HUBS192 Lecture 30 - Urinary System III, The Ureters, Bladder and Urethra Flashcards
what is transitional epithelium?
stratified rounded cells that flatten when stretched for protection
what are the ureters?
2 slender tubes that carry urine from the kidneys to the bladder that descend retroperitoneally through the abdomen and vertically from the hilum
where are the ureters located?
retroperitoneal
what moves urine to the bladder?
peristaltic waves
where do the ureters arise from?
arise from each renal pelvis at each hilum
what are the 3 layers of the ureter?
1) mucosa that consists of the lamina propria and the transitional epithelium
2) muscularis - inner longitudinal layer and outer circular layer
3) adventitia - outer covering of fibrous connective tissue
what is in mucosa layer of the ureter?
- lamina propria
- transitional epithelium
what is in the muscularis layer of the ureter?
- smooth muscle
- inner longitudinal circular layer
- outer circular layer
what is on the inner surface of the ureter?
folded protective protein plaques
is the muscularis of the ureter the same as the GI tract?
no because the inner layer is longitudinal (compared to an inner circular layer in the GI tract) and the outer layer is circular (compared to a outer longitudinal layer in the GI tract)
where does the ureters enter the bladder?
run obliquely through the wall of the bladder at the posterolateral corners
what is the effect of the ureters entering the bladder at an oblique angle?
act as sphincter/valve compressed by increased bladder pressure to prevent back-flow
what is the urinary bladder?
a collapsible muscular sac that stores and expels urine
what happens when the urinary bladder is empty?
when empty the bladder collapses along folds - rugae
what is the relationship between bladder expansion and pressure?
when full, the bladder expands without a great increase in pressure
what are the rugae in the urinary bladder?
folds that allow the bladder to expand
what does the bladder wall contain?
contains muscle for the expulsion of urine
what is the function of the urethra?
carries urine out of the bladder
what is the trigone?
triangular region between 2 openings of entry of the ureters and 1 opening for the urethra
what is the shape of an empty bladder and where is it located?
pyramidal in shape and lies within the pelvis
what is the shape of a filling bladder and where is it located?
as the bladder fills it become more spherical and expands superiorly into the abdominal cavity
where can the bladder be palpated?
above the pubic symphysis
where is the bladder located in males?
anterior to the rectum and superior to the prostate gland (wraps around the urethra)
where is the bladder located in females?
anterior to the vagina and the uterus (sits on top of the bladder)
what is the layer of muscle in the urinary bladder?
thick smooth muscle layer called the detrusor
what is the result of the contractions in the urinary bladder wall?
contractions to expel urine from bladder into urethra during urination
what are the 3 structures that protect the urinary tract?
1) transitional epithelium
2) protein plaques
3) entrance to bladder prevents backflow
what is the muscle that forms the wall of the bladder and what is its function?
detrusor muscle that expels urine
what is the urethra?
thin walled muscular tube that drains urine from the bladder out out the body
how does the epithelium change in the urethra?
- transitional epithelium near the bladder
- columnar epithelium with mucus glands to protect epithelium from urine
- stratified squamous near the external opening
how long is the female urethra?
approx. 5cm
is the urethra seperate from the reproductive system in females?
yes, the urethra is seperate from the reproductive system
how long is the male urethra?
approx. 25cm
is the urethra seperate from the reproductive system in males?
no, it part of the reproductive systems
what is the initial section of the male urethra surrounded by and what does it produce?
initial section is surrounded by the prostate gland and produces seminal fluid
what does the initial section of the male urethra produce?
seminal fluid
what are the 3 sections of the male urethra?
1) prostatic
2) membranous
3) spongy/penile
what is the internal urethral/urinary sphincter?
the junction of the bladder and the urethra that is an extension of a detrusor muscle that is under involuntary control
is the internal urethral/urinary sphincter under voluntary or involuntary control?
involuntary control
what is the external urethral/urinary sphincter?
located where the urethra passes through the urogenital diaphragm that is composed of skeletal muscle under voluntary control
is the external urethral/urinary sphincter under voluntary or involuntary control?
voluntary control
what is the basic process of urination?
- bladder fills with urine and expands
- AP from stretch receptors to brain
- urgency increases as signals increase
- internal sphincter relaxes
- conscious relaxation of the external sphincter
what is the motility pattern that moves urine down the ureter?
peristalsis
what are the 3 places in the urinary tract you would find transitional epithelium?
1) ureters
2) urinary bladder
3) initial part of urethra
