lecture 30 Flashcards
what type of epithelial cells would you find in the nephron loop?
Cuboidal with microvilli brush border at PCT and simple squamous cuboidal with a few microvilli at DCT
name the two capillary beds associated with the nephron?
glomerular and peritubular
which type of nephron is important for the production of concentrated urine?
juxtamedullary
What type of epithelium is in the bladder?
transitional epithelium
What is transitional epithelium?
stratified rounded cells that flatten when stretched
what is the purpose of stratified rounded epithelium in the bladder?
for protection. so urine does not leak into underlying tissue when stretched
How many ureters do you have?
2
Where do the ureters arise from?
the renal pelvis at each hilum
What is the role of ureters?
carry urine from kidneys to bladder
what helps move urine to bladder?
peristaltic waves
what are the three layers of the ureter?
transitional epithelium forming mucosa
muscular (inner longitudinal and outer circular)
Adventitia (outer covering, fibrous tissue)
Is the muscularis of the ureter the same as the GI tract?
No it is swapped around. in the GI tract it is an inner circular and outer longitudinal
How do ureters enter the bladder?
run obliquely through the wall of the bladder at the posterolateral corners
How does the bladder act as a sphincter/valve?
when bladder expands the wall begins to compress on the ureter to prevent back flow
what is the role of the urinary bladder?
collapsible muscular sac that stores and expels urine
What happens to the bladder when it is empty?
collapses along folds called rugae
how much can the bladder expand to when full?
~500mL
what is the role of the urethra?
carries urine out of the bladder?
Why is the bladder wall made of muscle?
to expel urine
what is the trigone?
triangular region between 2 openings of entry of ureters and 1 opening for urethra
what happens as the bladder fills?
becomes more spherical
expands superiors into abdominal cavity
can be palpated (felt) above pubic symphysis
What shape is an empty bladder and where does it lie?
pyramidal and lies within the pelvis
where is the female bladder located?
anterior to vagina and uterus
Where is the male bladder located?
anterior to rectum. Superior to prostate gland
Structure of the bladder wall?
folded into rugae
mucosa of transitional epithelium
which smooth muscle layer called detrusor
What is the detrusor?
longitudinal, circular and oblique smooth muscle fibres that contract to expel urine from bladder into urethra during urination
name three structures that protect the urinary tract?
transitional epithelium
protein plaques
entrance to bladder preventing backflow
name the muscle that forms the wall of the bladder and its function?
detrusor muscle to expel urine
How does the epithelium change in the urethra?
from transitional near bladder then columnar then stratified squamous near opening
What protects epithelium from urine?
mucus glands
What are the differences between female and male bladder?
Females is ~5x shorter and seperate from reproductive system while the males is
The initial section of the male urethra is surrounded by?
The prostate gland
what are the three regions of the male urethra?
prostatic
membranous
spongy/penile
what are the two urethral sphincters?
internal and external
What is the difference between the internal and external urethral sphincter?
Internal is at junction of bladder and urethra and is made of detrusor muscle, involuntary control
the external is distal and made of skeletal under voluntary control
What controls urgency of urination?
expansion of bladder is detected by stretch receptors which increase in frequency with filling
name three places in the urinary tract you would find transitional epithelium?
ureters
urinary bladder
initial part of urethra
