Kidney development; 3.31

Question 1

What does the urogenital ridge develop from?

Answer 1

Intermediate mesoderm

Question 2

What happens during the pronephric phase?

Answer 2

Pronephric duct grows towards the cloaca (genitalia)…pronephric duct later degenerates

Question 3

What does the pronephric duct become during the mesonephric phase?

Answer 3

Mesonephric or Wolffian duct

Question 4

What do the mesonephric tubules become in males?

Answer 4

Mesonephric tubules become the efferent ductules of the testes (connect the testis to the ductus deferens)

Question 5

What does the mesonephric duct become in males?

Answer 5

Ductus (vas) deferens ad ureteric bud (metanephric diverticulum)

Question 6

What does the mesonephric duct become in females?

Answer 6

Ureteric bud only

Question 7

What does the ureteric bud (metanephrogenic diverticulum) grow into?

Answer 7

Ureteric bud grows into the intermediate mesoderm (metanephrogenic mesoderm/blastema)

Question 8

What does the ureteric bud initiate?

Answer 8

Metanephric diverticulum initiates formation of the definitive/permanent kidney (metanephros)

Question 9

What does the metanephric kidney consist of?

Answer 9

Ureter
Renal pelvis
Major/minor calyces
Collecting duct

Question 10

What do the nephrons derive from?

Answer 10

Metanephric tubules (from metanephric mesoderm)

Question 11

What are uriniferous tubules?

Answer 11

Nephrons and collecting ducts

Question 12

Know that nephrons and collecting ducts develop from different sources

Answer 12

Collecting tubes = metanephric diverticulum

Neprons = metanephric tubules

Question 13

What is the original supply to the metanephric kidney?

Answer 13

The common iliac…then the body grows caudally and the kidneys “rise”

Question 14

What causes renal agenesis?

Answer 14

Failure of ureteric bud and metanephric mesoderm to interact

Question 15

Which kidney more commonly does not form? Which gender is more likely to be born with only one kidney?

Answer 15

The left kidney is more likely to NOT develop

Renal agenesis is more common in males

Question 16

When should renal agenesis be suspected?

Answer 16

In infants with a single umbilical artery

Question 17

What causes duplicated or branched ureters and supernumerary kidney?

Answer 17

Bifurcation of ureteric bud prior to interacting with metanephric mesoderm

Question 18

What causes a pelvic kidney?

Answer 18

Metanephric kidney fails to migrate from pelvis

Metanephric mesoderm fused to form one kidney

Question 19

What is it called when one kidney crosses over? and fuses to the other kidney? and the arteries are on the medial side?

Answer 19

Crossed ectopic kidney
Fused kidney
Non-rotation

(all three can happen simultaneously)

Question 20

Where do horseshoe kidneys get stuck during ascension?

Answer 20

IMA

Question 21

Polycystic Kidney Disease (PCKD)…remember it

Answer 21

It’s not hard

Question 22

What is seen with multicystic dysplastic kidney disease?

Answer 22

Abnormal dilations of [thin segments] of nephrons

Question 23

What typically causes a congenital hydroureter? Is it generally bad?

Answer 23

An obstruction of the ureter at the ureteropelvic junction (usually)

Not usually bad…hydronephrosis results

Question 24

What is the urogenital sinus continuous with?

Answer 24

The allantois…which extends into the body stalk (umbilical cord)

Question 25

What does the allantois form?

Answer 25

The urachus (becomes the median umbilical ligament)

Question 26

What does the vesicle part of the urogenital sinus form?

Answer 26

The urinary bladder (continuous with the allantois)

Question 27

What does the pelvic part of the urogenital sinus become in males?

Answer 27

The bladder neck and prostatic urethra (endoderm)

Question 28

What does the pelvic part of the urogenital sinus become in females?

Answer 28

The entire urethra

Question 29

What does the rest of the urethra grow from in males?

Answer 29

The penile urethra grows from the phallic part of the urogenital sinus (ectoderm)

Question 30

What gets incorporated into the posterior wall of the developing urinary bladder?

Answer 30

Mesonephric ducts and ureteric bud

Question 31

The connective tissue and smooth muscle of the urinary bladder and urethra are derived from what?

Answer 31

Splanchnic (visceral) mesenchyme (mesoderm)

Question 32

What forms urchal cysts?

Answer 32

Epithelial cells that do not degenerate

Question 33

What is it called when the urachus drains via the umbilicus?

Answer 33

Urachal sinus

Question 34

What causes a urachal fistula?

Answer 34

Patent urachus…urine dribbles from urachus

Question 35

What causes megacystis or megalcystis?

Answer 35

Posterior urethral valves that block the outflow of urine from the bladder (only in males)

Question 36

What is a possible result of megacystis or megalocystis?

Answer 36

End-stage renal failure (20% of all ESRF d/t megacystis or megalocystis)

Question 37

What does the cranial part of the urogenital ridge give rise to?

Answer 37

Adrenocortical primordia

Question 38

What do mesothelial cells located on the posterior abdominal wall b/w the root of the dorsal mesentery and the developing gonad become?

Answer 38

Adrenal cortex

Question 39

What accounts for the large size of the fetal adrenal gland? what happens to during the first year?

Answer 39

Fetal cortex is big, but it regresses during the first year

Question 40

What replaces the fetal cortex?

Answer 40

Permanent cortex (from mesenchymal cells)

Question 41

What does the adrenal medulla develop from?

Answer 41

Neural crest cells (neuroectoderm)

Question 42

What happens with adrenogenital syndrome?

Answer 42

Mutation in P450c21 (steroid 21-hydroxylase gene)

Question 43

What happens due to reduced steroid hormone production with adrenogenital syndrome? What is the net result?

Answer 43

Increased ACTH causes adrenal hyperplasia causing overproduction of androgens