Embryology

Question 1

Kidney embryology:

Pronephros

Answer 1

Week 4, then degenerate

Question 2

Kidney embryology:

Mesonephros

Answer 2

Function s interim kidney for 1st trimester;

Later contributes to male genital system

Question 3

Kidney embryology:

Metanephros

Answer 3

Permanent,
first appear in 5th week of gestation;
continues on with development

Kidney made of two components:
Ureteric bud
Metanephric mesenchyme

Question 4

Fetal kidney:

ureteric bud

Answer 4

Derived from caudal end of mesopnehros;
Finally calanized by 10th week

ureter,
pelvises,
calyces,
collecting duct

Question 5

Fetal kidney:

Metanephric mesenchyme

Answer 5

Ureteric bud interacts with this tissue;

interaction induces differentiation and formation of glomerulus through distal convoluted tubule

Question 6

Ureteropelvic junction

Answer 6

Last to canalize

Most common site of obstruction (hydronephrosis)

Question 7

Potter’s syndrome

Answer 7

Oligohydraminos
compression of fetus
limb deformities
facial deformities, and 
pulm hypoplasia

Causes: ARPKD, posterior urethral valve, bilateral renal agenesis

“Babies who cannot Pee in utero develop Potter’s”

Question 8

Horseshoe kidney

Answer 8

Inferior pole of both kidneys fuse.
Trapped under IMA
and remains low in the abdomen

Associated with Turner’s

Question 9

Multicystic dysplastic kidney

Answer 9

Cause: Abnormal interaction between ureteric bud and metanephric mesenchyme.

Result: nonfunctional kidney consisting of cysts and connective tissue.

Consequence: if unilateral (most common), generally asymptomatic with contralateral hypertrophy.

Often diagnosed prenatally via US

Question 10

Ureters course

Answer 10

Ureters pass under

1) uterine artery
2) ductus deferens (retroperitoneal)

“Water under the bridge”