Part 13: Urinary Bladder and Ureters in the Pelvis Flashcards
What is arrangement of smooth muscle in bladder?
Whorls and spirals - the detrusor muscle.
Developed for contraction not peristalsis
What is the mucous membranes of the bladder?
Thick and lax lined by transitional epithelium (stratified) which undergoes transformation from cuboidal at rest to flatter and squamous appearing when stretched). No glands. No muscularis mucosae.
What is the shape of the bladder?
Globular/ovoid when distended
Undistended more pyramidal in shape
Describe where the base, neck and apex of bladder are
Base: posterior surface - below level of rectovesical pouch, only upper part covered by peritoneum. Attached to anterior vagina in females.
Apex: Remains of urachus forming median umbilical ligament. Points to pubic symphysis
Neck: Lowest part of bladder, where base and inferolateral surfaces meet, pierced by urethra
What is the trigone?
Triangular area at base of bladder, between internal urethral orifice and ureteral orifices. 2.5cm apart in empty bladder, can be 5cm in distended bladder.
What is the interureteric bar?
Transverse ridge connecting ureteric orifices
What is the uvula vesicae?
Indentation in trigone from projection of median lobe of prostate, just above internal urethral orifice
What is the blood supply to the bladder?
Superior and inferior vesicle arteries, plus some small branches from obturator, inferior gluteal, uterine and vaginal (IIA)
What is the venous drainage of bladder?
Does not follow arteries.
Forms plexus which converges on vsicoprostatic plexus in the groove between badder and prostate - drains to internal iliac veins
What is the lymphatics drainage of the bladder?
Follows arteries back to IIA and EIA
What is the nerve supply of bladder?
Parasympathetic fibres via pelvic splanchnic nerves which supply detrusor muscles.
Sympathetic form L1,2 via SHP and pelvic plexus - largely vasomotor but also to trigone and internal sphincter. Pain reaches spinal cord via both tracts.
Why do males have an internal sphincter that females do not have?
Perhaps prevents retrograde ejaculation into bladder in male - > not required in female
Where does the bladder develop from?
Endodermal tissue.
Incorporation of mesonephric ducts (mesodermal) form trigone
Where does the ureters enter the pelvis?
Over pelvic brim at bifurcation of CIA, over EIA and in front of IIA.
What is the ureter path in the pelvis?
Crosses obturator nerve, artery and obliterated umbilical artery. Turns forwards and medial at ischial spine to enter bladder at upper lateral angle.
In Male crossed by DD and uterine artery in female
