Lecture 30 Ureter, bladder, urethra Flashcards
whats Transitional epithelium?
- Stratified, rounded cells
- Flatten when stretched
- For protection
where do ureters arise from each?
renal pelvis at each hilum
whats ureters?
Slender tubes that carry urine from kidneys to bladder
where do ureters descend?
retroperitoneally through abdomen, vertically from hila
in the ureters what moves urine to bladder?
Peristaltic waves
whats the 3 layers of ureters?
– Transitional epithelium – Muscularis – Adventitia – Folded protective protein plaques on inner surface
what does the muscularis consist of in ureters?
inner longitudinal, outer circular
what does the Adventitia consist of in ureters?
outer covering of fibrous connective tissue
where do the ureters run?
obliquely through the wall of bladder at its posterolateral corners
Ureters run obliquely through the wall of bladder at its posterolateral corners. what does it act as?
sphincter/valve: compressed by increased bladder pressure to prevent backflow
whats the urinary bladder?
Collapsible muscular sac
Stores and expels urine
what happens when the urinary bladder is empty?
the bladder collapses along folds (rugae)
what happens when the urinary bladder is full?
the bladder expands without great increase in pressure (~500ml)
what do ureters do?
-carry urine from kidneys to bladder
what do rugae do?
-Folds that allow bladder to expand
what does the urethra do?
-carries urine out of bladder
what do the bladder wall have?
-contains muscle for expulsion of urine
what is the trigone?
-triangular region between 2 openings of entry of ureters and 1 opening for urethra
when the bladder is empty?
bladder is Pyramidal
Lies within the pelvis
As the bladder fills
Becomes more spherical
Expands superiorly into abdominal cavity
Can be palpated above pubic symphysis
where is the male bladder?
– Anterior to rectum
– Superior to prostate gland (wraps around urethra)
where is the female bladder?
– Anterior to vagina and uterus
what does the urinary bladder wall consist of?
Folded into rugae for expansion
Muscosa of transitional epithelium
Detrusor (thick smooth muscle)
whats the detrusor?
thick smooth muscle
Longitudinal, circular and oblique fibres
Contractions to expel urine from bladder into urethra during urination
Name three structures that protect the urinary tract.
Transitional epithelium, protein plaques, entrance to bladder to prevent backflow
Name the muscle that forms the wall of the bladder. What orientations of muscle fibres are present here?
Detrusor muscle, circular longitudinal oblique fibres
whats the urethra?
- Thin walled muscular tube
- Drains urine from the bladder out of the body
- has mucus glands
what epithelium makes up the urethra?
the epithelium changes so whats it
near bladder
middle
near external opening
Transitional = near bladder
Columnar = middle
Stratified squamous = near external opening
why does the urethra have mucus glands?
to protect epithelium from urine
Describe the female Urethra
– shorter (~5cm)
– separate from reproductive system
describe the male urethra
– longer (~25cm)
– part of reproductive system
– initial section surrounded by prostate gland (produces seminal fluid)
– 3 sections: prostatic, membranous, spongy/penile
whats the 3 sections of the male urethra?
prostatic,
membranous,
spongy/penile
what surrounds the initial section of the male urethra?
by prostate gland (produces seminal fluid)
whats the 2 urethral sphincter?
Internal urethral/urinary sphincter
External urethral/urinary sphincter
whats the Internal urethral/urinary sphincter?
Junction of bladder and urethra
Detrusor muscle
Involuntary control
whats the External urethral/urinary sphincter?
Located where urethra passes through the urogenital diaphragm
Skeletal muscle
Voluntary control
Urination
what happens when Bladder fills with urine and expands?
AP from stretch receptors to brain
Urgency increases as signals increase
Internal sphincter relaxes
Conscious relaxation of external sphincter
Which of the following statements is INCORRECT about the bladder?
A. Detrusor muscle forms the bladder wall
B. It is lined with transitional epithelium
C. It is a collapsible sac which stores and expels urine
D. The trigone is a triangular area between the openings of the ureter and two urethras
E. When empty, the bladder collapses along folds called rugae
The trigone is a triangular area between the openings of the ureter and two urethras
What motility pattern moves urine down the ureter? How does the muscle in the ureter differ from the GI tract?
Peristalsis.
opposite to GI tract: inner longitudinal, outer circular
Name three places in the urinary tract you would find transitional epithelium.
Ureters, Urinary bladder, initial part of urethra
