5.1 Embryonic development of KIDNEYS

Question 1

3 LAYERS in EMBRYO TRILAMNAR DISC at 18 days

Answer 1

ECTODERM
MESODERM
ENDODERM

Question 2

where do KIDNEYS originate from

Answer 2

INTERMEDIATE MESODERM
/ intermediate mesenchyme

Question 3

upon Folding of embryo, what does INTERMEDIATE MESODERM DIFFERENTIATE into

Answer 3

NEPHROGENIC CORDS

Question 4

In WEEK 5 intermediate mesenchyme has differentiated to form ducts and tubules which connect to a CAVITY known as the..

Answer 4

CLOACA

(remains connected to Yolk Sac by the ALLANTOIS)

Question 5

3 origins of KIDNEY DEVELOPMENT:

Answer 5

1. PRONEPHROS
   rudimentary and non-functioning
2. MESONEPHROS
   functions during early development
3. METANEPHROS
   forms the permanent/adult kidney

Question 6

when does the PRONEPHROS APPEAR

Answer 6

around 4TH WEEK but quickly degenerates

Question 7

PRONEPHROS quickly DEGENERATES to leave the … and what do these do

Answer 7

PRONEPHRIC DUCTS

• DRAIN CAUDALLING into the CLOACA
• PERSIST as ducts for the Mesonephros

Question 8

when does the MESONEPHROS appear

Answer 8

around 4th WEEK
CAUDAL TO PRONEPHROS (tail end)

Question 9

MESONEPHROS DIFFERENTIATES to FORM..

Answer 9

40 GLOMERULI with MESONEPHRIC DUCTS
that open into the pronephric ducts

Question 10

how long does the MESONEPHROS FUNCTION for before DEGENERATING

Answer 10

6-10 WEEKS

Question 11

what do the TUBULES of the MESONEPHROS become after

Answer 11

EFFERENT TUBULES of the TESTES

Question 12

what becomes the TRUE KIDNEY

Answer 12

METANEPHROS

Question 13

what DEVELOPS from the MESONEPHRIC DUCT

Answer 13

URETETIC BUD

• branches off to meet the intermediate mesenchyme in the METANEPHRIC BLASTEMA

Question 14

URETERIC BUD branches off to meet the intermediate mesenchyme in a specialist area called..

Answer 14

METANEPHRIC BLASTEMA

URETETIC BUD & METANEPHRIC BLASTEMA is the PRIMORDIUM of the KIDNEY

Question 15

URETERIC BUD BIFURCATES (divides) to form..

Answer 15

RENAL PELVIS
-> CALYCES
-> COLLECTING DUCTS

metanephric blastema differentiates around the tubules to form the kidney

Question 16

some of the GENES involved in KIDNEY development

Answer 16

WT1
PAX1

Question 17

4 STAGES of NEPHRON DEVELOPMENT:

Answer 17

1. MESENCHYMAL CELLS form a VESICLE
2. VESICLE becomes S-SHAPED and CONNECTS to URETERIC BUD
3. TUBULES develop CUP-SHAPED CAPSULE
4. TUBULES ELONGATE and GLOMERULUS becomes ROUND and MATURE

Question 18

what happens to KIDNEYS after development due to tail end of embryo growing away

Answer 18

RENAL ASCENT

MIGRATE UPWARDS to the SUPRARENAL GLANDS

(gonads descending at same time)

Question 19

when KIDNEYS are still in the PELVIS where is the BLOOD SUPPLY coming from

Answer 19

COMMON ILIAC ARTERIES (/external)

Question 20

BLOOD SUPPLY of KIDNEYS in their permanent position

Answer 20

directly from AORTA

(older blood supplies disintegrate as kidneys ascend)