Urogenital system embryology Flashcards Preview

Anatomy II > Urogenital system embryology > Flashcards

Flashcards in Urogenital system embryology Deck (52):
1

Which structure gives rise to the urinary system?

Where does it develop from?

nephrogenic cord

develops from urogenital ridge (intermediate mesoderm)

2

#1 - 5

 

Another name for #4.

Q image thumb

1) liver primordium

2) pronephros

3) nephrogenic cord

4) mesonephric duct (WOLFFIAN)

5) mesonephric tubules

3

#6 - 11

Q image thumb

6) ureteric bud

7) cloaca

8) allantois

9) omphalomesenteric duct

10) mesonephros

11) metanephros

4

#1 - 5

 

Another name for #5.

Q image thumb

1) intraembryonic coelom

2) extraembryonic coelom

3) yolk sac

4) midgut

5) mesonephric duct (WOLFFIAN)

5

#6 - 11

Q image thumb

6) nephrogenic cord

7) urogenital ridge

8) dorsal aorta

9) notochord

10) neural tube

11) dev. spinal ganglion

6

What are the 3 primordial kidney sets? 

Give some brief information.

In which segments of the vertebral column are they located?

 

pronephroi C6 - Th2

  • transitory, non-functional
  • pronephric duct opens into cloaca

mesonephroi Th2 - L3

  • functional, interim kidneys 
  • consist of glomeruli + mesonephric tubules
  • pronephric duct becomes mesonephric duct

metaneprohoi L3 - L5

  • delevop from ureteric bud + metanephrogenic blastema
  • form adult kidneys, ureter

7

How do kidneys/ureters develop?

Acronym?

P M Se B Bl
U T Ne A

  1. Pronephroi + pronephric duct develop 
  2. Mesonephroi develop, take over pronephric duct
  3. urine Secretion starts into amnion as nephrons are developed
  4. ureteric Bud develops from mesonephric duct
  5. metanephrogenic Blastema develops from caudal part of nephrogenic cord
  6. stalk of ureteric bud becomes Ureter
  7. collecting Tubules form from ureteric bud
  8. Nephrons develop from ureteric bud + metanephrogenic blastema
  9. Ascent of kidneys 

8

#1 - 5

 

Another name for #1.

Q image thumb

1) mesonephric duct (WOLFFIAN)

2) stalk of ureteric bud

3) ureteric bud

4) metanephrogenic blastema

5) ureter

 

9

#6 - 10

Q image thumb

6) major calyx

7) renal pelvis

8) minor calyx

9) ureter

10) lobe of kidney

10

#11 - 13

 

What do #11 eventually form?

Q image thumb

11) mesenchymal cell clusters → metanephric vesicles 

12) straight collecting tubule

13) arched collecting tubule

11

#1 - 5

 

Another name for #4.

Which structures are eventually formed by #5?

Q image thumb

1) dorsal aorta

2) urogenital ridge

3) metanephric vesicle

4) mesonephric duct (WOLFFIAN)

5) metanephric tubule → prox./dist. convoluted tubule + loop of HENLE

#4, #5 could also be mesonephric ..., but here we are talking abt the development of
nephrons in the permanent kidney,
 thus metanephros

12

#6 - 10

Q image thumb

6) afferent glomerular vessel

7) glomerulus

8) dev. Bowman's capsule

9) afferent + efferent glomerular vessels

10) primordium of gonad (testis/ovary)

#4, #5 could also be mesonephric ..., but here we are talking abt the development of nephrons in the permanent kidney, thus metanephros

13

What happens to the lobes of the kidney (cf. development of permanent kidney)?

disappear at age 1

14

What is reciprocal induction?

ureteric bud induces development of nephrons from metanephrogenic blatesma

metanephrogenic blatesma induces branching of ureteric bud

15

What is the reason for the ascent of the kidneys?

When does it stop?

What are its consequences?

caudal growth of embryos body → ascent → stops when kidneys come in contact with suprarenal glands

consequences:

  • hilum comes to lie in final position
  • initially supplied by a. iliaca communis
  • finally supplied by aorta pars abdominalis

16

How does the urinary bladder develop?

