Session 2 - Lecture 1 - Development Flashcards
1 - SKIP
Development of the Urinary System
2 - Lecture objectives
Lecture objectives • The development of the kidney – intermediate mesoderm – pro-, meso- and meta- nephric kidneys – ducts • The development of the urinary bladder – the hindgut, allantois and cloaca – the urethra • Embryological bases for common congenital defects of the system
“1. take you through discrete dvlpmntal stages have to complete to allow us to develop a true functional water-conserving kidney (metanephros – metanephric kidney)
- also ureters and urethra, pick up some of the Repro unit thinking.
- Common congenital defects affecting the kidney and the urethra – focus in GW”
3 - Structures of the urinary system
Structures of the urinary system
• Pair of kidneys
• Each receive arterial supply from a direct branch of the abd. aorta
• Functional unit is the nephron
• Urine produced drains to the urinary bladder via the ureter
1- Pubic crest 2- External iliac artery and vein 3- Psoas fascia, Genitofemoral nerve 4- Psoas major, Femoral nerve 5- Iliacus, Lateral cutaneous nerve of thigh 6- Right and left common iliac arteries 7- Quadratus lumborum, Iliohypogastric and ilio-inguinal nerves 8- Subcostal artery and nerve, Transversus abdominis 9- Ureter 10- Hilum of right kidney 11- Right and left renal veins 12- Right suprarenal gland 13- Diaphragm 14- Inferior vena cava 15- Inferior phrenic artery 16- Hepatic veins 17- Central tendon of diaphragm 18- Celiac ganglion and trunk 19- Inferior phrenic artery and plexus 20- Posterior vagal trunk in esophageal hiatus 21- Adhesions 22- Left suprarenal gland 23- Spleen 24- Costodiaphragmatic recess 25- 10th rib 26- Hilum of left kidney 27- Superior mesenteric artery 28- Sympathetic trunk 29- Abdominal aorta 30- External oblique 31- Internal oblique 32- Transversus abdominis 33- Inferior mesenteric artery and vein 34- Testicular artery and vein 35- Ureter 36- Left common iliac vein 37- Testicular artery and vein 38- Ductus deferens (vas deferens)
“2. renal artery one on each side arises from abd. Aorta.
4. urine produced by nephron sitting inside parenchyma of kidney drains down through the posterior abdomen behind the peritoneum down to urinary bladder”
4 - 3 separate kidney systems form
3 separate kidney systems form • Organisation of intermediate mesoderm • 3 systems develop sequentially • Disappearance of one system marks the onset of development of the next developmental stage • 1st appears in the cervical region – the pronephros
“Separate.
- Yesterday looked at intermediate mesoderm for dvlpmnt of gonad, duct system in repro tract - so In the same region, urogenital ridge – where we focus our attention again.
- cascade of development, each system appears triggers onset of dvlpmnt of subsequent system and so on, so you can see it is important, although not own one of the systems remains at start? – but important to know for development of subsequent system and ultimately true kidney.”
5 - Urinary embryology
- Dorsal aorta
- Paraxial mesoderm
- Intermediate mesoderm
- Intercellular cavities in lateral plate
Dorsal
Ventral
Mesoderm: Somites, intermediate and lateral plate
- cloaca
- Gut tube
- pronephros
- mesonephros
- metanephros
“We are thinking about this region here, intermediate mesoderm of brain, trilaminar mesoderm - part of the mesoderm that sits between the somites and lateral mesoderm
Map out early embryo, so here’s our primitive gut tube, particularly interested in this region here the hindgut, so there’s the cloaca, common exit point for GI and repro and urinary system – all 3 systems draining into primitive gut tube
Reddish dots represent first formation of urinary system - really high up in neonate body, approx. where occiput is here – so Pronephric kidney, appears in neck region.
As development proceeds have development of the mesonephros, actually has a renal function, can’t conserve water but nevertheless primitive nephrons that carry out primitive function
And then finally we have the metanephros - our true kidney and that is the kidney that takes over function in fetal life, carries on producing urine during foetal life, importance of urinary function later on, that’s the sequence, in order to achieve development of this true, functional kidney capable of conserving water we need to complete successfully each of the preceeding stages.”
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