Abdominopelvic Development Flashcards
What mesoderm forms the kidneys and gonads?
Intermediate mesoderm
What two things does the intermediate mesoderm split into?
Nephrogenic region
Genital ridge
Note:
Found posterior to the intraembryonic cavity, but in contact with it.
What are the 3 nephros? Which one becomes the actual kidney?
Pronephros
Mesonephros
Metanephros (kidney!)
What does the pronephros become?
Nothing. It starts out in the cervical region and then rescinds.
What does the mesonephros become?
It first helps filtrate in the thoracic and lumbar region. The mesonephros rescinds, but the mesonephric duct stays connected to the cloaca.
What does the metanephros become?
Kidneys!
Starts out in the pelvis and then ascends.
What is the ureteric bud and its purpose?
It is an outgrowth of the mesopephric duct. It extends into the intermediate mesoderm and INDUCES the formation of the metanephros into kidneys.
Note:
It is the sole signal for the kidneys’ formation.
As the metanephric kidneys ascend, what happens to the mesonephric ducts?
They descend, carrying the UNDIFFERENTIATED gonads with them.
How does the blood supply of the kidneys and mesonephric ducts change as they move?
The kidneys get blood supply from a more superior source, aka the aorta. They lose their lower arteries.
The mesonephric ducts just keep their OG blood supply from the aorta.
What can happen to the blood supply of the kidney as it develops early?
It can get multiple renal arteries, some of which are retained at birth.
What do we call the extra renal arteries?
Polar arteries, if they enter via the superior or inferior poles of the kidney.
What is agenesis of the kidney? What causes it?
Failure of a kidney to develop.
Caused by failure of the ureteric bud to form.
What happens if the ureteric bud kinda splits in two but not fully off just a single stalk?
You can get a bifid ureter going from your kidney, and the other kidney will fail because the blood supply will not rescind from its lower region.
What happens if the ureteric bud splits in two partially but share the same stalk overall?
You can have two kidneys on a single side whose ureters will combine inferiorly.
What happens if you have two distinct ureteric buds on one side with two distinct stalks?
Two kidneys with two distinct ureters on a single side.
What happens if a kidney moves to the opposite side while its ascending?
Your kidneys could fuse on one side!
What happens if your kidney ascend but they are right next to each other?
They can fuse in the pelvis, preventing them from ascending further.
Why can horseshoe kidneys not ascend?
They get stuck at the inferior mesenteric
What is a polycystic kidney?
It is a inherited disease that causes many cysts to form on the kidney, leading to renal insufficiency.
What two ducts are important in reproductive embryology and are found next to the genital ridge?
Mesonephric duct
Paramesonephric duct
What do Y chromosomes produce?
SRY, previously known as testes-determining factor.
What is the default gender of the embryo unless signaled?
Female!
What is the origin of the testes?
Mesonephric ducts (Wolffian) (male meso)
Note:
Paramesonephric will rescind.
What is the origin of the ovaries?
Paramesonephric ducts (Mullerian)
Note:
Mesonephric will rescind