Development of the urinary system

Question 1

What germ layer contributes to the development of the kidney?

Answer 1

Mesoderm

Question 2

What part of the mesoderm contributes to the development of the kidney?

Answer 2

Intermediate mesoderm

Question 3

What part of the intermediate mesoderm contributes to the development of the kidney?

Answer 3

Urogenital ridge

Question 4

How many kidney systems form during the development of the urinary system?

Answer 4

Three

Question 5

What are the different kidney systems that form during the development of the urinary system?

Answer 5

Pronephros

Mesonephros

Metanephros

Question 6

Where in the foetus does the pronephros appear?

Answer 6

In the cervical region

Question 7

What is the function of the pronephros?

Answer 7

Has no function itself

Question 8

What is the purpose of the development of the pronephros?

Answer 8

To produce the pronephric duct

Question 9

Where does the pronephric duct extend from and to?

Answer 9

Cervical region

to the cloaca

Question 10

What is the function of the pronephric duct?

Answer 10

Drives the development of the mesonephros

Question 11

Where in the foetus does the mesonephros appear?

Answer 11

Caudal to the pronephros

Question 12

How does the mesonephros develop?

Answer 12

Mesonephric tubules form

together with the mesonephric duct make up the mesonephros

Question 13

What is the function of the mesonephros?

Answer 13

Produces urine

Question 14

What drains the urine from the mesonephros?

Answer 14

Mesonephric duct

Question 15

What does the mesonephric duct drain urine into?

Answer 15

Urogenital sinus

Question 16

What are the other functions of the mesonephric duct, aside from draining urine from the mesonephros?

Answer 16

Ureteric bud sprouts from the mesonephric duct

Role in development of male reproductive system

Question 17

Where in the foetus does the ureteric bud appear?

Answer 17

Caudal to the mesonephros

Question 18

What is the function of the ureteric bud?

Answer 18

Grows and branches
Comes into contact with metanephric blastema
Stimulates the metanephric blastema to differentiate into the metanephros

Question 19

Where is the metanephric blastema located?

Answer 19

Caudal to the mesonephros

Question 20

What is metanephric blastema made up of?

Answer 20

Undifferentiated intermediate mesoderm

Question 21

What part of the metanephros does the ureteric bud form?

Answer 21

Collecting system

• minor calyces
• major calyces
• renal pelvis
• ureter

Question 22

What part of the metanephros does the metanephric blastema form?

Answer 22

Excretory system

-nephrons

Question 23

Where in the foetus does the metanephros appear?

Answer 23

Pelvic area

Question 24

Where does the metanephros migrate to in the foetus?

Answer 24

Posterior abdominal area

Question 25

How does the metanephros migrate from the pelvic area to the posterior abdominal area?

Answer 25

This is mostly due to the lengthening of the trunk of the foetus partly due to true movement of metanephros in caudal to cranial direction

Question 26

What does the metanephros cross over during its migration from the pelvic area to the posterior abdominal area?

Answer 26

Umbilical artery

Question 27

How does the blood supply of the metanephros change as it migrates from the pelvic area to the posterior abdominal area?

Answer 27

Recieves new arterial branches from the aorta as it moves upwards

Question 28

What happens to the old arterial branches from the aorta that supplied the metanephros?

Answer 28

Disappear | occasionally remain

Question 29

What are accessory renal arteries?

Answer 29

Remnants of the old arterial branches from the aorta that supplied the metanephros

Question 30

What is the significance of the blood supply of acessory renal arteries to the kidneys?

Answer 30

They are end arteries | meaning they are the only blood supply to that region of tissue

Question 31

What are some developmental defects caused by abnormal migration of the metanephros?

Answer 31

Pelvic kidney Horseshoe kidney

Question 32

What is a pelvic kidney?

Answer 32

Kidney located in the pelvis instead of the posterior abdominal area

Question 33

What is the cause of a pelvic kidney?

Answer 33

Metanephros failed to migrate upwards | because it got caught on the umbilical artery

Question 34

What is a horseshoe kidney?

Answer 34

Inferior poles of kidneys are fused | fused part is caught under the inferior mesenteric arteries

Question 35

What is the cause of a horseshoe kidney?

Answer 35

Both metanephros move towards the midline to avoid the umbilical arteries during their migration upwards move too close to each other and fuse at their inferior poles fused part gets caught under inferior mesenteric artery during their migration upwards

Question 36

What is renal agenesis?

Answer 36

Kidney failed to develop

Question 37

What is the cause of renal agenesis?

Answer 37

Ureteric bud fails to successfully interact with metanephric blastema

Question 38

What can splitting of the ureteric bud lead to?

Answer 38

Duplication of a ureter Duplication of parts of kidney, or whole kidney

Question 39

What can duplication of a ureter lead to?

Answer 39

Ectopic ureteral orifice

Question 40

What is an ectopic ureteral orifice?

Answer 40

Ureter opens up into an abnormal site, not the urinary bladder as normal

Question 41

What is the main symptom of an ectopic ureteral orifice? Why?

Answer 41

Urinary incontinence | because the sphincters do not control the passage of urine through it

Question 42

What is the first opening of the urinary tract? What drains into this?

Answer 42

Cloaca | the pronephric duct

Question 43

What is the second opening of the urinary tract? What drains into this?

Answer 43

Urogenital sinus | the mesonephric duct

Question 44

How is the urogenital sinus formed?

Answer 44

Urorectal septum divides the cloaca into two compartments | the urogenital sinus is the anterior compartment

Question 45

What happens to the urachus?

Answer 45

Closes up

Question 46

What is the remnant of the urachus?

Answer 46

Median umbilical ligament

Question 47

What does the urogenital sinus develop into?

Answer 47

Superior part develops into the urinary bladder Inferior part develops into the urethra

Question 48

What does the ureter drain into during development?

Answer 48

Initially it drains into the urogenital sinus But as the urinary bladder develops, it drains into the urinary bladder

Question 49

How does the female urethra develop?

Answer 49

From the inferior part of the urogenital sinus

Question 50

How does the male urethra develop?

Answer 50

The mesonephric ducts run through the bladder and prostate gland forming the prostatic urethra The opening of the urogenital sinus is surrounded by genital folds which fuse together to form the spongey urethra

Question 51

What is hypospadias?

Answer 51

Urethra opens at the ventral surface of the penis | rather than at the tip of the head of the penis

Question 52

What is the cause of hypospadias?

Answer 52

Defect in fusion of genital folds

Question 53

What part of the kidney do accessory renal arteries supply?

Answer 53

Inferior part of kidney