11/20 Development Of Urinary System Flashcards
Formation of multiple sets of kidneys is in weeks?
4-8
Relocation of kidneys in urinary development happens in week?
9
Significant urine formation in urinary development happens in week?
11
Nephrogenesis occurs when prenatally?
Through week 36
When is the critical period for kidneys?
Most of human gestation (through week 36)
Fewer nephrons is associated with an increased risk for?
Hypertension
After birth, the glomerular filtration rate increases rapidly due to
decreased renal vascular resistance and increased renal blood flow
What is the general process of renal development?
Clusters of cells and ducts form, connected to cloaca
Columns of tissues use ducts and develop primitive, temporary nephrons
Kidneys form in pelvic region (at caudal end of ducts) and develop permanent nephrons
Kidneys relocate to their final positions
Cloaca is divided and part of it forms urinary bladder
During the urogenital ridge stage of renal development what is the state of sexual development?
Embryo is in undifferentiated state of sexual development, phenotypically identical regardless of genetics
What is the urogenital ridge and what does it contain?
Elevated intermediate mesoderm on either side of the dorsal aorta, along the posterior abdominal wall
Contains: Nephrogenic cord, Gonadal ridge
What does endoderm do in the urogenital ridge of renal development?
Endoderm forms epithelial lining and glands of the urinary bladder
Neural crest cells may play a minor role
How many sets of kidneys develop in weeks 4-5? How many of these become the permanent kidneys?
3 sets develop
1 set becomes permanent kidneys
What is the pronephroi set of kidneys? where are they?
Practice set of kidneys, used to develop a duct system
• On same plane as pericardial cavity
What are the three sets of kidneys that develop? In which weeks?
Weeks 4-5
Pronephroi, mesonephroi, metanephroi
What are the mesonephroi set of kidneys?
Temporary set of kidneys, used until the metanephroi are complete
What are the metanephroi set of kidneys?
Permanent set of kidneys
When are the pronephroi present? What is the purpose?
Present only in week 4
Purpose is to create tubular structures to be used later
What do the pronephroi contain?
Nonfunctional cell clusters in cervical region
Pronephric ducts
What are the pronephroi nonfunctional cell clusters made of? Do they persist?
made of pronephric tubules that degenerate
Where do the pronephric ducts run? Do they persist?
run from pronephric tubules to cloaca
persist and are used by mesonephroi
When are the mesonephroi present?
Appear late week 4
Degenerate after week 11
What is significant about week 11 in relation to renal function?
Urine formation contributes to amniotic fluid
What do the mesonephroi consist of?
Long columns of tissue caudal to pronephros
Made of mesonephric nephrons and tubules
Are the mesonephroi functional?
temporarily functional until metanephroi take over in week 11