Embryology of the urinary tract

Question 1

When does the renal system start to develop?

Answer 1

week 5

Question 2

How many phases are there in renal embryological development?

Answer 2

3

Question 3

Where does embryo develop from in the embryo?

Answer 3

sacral part of the embryo -> the intermediate mesoderm

Question 4

Kidneys in adults are placed where

Answer 4

posterior abdominal wall

Question 5

What are the 3 parts of the mesoderm?

Answer 5

paraxial mesoderm
intermediate medoserm
lateral mesoderm

Question 6

What is the intermediate mesoderm?

Answer 6

Neck region

Question 7

What are pronephros?

Answer 7

Lower cervical region of the grwoing embryo -> get segmentation there to form the prnephros

they wont develop completely functional things, they do occurr in the cervical region

Question 8

What is the mesonephros?

Answer 8

It is the 2nd stage of development

segmentation along the longitudinal duct, it does function for a period unlike pronephros

forms a connection to the vasculature and then binds to the mesonephric duct

Question 9

What is the importance of having a functional kidney at birth?

Answer 9

urine production is important as it helps in the production of the amniotic fluid

Question 10

What do mesonephric tubules do?

Answer 10

40 paords produced cranionephrapllythey regress at the end of week 5
20 pairs remain at L1 - L3

differentiate to form the glomerulus and excretory units
function between weeks 6-10
then they regress

Question 11

When do the mesonephric tubules regress?

Answer 11

Week 10

Question 12

Do the nesnephric tubule regress completely in men or women?

Answer 12

in women

Question 13

What happens if th eureteeric bud fails to develop btw the cloaca and the metanephric blastema or is short what happens?

Answer 13

one side - can live with it

both sides - can’tdeal with it

Question 14

mesonephric duct

Answer 14

forms the collecting tubule

Question 15

What does the ureteric bud form?

Answer 15

the collecting system:
ureteer
renal pelvis
mahor calyces
minor calyces
1-3 million collecting ducts

Question 16

How does the kidney feel in the embryo?

Answer 16

lobular structure, not smooth

Question 17

How are multiple collecting ducts, major and minor calyces formed?

Answer 17

the dcts keep growing but at the end forms a aperiod of intususseption. where the multiple major calyces come together and form a big major calyces

similarly again growth and intusussception to forms minor calyces

multiple channels are formed and they cause the formation of millions of collecting ducts

Question 18

What are the various components of the nephron?

Answer 18

Bowmens capsule
proximal convoluted tubule
ascending and descending loop of Henle
distal convoluted tubule

Question 19

Formation of the nephron

Answer 19

as a new branch is formed its tip is associated with metanephric tissue caps

helps to feedback to the collecting system (communication system) and its tells collecting tubules to collect fluid and it tells the metanephric tissue to form new nephrons

arrange themselves as a vescile -> an epithelial wall around a hollow spacem it’l l keep growing one towards the vasculature and the other end towards the ureteric bud

the nephron develops as a different structure from the collecting duct and then as it develops the wall btw it and the collecting duct breaks down

Question 20

How does the kidney reach its adult location?

Answer 20

It moves up during the process of development
ascends from the pelvis to L2 during the wees 6-9
new vessels form as the kidney

Question 21

What is the arterial supply to the kidney at the beginning and later on?

Answer 21

in the beginning common iliac artery

then as it ascends it gets new branches

Question 22

Is arterial variation common or rare in the kidney?

Answer 22

It is quite common to find accessory arterial supply

Question 23

What are a few of the developmental anomalies in the development?

Answer 23

The kidney doesn’t ascend and remains in the pelvic region - pelvic kidney

Horseshoe kidney - ascends anterior to the aorta (fine for a period of time but once the anterior branches of the aorta coome out - it gets trapped under the lowest branch/ IMA, the kidney will be fine but can jave associated problems)

Question 24

What is the embryological development

Answer 24

endodermal origin

Hindgut endoderm

Question 25

Urogential sinus divides into what?

Answer 25

bladder- most cranial part
pelvic urethra
expansion of the definitive urogential sinus

Question 26

Allantois

Answer 26

temporary communication

posterior aspect of the anterior abdominal wall - can find the remnant of the allantois

Question 27

Incorportation of the mesonephric ducts into the pposterior wall importance

Answer 27

formation of the trigone

is coming from the mesonephric duct, as a result of its different origin it is non-contractile and the musculature is different

Question 28

Failure of the segregation of the cloaca leads to what?

Answer 28

males in urethra
females along with the development of vagina

leads to the communication btw the systems