  1. allantois constricts → urachus
  2. vesical part of urogenital sinus enlarges
  3. mesonephric ducts (ureters) are incorporated as trigonum vesicae

17

What is the remnant of the urachus?

lig. umbilicale medianum

18

#1 - 5

 

Another name for #5.

the yellow indicated ureter should actually be purple since it derives from the Wolffian duct

Q image thumb

1) vesical part of UG sinus

2) pelvic part of UG sinus

3) phallic part of UG sinus

4) urogenital sinus

5) mesonephric duct (WOLFFIAN)

19

#6 - 10

 

the yellow indicated ureter should actually be purple since it derives from the Wolffian duct

Q image thumb

6) ureteric bud

7) urorectal septum

8) cloacal membrane

9) rectum

10) genital tubercle

20

#11 - 15

 

the yellow indicated ureter should actually be purple since it derives from the Wolffian duct

Q image thumb

11) urachus

12) kidney

13) uterine tube

14) ovary

15) vas deferens

21

#16 - 20

 

the yellow indicated ureter should actually be purple since it derives from the Wolffian duct

Q image thumb

16) testis

17) vagina

18) clitoris

19) penis

20) spongy urethra

22

#21 - 23

 

the yellow indicated ureter should actually be purple since it derives from the Wolffian duct

Q image thumb

21) urethra

22) urinary bladder

23) uterus

23

How does the location of the urinary bladder change after birth?

orginally in the abdomen → enters greater pelvis (∽ 6y) → enters lesser pelvis (∽ puberty)

24

Where does the urethra develop from?

Differentiate btw male/female.

  • female: entire epithelium of urethra from urogenital sinus
  • male: epithelium of urethra from urogenital sinus btw urethral folds
    BUT: in glans from surface ectoderm

both: conn. tissue/mm. from surr. splanchnic mesenchyme

explains transition of urothelium to pseudostrat. col. to str. squ. non-ker. (only in males!!) 

25

#1 - 6

 

Where does #1 originate from?

Another name for #5 and #6.

Q image thumb

1) primordial germ cells (originate from dorsal mesentery)

2) gut tube

3) gonadal ridge

4) mesonephric tubule

5) mesonephric duct (WOLFFIAN)

6) paramesonephric duct (MÜLLERIAN)

here #4 could NOT be meta... instead of meso..., because the development of the gonadal ridge is restricted to the region where the mesonephros grows

26

#7 - 12

Q image thumb

7) aorta

8) dorsal mesentery

9) urogenital ridge

10) gonadal cord

11) medulla of gonad

12) cortex of gonad

27

How do indifferent gonads develop?

When do they start to differentiate into testes/ovaries?

What does it mean?

indifferent until end of week 6 = identical in appearance (both sexes)

  1. growing mesonephros produces gonadal ridge in urogenital ridge
  2. gonadal cords grow → cortex/medulla of gonad
  3. primordial germ cells from dorsal mes. migrate + are incorporated into gonadal cords
  4. in week 7: sexual differentiation depends on
    • testis-determining factor TDF → male
    • no TDF → female

28

#1 - 5

 

Another name for #3 and #4.

Q image thumb

1) gut tube

2) mesonephric vesicle

3) mesonephric tube (WOLFFIAN)

4) paramesonephric tube (MÜLLERIAN)

5) primordial germ cells

29

#6 - 10

Q image thumb

6) seminiferous cords

7) mesorchium

8) rete testis

9) septum of testis

10) tunica albuginea

30

List the hormones and cells that are responsible for masculine differentiation (besides TDF).

human chorionic gonadotropin hCG induces 

  • LEYDIG cells → testosterone​⇒ stimulate WOLFFIAN duct to form male genital ducts
  • Sertoli cells → anti-müllerian hormone (AMH)
    ⇒ stimulates MÜLLERIAN ducts to regress

31

How do testes develop?

all events induced by TDF

  1. gonadal cords (now seminiferous cords) pinch off to form rete testis 
  2. tunica albuginea forms
  3. testis seperate from degenerating mesonephros → suspended by mesorchium
  4. seminiferous cords become seminiferous tubules
    • mesenchyme btw tubules →  Leydig cells
    • seminiferous tubules → Sertoli cells  
  5. surface epithelium of testes flattens → tunica vaginalis testis
  6. rete testis and mesonephric tubules fuse → efferent ductules

32

#1 - 6

 

Another name for #5.

Q image thumb

1) gut tube

2) cortical cords

3) former gonadal cords

4) rete ovarii

5) paramesonephric duct (MÜLLERIAN)

6) mesovarium

33

#7 - 12

 

Another name for #9 and #12.

Q image thumb

7) surface epithelium

8) prim. germ cells

9) mesonephric duct (WOLFFIAN) + vesicle

10) degenerating rete ovarii

11) uterine tube

12) prim. ovarian follicles (= oogonia)

34

How do the ovaries develop?

all events induced by absence of TDF

  1. ovary seperate degenerating mesonephros → suspended by mesovarium
  2. gonadal cords seperate → rete ovarii
  3. cortical cords form from mesothelium of peritoneum
  4. primordial germ cells incorporated into cortical cords
  5. cortical cords containing a germ cell break up → form primordial follicle (= oogonium) → active mitosis of oogonia → become primary oocytes after birth
  6. surface epithelium flattens → forms tunica albuginea that seperates follicles from cortex

35

Where do the MÜLLERIAN ducts develop from?

