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Year 2 - Renal (DP) > Embryology > Flashcards

Flashcards in Embryology Deck (33):
1

What germ layer do the kidneys originate from?

Mesoderm

2

When do the pronephros form?

In the 4th week of gestation

3

Where do the pronephros form?

Cervical region

4

What part of the pronephros persists?

Duct

5

How many mesonephros are produced and in what direction?

40 tubules produced craniocaudally

6

When do the mesonephros regress?

By the end of the 5th week of gestation

7

When the mesonephros regress, what is left and what do they do?

Leave 20 pairs (L1-L3):
- Differentiate in excretory units
-> Function weeks 6-10 then regress

8

When do the metanephros appear?

~5 weeks gestation

9

When do the metanephros begin to function?

~9-11 weeks gestation

10

What do the metanephros form?

The permanent kidney

11

What two structures form the metanephros and where do they originate from?

Ureteric bud:
- Protrusion from mesonephric duct
Metanephric blastama:
-From the mesonephric duct

12

In regards to the metanephros, when do the ureteric buds sprout and where from?

Day 28 of gestation
From distal mesonephric ducts

13

In regards to the metanephros, when does the metanephric blastema sprout and where from?

Day 32 of gestation
Ureteric buds penetrate sacral intermediate mesoderm

14

What is the process of development from the ureteric bud?

Ureteric bud -> Ureter -> Renal pelvis -> Major calyces -> Minor calyces -> Collecting ducts

15

What part of development of the ureteric bud is a dichotomous division?

Renal pelvis -> Major calyces

16

What does the metanephric blastema form?

Metanephric blastema -> Metanephric cap -> Metanephric vesicle -> Bowman's capsule:
-> PCT
-> Loop of Henle
-> DCT

17

Where do the kidneys initially develop? When do they reach their end position?

In pelvis
Reach end position by week 9

18

In what direction do the hila of the kidneys point during weeks 5 and 6?

Anteriorly (in pelvis)

19

When do the kidneys reach the abdomen and what direction do the hila face then?

~Week 7
Hila face medially

20

What happens to the kidneys as the embryo grows caudally?

Kidneys start to lie:
- Retoperitoneally
- At L1 level

21

How can the general blood supply of the kidney be described?

By closest aortic branches

22

What vessels initially supply the kidney?

Median sacral nerve and temporary aortic branches

23

What happens to the temporary aortic branches when kidney reaches final position?

Tend to regress (can persist -> Accessory renal arteries)

24

What is a pelvic kidney?

When one kidney fails to ascend

25

What is the process by which a horseshoe kidney forms?

Inferior poles of metanephroi meet and fuse before ascent:
- Trapped beneath inferior mesenteric artery

26

What is the cloaca?

Hindgut endoderm

27

What forms the cloaca?

Rectum
Primitive urogenital sinus:
- Bladder
- Pelvic urethra
- Definitive urogenital sinus

28

Where do the mesonephric ducts incorporate into and what do they form?

Into posterior bladder wall
Form:
- Epididymis
- Vas deferens
- Seminal vesicle

29

What is the urachus?

The closed remnant of the allantois, a duct between the bladder and the yolk sac

30

What is a urachal sinus?

Urachal lumen persists at upper part:
- Opens at umbilicus

31

What is a urachal fistula?

Urachal lumen persists along entire length:
- One end open in the bladder
- One end open at umbilicus
-> Urine discharged through umbilicus

32

What is a urachal cyst?

Small part of lumen remains patent:
- Each end closed
-> Forming median umbilical ligament
Secretory activity of epithelium remains active:
- Cystic dilatation

33

What is the normal remnant of the urachus?

Median umbilical ligament