Development of the Urinary System

Question 1

both the urinary and genital systems (urogenital system) develop from common ____ known as ____

Answer 1

mesodermal ridge; intermediate mesoderm

Question 2

intermediate mesoderm bulges into intraembryonic coelmic cavity creating the _____

Answer 2

urogenital ridge

Question 3

the urogenital ridge differentiates into:

Answer 3

• nephrogenic cord/ridge (lateral)

- genital ridge (medial)

Question 4

through lateral folding, the nephrogenic cord becomes ____

Answer 4

retroperitoneal

Question 5

three slightly overlapping kidney systems develop in ____ to ____ sequence

Answer 5

cranial; caudal

Question 6

three kidney systems

Answer 6

1. Pronephros (rudimentary, nonfunctional)
2. Mesonephros (function for a short time during early fetal period)
3. Metanephros (forms the permanent kidney)

Question 7

pronephros appear early ____ and degenerate by the end of this week

Answer 7

week 4

Question 8

pronephros in segmented _____ in the ____ region; never functional in humans

Answer 8

intermediate mesoderm; cervical

Question 9

mesonephros appear early week ___ in ___ and ____ segments of intermediate mesoderm

Answer 9

4; thoracic/lumbar

Question 10

in the mesonephros, urine is produced and drains along the _____ to the ____

Answer 10

mesonephric (Wolffian) duct; cloaca/bladder

Question 11

in week 5, the ___ segments of the mesonephros start to regress, but the mesonephric kidney continues functioning until week ___

Answer 11

thoracic; 10

Question 12

mesonephric ducts extend into lower lumbar and fuse with ____, contributing to _____

Answer 12

cloaca; posterior bladder

Question 13

in the mesonephros, canalization begins ____ and grows ____

Answer 13

caudally; cranially

Question 14

when the mesonephric duct hits the cloaca, it initiates _____ growth

Answer 14

ureteric bud/metanephric diverticulum

Question 15

metanephros begins when the ____ sprouts from the distal end of the _____ at about 5 weeks

Answer 15

ureteric bud/metanephric diverticulum; mesonephric duct

Question 16

formation of the metanephros induces intermediate mesoderm in the sacral region to form a ____ which forms the _____

Answer 16

metanephric blastema which forms the glomeruli and tubules of the nephrons

Question 17

2 components of metanephros

Answer 17

• collecting portion (ureteric bud)

- excretory portion (metanephric blastema)

Question 18

close proximity of blastema to ureteric bud is needed to induce nephron differentiation; if bud is missing or abnormal, kidney will not develop

Answer 18

reciprocal induction

Question 19

collecting portion of metanephros that comes from ureteric bud

Answer 19

• ureter
• renal pelvis
• major and minor calyces

Question 20

excretory portion of metanephros coming from metanephric blastema

Answer 20

• Bowman’s capsule
• proximal convoluted tubule
• Loop of Henle
• distal convoluted tubule

Question 21

ascent of the kidneys involves ____; vascular buds grow toward _____ arteries; happens approximately weeks ____

Answer 21

vasculogenesis; common iliac; 6-9

Question 22

ascent of the kidneys continues until they hit the ____ at about ____ vertebral level

Answer 22

adrenal glands; T11-T12

Question 23

when a kidney does not ascend and remains in the pelvis; can be functional but sometimes are not; has a very short ureter

Answer 23

pelvic kidney

Question 24

when the 2 inferior poles of the kidneys fuse together and get stuck on IMA (L3 level) as they ascend

Answer 24

horseshoe kidney

Question 25

in developing the bladder, the cloaca in the hindgut becomes divided by the ____

Answer 25

urorectal septum

Question 26

urorectal septum divides the cloaca into what 2 portions

Answer 26

ventral urogenital sinus and dorsal anorectal canal

Question 27

superior part of the urogenital sinus that is connected to the allantois and will form the bulk of the bladder

Answer 27

the vesical part

Question 28

middle and inferior portions of the urogenital sinus that will form the urethra

Answer 28

pelvic and phallic parts

Question 29

the distal portions of the mesonephric ducts and the attached ureteric ducts become incorporated into the posterior aspect of the bladder, known as the ____ of the bladder

Answer 29

trigone

Question 30

the mesonephric ducts will become the ____ in males, and the ureteric ducts will become the ____

Answer 30

vas deferens; ureters

Question 31

the mesonephric and ureteric ducts somewhat criss cross with the ____ over top of the ____

Answer 31

mesonephric duct; ureteric duct

Question 32

in females, the ___ and part of the ____ develop from the pelvic part of the urogenital sinus

Answer 32

whole urethra; vagina

Question 33

in males, the ___ and ____ parts of the urethra develop from the pelvic portion of the urogenital sinus, and the ____ comes from the phallic part

Answer 33

prostatic and membranous from pelvis part

spongy urethra from phallic part