Development of the Urinary System

Question 1

What is the primordia of the lung?

Answer 1

intermediate column and splanchnopleure of the hindgut

Question 2

intermediate column develops a ______ along its length consisting of a medial _____ and lateral _____

Answer 2

urogenital ridge

gonadal ridge

nephrogenic cord

Question 3

What are the series of three embryonic kidneys?

Answer 3

pronephros

mesonephros

metanephros (functioning kidney)

Question 4

mesonephric duct (wolffian duct)

Answer 4

a structure in the UG ridge that connects mesonephric tubules in the nephrogenic cord with the hindgut cloaca

it is the embryonic ureter

Question 5

Where do permanent kidneys develop from?

Answer 5

mesodermal ureteric bud off the mesonephric duct near the cloaca

invades the metanephric mass of the intermediate mesoderm (nephrogenic cord)

Question 6

significant events in early kidney development

Answer 6

intermediate column develops a urogenital ridge

primary germ cells migrate from the gut tube into the gonadal ridge

nephrogenic cord forms

mesonephric duct connects mesonephric tubules in the nephrogenic cord with the hindgut cloaca

permanent kidneys develop from the mesodermal uteric bud, which invades the metaneprhic mass

Question 7

significant events of later development of the kidneys

Answer 7

developing kidney migrates from pelvis to posterior abdominal wall

cloaca expands and divides into two parts, rectum and urogenital sinus

cloaca becomes the UG and anal membranes

paramesonephric (mullerian) ducts invaginate on the lateral surface of each UG ridge and fuse in the midline

a small genital tibercle develops

Question 8

pelvic kidney

Answer 8

when the kidneys fail to ascend

Question 9

horseshoe kidney

Answer 9

when the inferior poles of the kidneys fuse in the pelvis

during ascent, they hook around the inferior mesenteric artery off the aorta as a horseshoe kidney

Question 10

What does the cloaca divide into?

Answer 10

rectum and urogenital sinus

Question 11

exstrophy of the bladder

Answer 11

an inferior abdominal wall defect resulting from improper folding of the gastrula during the fourth week

a think UG membrane may rupture, and the mucosa of the posterior bladder wall protrudes through the defect

Question 12

paramesonephric (mullerian) ducts

Answer 12

ducts that invaginate into the lateral surface of each UG ridge and fuse in the midline

Question 13

significant events of the indifferent stage

Answer 13

8 weeks

all embryos have a single, common set of UG structures:

metanephros

mesonephros

gonads attached medially to the mesonephros (from the genital ridges)

mesonephric (wolffian ducts)

paramesonephric (mullerian) ducts

UG sinus

genital tubercle (phallus)

labioscrotal folds

Question 14

metanephric diverticulum (ureteric bud)

Answer 14

originates from the mesonephric duct, but soon makes its own connection to the cloaca

gives rise to ureters, renal pelvis, calyces, and collecting ducts and tubules in the pyramids

Question 15

significant events after 8 weeks of development

Answer 15

kidneys ascend and the bladder develops from the UG sinus above the entrance of the mesonephric and paramesonephric ducts

lower part of the UG sinus develops into the urethra and related glands in both sexes

the allantois degenerates to form the urachus, a permanent fibrous cord

the ductules of the testis and the mesonephric duct will become the ductus deferens and epididymis

Question 16

mesonephric mesoderm

Answer 16

gives rise to kidney nephrons

Question 17

congenital anomalies involveing the urachus

Answer 17

lumen may persist as urachal cysts

sinuses (blind pouches) can extend from the navel and/or bladder

Question 18

multiple reanal arteries

Answer 18

persistence of new arteries that connect with the metanephric kidneys as they ascend

Question 19

hydronephrosis

Answer 19

a lower renal artery supplying the inferior pole of the kidney may compress the ureter that causes urinary distension of the renal pelvis and calyces

Question 20

abnormal divisions of the ureteric bud

Answer 20

can form a double renal pelvis or ureter

if the metanephric mesoderm is involved, there iwll be a double kidney on one side

Question 21

How does renal agenesis occur?

Answer 21

if the ureteric bud does not engage the metanephric mesoderm

Question 22

oligohydraminos

Answer 22

too little amniotic fluid

indicates renal agenesis