10.1 Embryology

Question 1

from which layer of the trilaminar disc does the urinary system develop?

Answer 1

intermediate mesoderm

Question 2

the pronephric duct extends down to where?

Answer 2

cloaca

Question 3

first functioning filter of the kidney

Answer 3

mesonephrod

Question 4

mesonephros cant do what?

Answer 4

conserve water and therefore alter urine composition

Question 5

steps of formation of metanephros

Answer 5

1. mesonephric duct forms ureteric bud
2. ureteric bud GFs induce undifferentiated intermediate mesoderm to develop metanephros

ureteric bud forms collecting system
metanephric blastema forms nephrons

Question 6

what’s in the collecting system formed by ureteric bud?

Answer 6

minor+major calyces, renal pelvis, ureters

Question 7

formation of horseshoe kidneys

Answer 7

poles fuse, so ascension is incomplete, caught by mesenteric artery

Question 8

consequence of duplication defects

Answer 8

ureteric bud splits curing ectopic ureteral openings

Question 9

from weeks 5-6 what happens to mesonephric duct?

Answer 9

absorbed into bladder to form trigone

Question 10

what forms from the mid part of the urogenital sinus?

Answer 10

urethra in females
prostatic and membranous urethra in males

Question 11

what forms from the lower part of the urogenital sinus?

Answer 11

clitoris in females
spongy urethra/ penis in males