renal development

Question 1

List the names of the sets of kidneys throughout development

Answer 1

The pronephros (about 3 to 4 weeks), the mesonephros (about 4 weeks-2 months), and the metanephros (about 5 weeks to maturity).

Question 2

Where do all of the kidneys develop from

Answer 2

the nephrogenic cord within the urogenital ridge- Mesodermal cells within the nephrogenic cord develop into groupings of cells called nephrotomes that are located in each somite during embryo segmentation.

Question 3

Describe development of mesonephric duct

Answer 3

The nephrotomes vesiculate and join laterally forming first the pronephric duct, then as nephrotomes further caudally add to it it becomes the mesonephric duct (week 5). This grows even more caudally and the pronephros degenerates, leaving the mesonephric/wolffian duct.

Question 4

What is Wolffian body

Answer 4

development of urogenital ridge that protrudes into coelom

Question 5

Discuss development of paramesonephric duct

Answer 5

An invagination of coelom wall which runs along the length of the wolffian body.

Question 6

Male vs female ducts

Answer 6

Wolffian/mesonephric ducts develop into male reproductive system (degrade in females) while paramesonephric ducts /mullerian ducts develop into female repro system (degrades in males)

Question 7

Describe development of metanephros- ureteric bud

Answer 7

at 5-6 weeks, A bud of epithelial cells from a portion of mesonephric duct forms (ureteric bud) and it is eveloped by the metanephric blastema (which will develop into parts of the kidney). The ureteric bud branches to form the ureter, renal pelvis and major/minor calyces.

Question 8

Describe development of collecting ducts and tubules

Answer 8

The branches of the ureteric bud branch into tubules called Malpighian pyramids. The epithelia of these outgrowths
will become the collecting ducts of the kidney, then further branch into collecting tubules.

Question 9

Describe development of glomeruli and nephron

Answer 9

Mesoderm at tips of collecting tubuless organize into a metanephric spheroid, then vesiculates to form a metanephric vesicle. The vesicle elongates to form a tubule, then folds into shape of “S” as it becomes the metanephric tubule. Meanwhile, renal artery and vein branch btw the Malpighian pyramids to form the intralobar vessels… all the way to the glomerular capillaries, efferent arterioles and vasa recta.

Question 10

What does the urogenital sinus develop from

Answer 10

Cloaca endoderm

Question 11

When does urogenital sinus separate from hindgut

Answer 11

6-7 weeks

Question 12

What does the urogenital sinus develop into

Answer 12

bladder and urethra

Question 13

discuss kidney ascent

Answer 13

As ureteric bud elongates, kidneys ascend from sacral region into retroperitoneal location.

Question 14

What happens to the allantois

Answer 14

degenerates to form a fibrous cord called the urachus

Question 15

What does the mesonephric duct form?

Answer 15

epididymis and ductus deferens in males

Question 16

What does the paramesonephric duct form

Answer 16

uterus and oviducts