Kidney embryology

Question 1

mammal develop 3 pairs of excretory organs

they are:

Answer 1

pronephroi
mesonephroi
metanephroi

Question 2

pronephroi

Answer 2

pretty much disappears

ball disappears, only the duct remains n becomes the mesonephric duct aka nephrite duct aka woffian duct

Question 3

mesonephroi

Answer 3

mostly disappears as well, only leaving a few bits that becomes a few bits n pieces of the reproductive tract in females n males

acts as the interim kidney till permanent kidney is formed

Question 4

where do kidneys develop from?

Answer 4

from intermediate mesoderm

Question 5

metanephroi

Answer 5

becomes the kidney

starts growing around wk 5

Question 6

wen do nephrons start to form?

Answer 6

nephrons start to form at around 9 wks.

n neprhongenesis stops at around 36 wks

Question 7

what happens with regards to metanephroi?

Answer 7

a little orange duct aka UTERIC BUD
comes off the woffian duct and grows towards the 
little blob of purple which is purple mesenchyme
 and penetrates to it. basically the little 
orange bud comes off, grown into n penetrates
the metanephric mesenchyme and then molecular signalling 
bw those 2 is gonna make the kidneys

Question 8

CONGENTIAL ABNORMALITY CONCEPT

Answer 8


if the bud doesnt come out at the right time

out of the right place

doesnt come out at all 

heads off in the wrong direction

that mesenchyme will die 

mesenchyme needs survival factors from the bud,
if it doesnt
get it,
that mesenchyme will die and no kidney will form on that side


btw, from a lot of studies, we found that this purple mesenchyme (theres lots
of mesenchyme in body) but its this one that is the only one that can make 
kidneys

Question 9

more details about kidney formation

Answer 9

tips of Uteric bud branches tell MM (metanephric mesenchyme ) to make nephrons

and 
MM tells UB to branch

Question 10

uteric bud gives rise to

Answer 10

like like tubal tree of the kidney i.e.:

collecting ducts, calyces, pelvis, ureter

Question 11

metanephric mesenchyme gives rise to

Answer 11

nephon

interstitium

Question 12

CAKUT =

Answer 12

Congenital Anomalies of the Kidney

and Urinary Tract

Question 13

VUJ obstruction=

Answer 13

Obstruction at vesicoureteric (VUJ) junction (aka at put where ureter join bladder)

where uerter 
doesnt come into
 bladder at the right angle n size n stuff

get back flow of urine all the way to kidney
can get hydroureter( Dilated ureter) n hydronephrosis (Dilation of the renal pelvis)

Question 14

PUJ obstruction

Answer 14

-= bw pelvis of 
kidney n ureter

urine backs up into kidney, n kills nephrons

Question 15

causes of CAKUT

Answer 15

mutations of genes (e.g. the BMP4 gene)

enviro influences eg maternal diet

physical obstruction of ureter somehow

Question 16

BMP4

Answer 16

Inhibitor of

Ureteric Budding and Branching Morphogenesis