Urinary System Embryology

Question 1

what does the outpouching that carries waste to umbilical cord called?

Answer 1

allantois - outpouching from before the cloaca

waste product leaves from here

Question 2

what is the terminal portion of the gut in an embryo called? what does this go on to form?

Answer 2

cloaca - gets seperated to form urogenital sinus and rectum

Question 3

what does the urogenital sinus go on to form?

Answer 3

urinary bladder and urethra (more proximal portion of the allantoid becomes obliterated when umbilical cord is cut)

Question 4

Where is the definitive kidney formed form?

Answer 4

Metanephric mesoderm (part of the intermediate plate mesoderm)

Question 5

Where is the ureteric system/collecting system of the kidney formed from?

Answer 5

the ureteric bud (growing out of the mesonephric bud)

Question 6

what does the cranial part of the ureteric bud form?

Answer 6

the pelvis of the kidney

Question 7

what do the collecting tubules empty into?

Answer 7

the minor calyces -> major calyces -> kidney pelvis

Question 8

what occurs during the development of the nephron in the metanephric kidney?

Answer 8

• little vesicles develop into tubules
• blood vessels invaginate the proximal end of the tubules (glomerulus)
• by around week 32 the nephrons are essentially made
• collecting duct is made form ureteric bud

Question 9

what is the difference between the urinepherous tubule and the nephron?

Answer 9

Question 10

what is the urinepherous tubule formed form?

Answer 10

metanephric mesoderm (nephron) and the urinary bud (collecting duct)

Question 11

where are the final kidneys initially formed? what happens to them?

Answer 11

formed at region of pelvis and they ascend

Question 12

what can happen in the anomoly where one of the 6 segmental arteries the aorta gives to the kidney does not disintegrate after the kidneys ascent?

Answer 12

it usually continues to vascularise the kidney and is usually not an issure however it can :

• press down on teh ureter and cause and cause obstruction

Question 13

what are some abnormal sites that teh ureter may open into?

Answer 13

• reproductive system
• anal canal
• rectum

all of these need correction as tehy can cause infection

Question 14

what other anomolies may be found in kidneys?

Answer 14

Question 15

what forms the kidneys? what are the different kidney made?

Answer 15

intermediate mesoderm develops the kidneys:

• pronephros at 4 weeks (neck region)
• mesonephros at week 5-9 (trunk region)
  
  • working kidney drained to cloaca
  • recycled to make reproductive system
• definitive kidney - metanephros