Renal embryology Flashcards
From which germ layers is the renal system derived?
Mesoderm and endoderm
3 layers of mesoderm
Paraxial, intermediate and lateral plate (also divides into somatic and splanchnic)
From which germ layer is the uterine tube derived
Mesoderm
From which germ layer is the uterus and uterine canal derived
Mesoderm
From which germ layer is the vagina derived
Mesoderm and endoderm
From which germ layer is the urethra derived
Endoderm
From which germ layer is the external genitalia
Endoderm
Which structures make up the renal collecting duct system
Ureters, renal pelvis, calyces, collecting tubules
Which structures make up the renal excretory system
Nephron (renal corpuscle, glomerulus, Bowman’s capsule), PCT, LOH, DCT
Which structures are formed by the mesonephric system?
Mesodermal germ layer structures (renal tubules, ureter, reproductive ductal system, uterine canal, vagina)
Which structures are formed from the cloaca?
Ectodermal germ layer (urinary bladder, urethra, vagina, external genitalia)
What is the pronephros?
Functional kidney in primitive fish, derived from intermediate mesoderm
What is the mesonephros?
Functional kidney in advanced fish - intermediate mesoderm, forms mesonephric ducts
- Mesonephros form excretory tubules with glomerular capillaries surrounding which forms Bowman’s capsule - makes renal corpuscle which drains to mesonephric ducts
- Developing gonads lies on medial side of developing mesonephros, forming urogenital ridge
What is the metanephros?
Functional kidney in human
How is the collecting system formed?
- Ureteric bud from mesonephros penetrates the metanephric tissue or blastema
- Gives rise to ureter, renal pelvis, calyces
- Collecting tubules converge on minor calyces forming renal pyramids
How is the excretory system formed?
- Distal end covered by metanephric cap
- Cells of cap form renal vesicles
- Renal vesicles form S-shapes renal tubules
- At one end of tubules, forms glomerulus
- Glomerulus indents to form Bowman’s capsule
- Other end forms pathway from Bowman’s capsule to collecting units
- Renal tubules + glomeruli form nephrons
- Lengthening of excretory tubes forms convoluted tubules
What are the two embryonic structures from which the kidney is derived?
- Ureteric bud from mesonepohric duct gives rise to collecting system
- Metanephric blastema forms excretory units
When does urine production start?
week 12
Why do the kidneys not filter waste in fetus?
Placenta does
Why does the kidney ascend?
Body curvature, growth in lumbar and sacral regions
How does the blood supply to the kidney change as it ascends?
In pelvis = pelvis branch of abdominal aorta
When ascends = higher branches of aorta
Wilm’s tumour
Kidney cancer in kids <5
Caused by mutated WT1 gene on 11p13
WAGR
Wilms, Aniridia, Gondoblastoma and mental retardation, due to deletion in chromosome 11 that includes PAX6 and WT1 genes
Denys-Drash
Congenital nephropathy
renal failure, ambiguous genitalia, Wilm’s tumour
