RT Book, Section
A1 Maygarden, Susan
A2 Reisner, Howard M.
SR Print(0)
ID 1115280592
T1 Urologic Pathology of the, Lower Urinary Tract, Male GU System and Kidney
T2 Pathology: A Modern Case Study
YR 2015
FD 2015
PB McGraw-Hill Education
PP New York, NY
SN 9780071621564
LK accessmedicine.mhmedical.com/content.aspx?aid=1115280592
RD 2024/04/24
AB REVIEW  OF  NORMAL  HISTOLOGY  OF  THE  LOWER  URINARY  TRACT  "QUICK  REVIEW"The  outflow  of  the  kidneys  (renal  pelvis,  ureters,  bladder,  and  urethra)  comprises  the  lower  urinary  tract  (Figure  13-1).  The  basic  histology  is  that  all  are  lined  by  urothelium  (transitional  epithelium),  which  covers  a  connective  tissue  layer  of  lamina  propria,  a  variably  thick  layer  of  smooth  muscle  (muscularis  propria)  and  adventitia  (Figure  13-2).  Urothelium  is  specialized  epithelium  that  is  multilayered  with  large  surface  superficial  cells  (umbrella  cells),  which  can  change  shape  as  the  bladder  dilates  and  contracts.  These  contain  specialized  cell  junctions  that  are  resistant  to  permeation  by  urine.  Beneath  this  are  five  to  six  layers  of  smaller  urothelial  cells.  The  muscularis  propria  is  well  developed  in  the  bladder,  and  coordinated  contraction  of  this  muscle  (detrusor  muscle)  helps  in  emptying  the  bladder.  Muscle  is  less  prominent  in  the  ureters  and  the  urethra.  The  distal  urethra  is  lined  by  squamous  epithelium,  which  is  continuity  with  the  squamous  epithelium  of  the  external  genitalia.  Both  the  male  and  female  urethra  contain  mucinous  glands  in  their  walls.