Development of the Urinary system

Question 1

the urogenital system develops from what type of the mesoderm

Answer 1

intermediate mesoderm

Question 2

the intermediate mesoderm forms a longitudinal ridge that is called ?

Answer 2

urogenital ridge

Question 3

the kidneys develop in what type of sequence somatotopically

Answer 3

cranial to caudal

Question 4

what are the 3 developing kidney systems in chronological order

Answer 4

• pronephros
• mesonephros
• metanephros

Question 5

when and where does the pronephros develop ?

Answer 5

day 21-24

-cranially in the cervical segments of the intermediate cords

Question 6

which kidney system is rudimentery and which becomes the adult kidney

Answer 6

pronephros - rudimentery/nonfunctional

metanephros - becomes functional kidney

Question 7

when and where does the mesonephros develop

Answer 7

weeks 5-10

-thoracic and lumbar segments of the intermediate mesoderm

Question 8

is the mesonephros functional ?

Answer 8

Yes, produces and drains urine during weeks 5-10

Question 9

in the mesonephros what is the structure that drains the urine produced leading to the bladder

Answer 9

mesonephric duct (Wolfian duct)
- or nephrogenic duct

Question 10

what develops into the primordial nephron ?

Answer 10

consolidation of about 40 mesonephric tubule

Question 11

the mesonephric duct extends caudally untill it fuses with ____, making up the ____ portion of the bladder

Answer 11

cloaca, posterior portion

Question 12

what initiate the formation of the uteric bud ?

Answer 12

canalization of the mesonephric cord

Question 13

what is the adult derivative of the uteric bud

Answer 13

metanephric diverticulum

Question 14

canalization of the mesonephric duct occurs in what direction somatotopically

Answer 14

caudal to cranial

Question 15

what are the 2 componets of the metanephros

Answer 15

• Collection portion

- excretory portion

Question 16

when and where does the uteric bud develop

Answer 16

week 5 in the distal portion of the mesonephric duct

Question 17

the formation of the uteric bud induces the sacral region of the intermediate mesoderm to form what ?

Answer 17

metanephric blastema

Question 18

the collecting portion of the metanephros develops from what ?

Answer 18

uteric bud

Question 19

the excretory portion of the metanephros develops from what ?

Answer 19

metanephric blastma

Question 20

what does reciprocal induction mean with reference to the metanephros

Answer 20

it means that the uteric bud is needed to “induce” nephron differentiation

• aka to induce the metanephric blastema
• if the uteric bud doesnt develop, then rest of kidney doesnt develop

Question 21

what parts of the adult kidney arise from the collecting portion of the metanephros

Answer 21

• ureter
• renal pelvis
• major/minor calyces

Question 22

what parts of the adult kidney arise from the excretory portion of the metanephros

Answer 22

• bowmans capsule
• PCT
• loop of henle
• DCT

Question 23

when do the kidneys start to ascend and what causes them to ascend

Answer 23

around week 6-9

-growth in length of the embryo forces them cranially

Question 24

As the kidney ascends does it drag its original vasculature with it, or develop new blood supply strategies

Answer 24

Does NOT drag

-develops new renal a..

Question 25

What are the 3 potential clinical malformations if the kidneys do not ascend correctly

Answer 25

1 - pelvic kidney -ectopic/out of place
2 - horeshoe kidney
3 - supernumery arteries - >1 renal aa. entering hilum
**2 and 3 not cause long term effects***

Question 26

what is the cloacal membrane divided by what ?

Answer 26

urorectal septum

Question 27

the urorectal septum divides the cloacal membrane into ?

Answer 27

• ventral urogenital sinus

- dorsal anorectal canal

Question 28

what are the 3 parts of the ventral urogenital sinus and what do they become

Answer 28

• vesicle part - anterior portion of bladder
• pelvic part - urethra
• phallic part - spongy urethra (men)

Question 29

what is the posterior aspect of the bladder made up of ?

Answer 29

-distal portions of the mesonephric duct

Question 30

what is the trigone and where can it be found

Answer 30

a triangular region of pulled down mesonephric ducts forming the posterior aspect of the bladder

Question 31

what makes up the posterior vs. anterior aspects of the bladder

Answer 31

posterior - trigone of mesonephric ducts

anterior - vesicle part of ventral urogenital sinus

Question 32

what develops from the pelvic part of the urogenital sinus in women

Answer 32

entire urethra and vagina

Question 33

what develops from the pelvic part of the urogenital sinus in men

Answer 33

prostatic and membranous urethra

Question 34

what develops from the phallic part of the urogenital sinus in men

Answer 34

spongy urethra

Question 35

what are the 3 possible types of clinical malformations when the intraembryonic allantois does close off properly from the cloacal membrane

Answer 35

1 - urachal cyst - pocket of swelling when both ends are pinched off
2 - urachal sinus - closure at 1 end and open on the other
3 - urachal fistula - allantois not closed at either end resulting in dripping urine from umbilicus

Question 36

what is exstrophy of the bladder and how does it occur

Answer 36

where the mucosal lining of the bladder is outside the body wall b/c the closing off of the external oblique did not occur on the anterior abdominal wall