Urinary system (embryology)

Question 1

What gives rise to most organs of both the urinary and genital systems?

Answer 1

Intermediate mesoderm (except urogenital sinus)

Question 2

What are the derivatives of the urogenital sinus?

Answer 2

Urinary bladder, urethra and associated glands

Question 3

What 3 kidney systems are formed in a cranial-caudal sequence?

Answer 3

1. Pronephros
2. Mesonephros
3. Metanephros

Question 4

Pronephros

Answer 4

Tubules degenerate
Duct remains and empties into the cloaca (nonfunctional)

Question 5

Mesonephros

Answer 5

Mesonephric tubules and mesonephric duct
Functional kidney in adult fish and amphibian
Functional transitory in mammals

Question 6

What does the pronephric duct become?

Answer 6

Mesonephric duct
Remains and forms the male duct system (epididymus, ductus deferens and seminal vesicle)
Filtrate transported

Question 7

Mesonephric tubules

Answer 7

Most degenerates
Few remain and become efferent ductules
Blood transported

Question 8

Metanephros

Answer 8

Functional kidney in adult reptiles, birds and mammals
Originates from metanephric bud and metanephric blastemal

Question 9

Metanephric bud (ureter bud)

Answer 9

Grows out of mesonephric duct near the cloaca (distal end)
Forms ureter, renal pelvis and collecting ducts

Question 10

Metanephric blastemal

Answer 10

Condensed mesenchymal tissue in front of ureter bud
Forms the nephron: renal corpuscle, PT, Henle’s loop and DT

Question 11

Cloaca

Answer 11

Common chamber for digestive, urinary and genital systems in the mammalian embryo
Lined by endoderm

Question 12

Urorectal spetum

Answer 12

Divides cloaca into rectum and anal canal dorsally and urogenital sinus ventrally

Question 13

Urogenital sinus

Answer 13

divided into vesicular, urethral, pelvic and phallic parts

Question 14

What does the vesicular part of the urogenital sinus become?

Answer 14

Urinary bladder which cranially continues as urachus (intraembryonic/ distal part of the allantoid)

Question 15

Where do the mesonephric duct and ureter open initially?

Answer 15

Dorsal wall of the bladder

Question 16

What happens with differential growth of the dorsal wall of the bladder?

Answer 16

Ureter opening moved cranially creating a trigone region that anchors the ureter to the bladder and urethra
Mesonephric duct opens caudally

Question 17

Pelvic urethra in males

Answer 17

Continuous with the urinary bladder
Penile urethra incorporated into the penis
Bulbourethral gland develops from this part of the urethra

Question 18

Where does the prostate gland develop?

Answer 18

from Urethral epithelium

Question 19

All derivatives of the urogenital sinus are _______________

Answer 19

Endodermal

Question 20

Hydronephrosis

Answer 20

Results from blockage in the ureter
Embryological origin: blockage in the collecting system leadint to fluid-filled cysts

Question 21

What does a double ureter lead to?

Answer 21

Ectopic ureter or ureterocele

Question 22

Incontinence in females

Answer 22

If ureter opens proximal to the urethralis muscle

Question 23

Patent urachas

Answer 23

Results form the failure of allantoic stalks to close at birth