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Development „ After lateral folding… of under coelomic epithelium Urogenital Systems „ Lengthwise column „ Urinary system : ANHB 2212 – 2008 „ Nephric tubules Avinash Bharadwaj „ Open in the coelomic cavity, later…

„ Draining duct

The Kidney Story… Pronephros

„ 8 to 10 “segments” – cervical „ Developmental and evolutionary „ Cell groups… „ Successive parts of intermediate mesoderm craniocaudal sequence

„ Begins high up „ Disappear completely „ Three sets of “kidneys” „ Do not function as kidneys (only some species of fishes) „ First, middle and ‘other’ (final).

„ Pronephros, mesonephros and metanephros

Mesonephros Step-by-step …

„ Thoracolumbar region Sectional view… „ Tubules

„ Duct : (Wolffian) Aorta Mesonephric duct „ Caudal end :

„ Æ urogenital part nd „ 2 month events „ Functional for a short period

1 Mesonephros disappears Metanephros

„ Tubules regress „ Caudal end of nephrogenic cord „ Duct persists… …put to some use! „ Duct : diverticulum from mesonephric duct Æ Ureteric bud

„ Migrates cranially

Metanephros Collecting System Pelvis Major calyces Minor calyces

Major calyces „ Metanephric cap Pelvis Æ Urine-forming part Pelvis „ Major and minor calyces „ Ureteric bud Major calyces „ Collecting ducts Æ Collecting system „ Metanephric cap Æ tubules

The Nephron The Nephron…

„ Cell clusters around blind ends „ Glomerulus of tubules „ Parts of the tubule PCT „ Hollow DCT „ „ Thin part Æ Bowman’s capsule Proximal convoluted

„ Rest Æ tubule „ Loop of Henle Loop „ Distal convoluted

„ Communication essential !

2 Ascent of Kidney Reproductive Organs

„ Blood vessels : „ Gametogenic cells… successive sources „

„ Fused kidneys : „ Mesonephric and Arrested by IMA x paramesonephric ducts

„ descend

„ Common plan… M Differentiation P

Male System Female System

„ “Gubernaculum” M „ Paramesonephric duct

„ Mesonephric duct „ Fusion : caudal part P Æ Uterus

„ Cranial : Tube

„ Uterine abnormalities.

Female System Final Picture Uterine tube „ Descent stops in the Müllerian duct Ligament pelvis * of * „ Gubernaculum Æ Fibrous cords Ovary „ Ligaments : Round Uterus : ligament Fused Müllerian „ Of ovary of uterus ducts „

3 Implications of Descent

„ Blood supply

„ Veins

„ Nerves

„ Lymphatics

„ and its contents

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