bladder or fuse with the bladder. (1% of population)
Some people have pelvic horseshoe kidneys that are fused in the pelvis (0.2% of the population)
Where is the bladder located relative to the rectum and the vagina?
anterior to the rectum and posterior to the vagina
How is the bladder held in place?
Bladders neck is continuous with the urethra and is held in place at the levator ani by the neck.
What happens to the contents of the bladder if levator ani was stretched?
Urinary incontinence.
What is the median umbilical ligament? What is the clinical significance of this ligament?
A midline fold that is remnant of the urachus that connects the bladder’s apex to the umbilicus. It could cause urine to leak from the belly button.
Where is the bladder located in children? Why?
In the abdomen because children’s pelvises are too small to hold the bladder
What are the contents of the bladder wall?
a layer of muscle known as detruser muscle.
A triangular trigone made up of the ureteral and urethral orifices.
What is the function of the detruser muscle?
The detruser muscle can stretch to accommodate lots of urine without contracting until the fluid reaches a critical point.
Where does the female bladder lie?
Female bladder lies above levator ani.
Where is the internal urethral sphincter located?
Within the prostate of men (not found in women)
What is the function of the internal urethral sphincter?
it prevents backflow of semen into the bladder.
What does hypertrophy of the bladder cause?
hypertrophy of the bladder creates a tight bladder which makes urination difficult.
What causes the bladder to contract during micturition reflex?
parasympathetic fibers act on detruser muscle to contract after bladder cells stretch.
What spinal segments are involved in the micturition reflex?
S2 - 4
How does voluntary urination take place?
Pudendal nerve innervates the levator ani and the external urethral sphincter to contract and allow urine to be expelled.
What is the treatment to people who can’t expel their urine?
supra pubic puncture can be made
What structures are endangered by a suprapubic puncture?
Peritoneal cavity
Intestines
uterus
Retropubic space
blood vessels of bladder mucosa
Inferior epigastric vessels
What can be done to someone who has lost their nerve innervation of urination?
Installation of an artificial sphincter. (contains button in scrotum)
Where does the GI tract terminate within the pelvis?
at the rectum which extends from S3 to the tip of the coccyx
What covers the rectum?
Rectum contains 3 transverse folds and tough fascia
