GU Embryology

Question 1

kidenys, ureters, bladder form from which layer?

Answer 1

intermediate mesoderm

Question 2

3 stages of the kidney

Which is the adult kidney derived from?

Answer 2

1) pronephros
2) mesonephros
3) metanephros

Adult kidney is derived from metanephros

Question 3

excretory unit forms form _____

Answer 3

mesonephric tubules

Mesonephric tubules form Bowman’s capsule, glomerulus, renal corpuscle.

Question 4

mesonephroi (function, time functional, regression)

Answer 4

Produce small amounts of urine.
6th-12th weeks.

Regress in FEMALEs, persist in males as genital duct system

Question 5

ureteric bud

Answer 5

Branched from caudal end of mesonephric duct.

Forms collecting system of kidney (collecting ducts, calyces, ureter)

Question 6

two structures that form the kidney

Answer 6

ureteric bud

metanephric blastema

Question 7

metanephric blastema

Answer 7

Forms the rest of the kidney that the ureteric bud does not form.

Ureteric bud penetrates metanephric blastema and bifurcates

Question 8

cloacal region is divided by _________________ into a ventral _________ and a dorsal ___________

Answer 8

cloacal region is divided by urogenital septum into a ventral urogenital sinus and a dorsal anorectal canal

Question 9

ascent of kidneys

Answer 9

Form in sacral area.
Ascend to lumbar region by differential growth of the body.

Revascularized. If original vessels do not regress, then accessory renal arteries are present.

Question 10

horseshoe kidney

Answer 10

Inferior poles of two mesonephroi fuse during ascent of kidneys.
Cannot migrate further up than the origin of the IMA

Question 11

pelvic kidney

Answer 11

Failure of migration of one/both kidneys.
Kidney is retained in the pelvis.
No adverse effect on kidney function

Question 12

renal agenesis

Answer 12

Kidney fails to develop.
Due to faulty tissue-tissue interactions between ureteric bud and nephrogenic mesenchyme

bilateral can be fatal (potter syndrome)

Question 13

potter syndrome

Answer 13

Bilateral renal agenesis.
Oligohydramnios compresses fetus.
Stillborn or die soon after birth.

(amniotic fluid is largely made from fetal urination )

Question 14

duplication of ureter

Answer 14

Variable in length.

Occurs if initial branching of ureteric bud is not incorporated into developing kidneys.

Question 15

urachal cyst

Answer 15

Small patent area of the urachus.

Only detected if it becomes infected.

Question 16

urachal sinus

Answer 16

Lumen in superior portion of urachus remains patent.
Opens at urachus.
Fluid is from endothelial lining, not urine

Question 17

urachal fistula

Answer 17

Rare.
Entire urachus remains patent.
Allows urine to exit from urachal orifice.

Question 18

SRY (what it encodes, what that does)

Answer 18

SRY = Sex-determining region of the Y chromosome.
Encodes TDF (testes-determining factor).

SRY directs differentiation of Sertoli cells (directs male development).

In ABSENCE of SRY/TDF, female development occurs.

Question 19

absence of testosterone on mesonephric ducts, paramesonephric ducts

Answer 19

Mesonephric ducts degenerate.

Paramesonephric ducts give rise to female reproductive system.

Question 20

presence of testosterone on mesonephric ducts, paramesonephric ducts

Answer 20

Mesonephric ducts remain.

Paramesonephric ducts degenerate.

Question 21

paramesonephric ducts develop into (male and female)

Answer 21

FEMALE:
Uterine tubes, uterus, cervix, superior 2/3 of vagina, Hydatid of Morgagni

MALE:
appendix testes

Question 22

mesonephric ducts develop into (male/female)

Answer 22

FEMALE:
appendix vesiculosa, Gartner’s duct

MALE:
epididymus, ductus deferens, seminal vesicles, ejaculatory duct

Question 23

mesonephric tubules develop into (adult male/female)

Answer 23

FEMALE:
epoophoron, paraoophoron

MALE:
efferent ductules, paradidymus

Question 24

phallus develops into (adult male/female)

Answer 24

FEMALE:
clitoris

MALE:
glans and body of penis

Question 25

urogenital folds develop into (adult male/female)

Answer 25

FEMALE: labia minora

MALE: penile raphe

Question 26

labioscrotal folds develop into (adult male/female)

Answer 26

FEMALE: labia majora, mons pubis

MALE: scrotum, scrotal raphe

Question 27

gubernaculum develops into (adult male/female)

Answer 27

FEMALE: ovarian ligament

MALE: gubernaculum testes

Question 28

didelphic uterus

Answer 28

Paramesonephric ducts fuse to urogenital sinus separately.

2 vaginas, connected to own uterus separately

Question 29

unicornate uterus

Answer 29

One entire Mullerian duct regresses or fails to elongate.

Question 30

hypospadias

Answer 30

Urethra opens onto VENTRAL (underside) surface of penis.

Failure of urogenital folds to fuse normally

Question 31

epispadias

Answer 31

Urethra opens on DORSAL side of penis.

Failure of urogenital folds to fuse normally

Question 32

testicular hydrocele

Answer 32

Lumen between tunica vaginalis and peritoneal cavity fills with serous secretions.

Question 33

cryptorchidism

Answer 33

Undescended testes.

Question 34

male pseudohermaphroditism

Answer 34

Genetic males with feminized genitals.

Androgen insensitivity syndrome (androgens do not work on target cells).
5-alpha reductase deficiency (cannot make dihydrotestosterone).

Question 35

female psuedohermaphroditism

Answer 35

Genetic females with masulinized genitals.

Disorder of adrenal glands that cause excessive production of androgens.

Question 36

klinefelter syndrome

Answer 36

Extra X chromosome in males (XXY).
Failure of Leydig cells to produce sufficient amounts of male steroids.
Small testes, azoospermia/oliogospermia.
Gynecomastia, eunuchoidism

Question 37

turner syndrome

Answer 37

45X or 46XX/45X mosaicism.
Failure of normal sexual maturation at puberty, short stature, webbed neck, coarctation of aorta, cervical lymphatic cysts