Urogenital System

Question 1

urinary shares primordia with what other system?

Answer 1

reproductive

e.g. urethra urine/semen

Question 2

4 primordia contributors

Answer 2

intermediate column of mesoderm aka UR
cloaca aka terminal hindgut
genital swellings
germ cells

Question 3

intermediate column of mesoderm forms what?

Answer 3

gonad/duct system

kidney (nephrons) and part of duct system

Question 4

cloaca forms what?

Answer 4

bladder/portion of urethra

rectum

Question 5

genital swellings form what?

Answer 5

external genitalia

Question 6

where is the IM positioned?

Answer 6

between lateral plate and paraxial

Question 7

urogenital ridges contains two ducts/tubes

Answer 7

mesonephric duct aka Wolffian –> empties into cloaca, forms vas deferens and ureters

paramesonephric aka mullerian –> ends blindly behind cloaca, forms uterus/vagina

Question 8

cloaca

Answer 8

abuts against cloacal membrane (ectoderm)

divides into rectum/bladder

Question 9

genital swellings (form 3)

Answer 9

genital tubercle (penis/clitoris)
labioscrotal folds (labia majora, scrotum)
urogenital folds (labia minora, ventral penis)

Question 10

germ cells

Answer 10

originate in yolk sac and migrate into embryo to developing gonad in urogenital ridge

Question 11

partitioning of cloaca

Answer 11

rectum
bladder
urethra

Question 12

development of metanephric kidney

Answer 12

ureteric bud –> collecting system (ureter, pelvis, calyces, collecting tubules)
metanephros –> nephrons

Question 13

mesonephric duct opens into what?

Answer 13

cloaca

Question 14

formation of metanephric kidney involves which two primordial?

Answer 14

ureteric bud (via mesonephric duct) forms collecting system
metanephros forms nephrons

1. ureteric bud grows into metanephric tissue
2. kidney ascends to adult position

Question 15

ureteric bud separates from mesonephric duct and does what?

Answer 15

incorporates into bladder wall and becomes ureter (superior/posterior opening)

mesonephric duct opening then becomes vas deferens w/ ductus deferens to open into the first part of urethra (prostatic urethra)

FUSION OF ENDODERM w MESODERM (small portion of bladder made of mesoderm)

Question 16

mesodermal component of bladder located?

Answer 16

posterior wall between ureteral openings (TRIGONE)

Question 17

testes vs. kidney blood supply

Answer 17

testes retain original blood supply
kidneys establish new arteries
ductus deferens “loops over” ureter

Question 18

gonads form from what?

Answer 18

medial urogenital ridge

Question 19

indifferent stage

Answer 19

male/female
mesonephric ducts
paramesonephric ducts

Question 20

what persists in the male/female?

Answer 20

male: mesonephric duct
female: paramesonephric

Question 21

variations in kidney ascent

Answer 21

pelvic kidney
horseshoe kidney (abuts INF mesenteric)

Question 22

ureter variation

Answer 22

duplication of the ureter

Question 23

variation of the urorectal septum

Answer 23

incomplete growth: bladder/rectum continuous

Question 24

renal agenesis is a problem with what?

Answer 24

failure of a kidney to develop

problem with uteric bud/metenephros

Question 25

renal artery variations

Answer 25

caudal arteries persist and kidney will have multiple renal arteries

Question 26

polar renal arteries can obstruct what?

Answer 26

enter either lower or upper pole of kidney | can obstruct the ureter

Question 27

urorectal septum location?

Answer 27

between where gut tube empties into cloaca and projection of cloaca into umbilicus (allantois)

Question 28

paramesonephric duct ends blindly where?

Answer 28

between bladder and anorectal canal (where uterus/vagina will eventually form)

Question 29

kidneys begin differentiation where?

Answer 29

in the pelvis

Question 30

final position of kidneys

Answer 30

T11-L2

Question 31

embryonic origin of gonad/duct system? urethra/vestibule? external genitalia?

Answer 31

urogenital ridges cloaca genital swellings

Question 32

cranial end of paramsonephric duct becomes what and opens where?

Answer 32

fimbriated end | opens into peritoneal cavity

Question 33

at what time is embryo phenotypically indifferent?

Answer 33

5-6 weeks | henceforth, genetics influence development

Question 34

primary sex cords are what?

Answer 34

ingrowths of celomic epithelium | germ cells migrate into gonad via these

Question 35

2 stages of gonad development

Answer 35

determination of gonadal sex (testes/ovary): GENETIC | determination of genital sex (repo tract/ext genitalia): HORMONAL

Question 36

male determination

Answer 36

SRY region on Y chrome: sex cords --> seminif tubules (sertoli+leydigs) via germ cells from yolk sac form spermatozoa

Question 37

female determination

Answer 37

something about absence of Y sex cords break down to follicular cells that surround germ cells germ cells form oogonia

Question 38

testosterone mediates differentiation of what?

Answer 38

vas deferens/epididymis

Question 39

DHT mediates differentiation of what?

Answer 39

prostate/seminal vesicles/ext genitalia

Question 40

how does uterus form?

Answer 40

PMN ducts fuse across midline and form UTERUS, UTERINE tubes, part of VAGINA

Question 41

why do mesonephric ducts regress in F?

Answer 41

absence of testosterone

Question 42

why do paraMND differentiate in F?

Answer 42

absence of mullerian inhibiting factor

Question 43

vestiges of gubernaculum in F?

Answer 43

``` ovarian ligament (ovary to uterus) round ligament (uterus to labia major, passes thru inguinal canal) ```

Question 44

sinuvaginal bulbs

Answer 44

endoderm from urogen sinus/bladder grows inwardly to meet fused paraMNDs, then cavitates to form lower vagina

Question 45

vestibule is what?

Answer 45

opening of urethra/vagina, space between labia minora posterior to clitoris

Question 46

in M genital tubercle forms what?

Answer 46

shaft of penis

Question 47

in M endoderm from bladder/urethra forms what?

Answer 47

penile urethra

Question 48

in M urethra folds do what?

Answer 48

fuse across developing ureter at midline

Question 49

labioscrotal folds in M form what?

Answer 49

skin of testes

Question 50

completion of urethra forms from what?

Answer 50

ingrowth of ectoderm from the tip of the glans

Question 51

hypospadias

Answer 51

failure of fusion of urogenital folds

Question 52

PRMNDuct irregularities

Answer 52

bicornuate: 2 ducts don't completely fuse unicornuate: one duct disappeared rudimentary: one side developed more than other

Question 53

nephric vesicles form the?

Answer 53

nephrons

Question 54

what parts of kidney formed by ureteric bud?

Answer 54

collecting tubules, ducts, minor/major calyces, renal pelvis, ureter

Question 55

cells from what grow and form the prostate?

Answer 55

endoderm cells from the proximal urethra

Question 56

renal angenesis results due to

Answer 56

failure of interaction between ureteric bud and metanephros

Question 57

patent urachus

Answer 57

bladder has an opening at the umbilicus | allantois doesn't obliterate to form the median umbilical ligament

Question 58

double ureters/ectopic urethral orifices

Answer 58

URETERIC BUD splits abnormally | abnormal migration of ureter

Question 59

horseshoe kidneys

Answer 59

metanephric tissue may fuse across midline during ascent | gets caught under inferior mesenteric artery