Which transitional structures are formed by them in females?

develop from mesothelium lateral to mesonephroi 
open from peritoneal cavity into future pelvic region

in females: fuse caudally → form uterovaginal primordium 
→ produces sinus tubercle on urogenital sinus

36

How do epididymis and its accompanied structures develop?

  • distal end of Wolffian duct
    • appendix edididymis
    • convolutes → epididymis
    • vas deferens when invested w/ sm. m.
    • ductus ejaculatorius
  • mesonephric tubules (originally from metan. blastema)
    • efferent tubules
    • paradidymis

37

Where does the uterus develop from?

uterovaginal primordium + surr. splanchnic mesenchyme (→ endometrial stroma + myometrium)

38

Which structures form lig. latum?

Which other structures are formed during that proc.?

 

fusion of MÜLLERIAN ducts 

→ lig. latum + mesenchyme proliferates → parametrium

39

Where do accessory sex glands in males and females develop from?

mostly derived from endoderm of UG sinus at parts of urethra

male:

  • prost. part of urethra  → prostate
  • spongy part of urethra → Cowper gll.
  • BUT: Wolffian duct → gl. vesiculosa

females:

  • urethral + paraurethral gll.
  • maj. vestibular gll.

 

40

How does the vagina develop?

  1. sinus tubercle forms laterally sinovaginal bulbs
  2. sinovaginal bulbs fuse → vaginal plate
  3. central parts break down → lumen

→ hymen develops as only remnant of sinus tubercle

41

Describe the indifferent part of the development of external genetalia.

mesenchyme produces genital tubercle

 → labioscrotal folds (lateral)  
 → urethral folds (medial), surround UG sinus

 

42

How do the male external genetalia develop?

  1. as genital tubercle elongates → phallus
  2. urethral folds approach each other → spongy urethra 
  3. at glans penis ectodermal ingrowth meets spongy urethra → external urethral orifice formed
  4. ectoderm around glans → preputium
  5. corpora cav./spong. formed by mesenchyme
  6. labioscrotal folds fuse → scrotum + raphe scroti

43

How do the female external genetalia develop?

  1. instead of phallus clitoris formed from genital tubercle
  2. urethral folds
    • fuse posteriorly → frenulum of labia majora
    • unfused → labia minora
  3. labioscrotal folds
    • fuse post./ant. → labial commissurae + mons pubis
    • unfused → labia majora

 

44

What is the gubernaculum, what does it do and what are its derivatives?

outgrowth from caudal pole of gonad into labioscrotal folds

→ forms path for processus vaginalis → inguinal canal

derivatives:

  • in males: gubernaculum testis
  • in females: lig. ovarii prop., lig. teres uteri
     

45

What are the deep and superficial inguinal ring?

openings produced by gubernaculum

  • deep: in transversalis fascia 
  • superficial: in external oblique aponeurosis

46

What are causes and consequences of the descent of the testes?

causes:

  • growing pelvis + deg. mesonephroi 
  • increased intraabdominal pressure due to growing abd. viscera

consequences:

  • ureter crossing w/ ductus deferens
  • course of test. vessels
  • coats of testes 

 

47

In what way does the descent of the ovaries differ from that of testes?

do not pass from pelvis to enter inguinal canal

​proc. vaginalis disappears, BUT sometimes persistent as canal of NUCK

48

What are the derivatives of the Wolffian duct in males?

  • appendix + duct of epididymis
  • ductus deferens
  • ejaculatory duct + seminal gland

in both:

  • ureter + trigonum vesicae

  • renal pelvis, calices + collecting tubules

49

What are the derivatives of the Wolffian duct in females?

  • appendix vesiculosa
  • duct of epophoron
  • longitudinal duct; Gartner duct

in both:

  • ureter + trigonum vesicae
  • renal pelvis, calices + collecting tubules

50

What are the derivatives of the Müllerian duct in males?

  • appendix of testis

51

What are the derivatives of the Müllerian duct in females?

  • hydatid of Morgangni (= paratubal cyst at infundibulum of uterine tube)
  • uterine tube
  • uterus

52

What are the derivatives of the mesonephric tubules in males/females?

male:

  • efferent ductules of testis
  • paradidymis

female:

  • epoophoron (like paraophoron, but more cranial)
  • paraophoron (btw ovary + uterus)