HISTOGENESIS OF MUSCLE LAYERS OF HUMAN URINARY BLADDER

2016-05-20T01-56-23Z
Source: International Journal of Current Research and Review
Shinde Reshma B., Laqeeue Mohammad, Ukey Rahul K., Diwan Chaya V..
Background: Urinary bladder is an organ of considerable importance in mammals, being a site where urine is collected before micturition and without undergoing any significant exchange of water or ions with surrounding. Urinary epithelium (urothelium) is unique in being non-reabsorptive and non-secretory in nature. The earlier studies on the development of urinary bladder were mainly on its gross anatomical features. Objectives: 1) To note structural differentiation and maturity of muscularis externa layer which it attains at different stages of development to show the adult picture. 2) To compare and contrast differences between different age groups and with previous studies and available literature. Material and Method: 50 aborted human fetuses (29 females and 21 males) of different gestational age from 9th week onwards were collected, urinary bladder were taken out and fixed in a fixative. Blocks of tissues were made from bladder wall proper, trigone & bladder neck and processed to get sections which were stained with 1) Haematoxylin and Eosin 2) Massons trichrome stain. Results: Beginning with 12th week, muscularis externa showed well developed circular muscle layer and a thin inner longitudinal layer in the form of thin, scattered bundles. Outer longitudinal layer appeared as discrete, nonuniform bundles of muscle fibres by 13th week. All three layers were seen well developed and thick by 16th week and found thickest by 32nd week with slight variations in their arrangement. Muscle layer thickness at bladder neck and trigone increased progressively from 18th wk onwards. Conclusion: Muscular layer in bladder wall showed all three layers progressively increased in thickness and indistinctly well developed from 16th week onwards and found thickest at 32nd week. Thus Histogenesis of urinary bladder in this instance may represent a powerful tool to delineate structure function relationship.


from Scope via xlomafota13 on Inoreader http://ift.tt/1OD6bBi
via IFTTT