Embryology summary

1. Embriology CMU M44 Zack.lim
Primordial follicle
1)primary oocyte 1st mitosis
2)follicular epithelial cells
- Primary follicle Secondary follicle
2nd mitosis
1st mitosis
metaphase
1) follicle a)2ndary oocyte mitosis a)zygote
b)1st polar body b)2nd polar body
2) antrum
epididymis -storage of sperm
vas deference-
Seminal vesical - semen,MIF(mullerian inhibitory factor)
efferent duct-
3 Clinical age : Naegele’s rules :
LMP = 280d -3 +7
Post-ovulatory age :
1d 14d 28d Oocyte <24hr
|------( -2d ][ +1d)-----14 -----------------| Sperm <48hr
ovulation
1wk blastogenesis corona radiate ~ zona pellucida +
(1~14d)
2nd mitosis female pronucleus
male pronucleus( )
+ zygote
2wks
30hr Zygoe 248
3~7d Morula
4~5d Blastocyst
germinal
6~7d
blastocyst --- blastocele
— trophoblast
Inner cell mass cyto-tropho-blast Syn-cytio-tropho-blast
1.
2wk 11~12d
- Uteroplacental circulation
???
embryonic cell-
/
Extra-embryonic mesoderm
Epiblast hypoblast
Secondar
= =
y/definiti
~somatic~
ve yolk
Extra-embryonic
amniotic cavity Primary yolk sac
sac
Splanchnic
+ trophoblast chorion
mesoderm

2. 3wk 13~14
3 primitive streak
? notochord formation
18d neurulation
20d somites
&
- / 2
-
3.
2
1.
1. 1. 3
neural groove
2. 2.
.
fold
3. 3.
3
4th wks>
>
Neural crest cell>PNS,
Neural canal
Neural Tube
>
>
neurenteric canal:
If
>
)
:
>
somite43
(CN12
If
Sacro-coccygeal teratoma
&
>
,
+
( amniotic cavity)
>
adrenal(
>CNS (
>
31
,
(
( yolk sac )
)
,
,
etc
)
)
15~56d (3~8wks)
Extra: 1.
precordal plate oropharyngeal paraxial mesoderm
2.
membrane
Intermediate mesoderm
3.
Lat
embryonic
4~8 4~5wk 1. pharyngeal arch = brachial arch
by + +
2. pouch by ( primordial pharynx
)
3. groove by
2.
22d -
4wk -critical period 4~8wks
* -22~23d , 4wks color doppler
24d –
4wk -- thyroid deverticulum
ectoderm mesoderm endoderm
**thymus, adrenal
-
tube canal Surface~
@
CNS PNS CV,
, Eg
# : &
&
./ arch
-factor 2,7,9,10
Extra: vit K
Parasympathetic-CN 3,7,9,10 lig
.n
CN5,7,9,
10
1st M - , , ( )
3 ,V .a
-
I ,
.a
2nd S -
,VII .a , ,
, ( )
rd
57~266d (9~38wks)
3 IX .a
.a
4th X IV: .a
VI: .a
5th
6th ,X
:
groove 4 pouch
Fetal
1st 1st
2nd
2~4 tonsil
3rd , thymus
4th
3.
CV
: cephalic folding
( )
heart tube
Truncus arteriosus
bulbus cordis : conus artriosus
: aortic vestibule

3. ventricle
primordial Atrium -
-
sinus venosus R’t horn ( ), coronary sinus
L’t horn ( ), sinus venarum
th
Partition: 4~7 wks
AV valve
A-V canal Endocardial cushion
atrium ( :R’t to L’t shunt )
Septum premium ostium primum ostium secundum
( )
Septum secundum foramen ovale
@ foramen ovale valve
ventricle
Primodial interventricular septum muscular part of
endocardial cushion membranous part of interventricular septum
1. : : portal vein, hepatic sinusoids, hepatic vein
vitelline vein yolk sac
2. :
Umbilical vein : O2 or ICV
3.
1. a). .a dorsal intersegmental.a
b). .a vitelline artery
c). .a Umbilical .a
2. Aortic arch: 6
1st .a ext.carotid.a
.a maxillary.a
2nd .a stapedial .a
O1 -ostium premium
3rd .a
S1 -septum primium
.a
S2 -septum secundum
4th
FO -foramen ovale : .a
:
5th
6th :
,
3. dorsal intersegmental .a X30
4. vitelline .a
5. .a Umbilical .a
: 4wks , , ,
primodial gut :
- orapharyngeal membrane - by. a.
b. primordial mouth
- cloacal membrane - by .a.
b. anal pit
foregut midgut hindgut
1.primordial pharynx & 12 ( ) 2/3 1/3 , ,
( ,,, , ,
U , = :
)
Yalk stalk vitelline duct
2.
a. Cranial limbs: ,
3. , ,12 ( )
b. caudal limbs: ,
3. , ,
90 , SMA A. -
6wks-
180 Cloaca uro-rectal septum
10wks-
270
: / , , (
), urogenital sinus ( ),
( )
180 ,
( ) B. -- hindgut
, Cloacal membrane
@ 7wks A + B pineal body
()
-
@ from
Uro-genital membrane
~
- , 8wk
Anal membrane
If >
( ) :
a. umbilicoileal fistula
b.Meckel
c. umbilical sinus

4. > primordial pharynx> & -
laryngotracheal diverticulum> -
> laryngotracheal tube >
bronchial bud
Bronchial bud 4w 4w
5w
5w~
1
pseudogland
pronephros
ular period terminal
meta meso
bronchiole
nephros nephros
16w
2. ~
=
~
Canalicular Repiratory~-
Muellerian duct Wolffian duct
period
=para-
alveolar duct mesonephrons
3. 24 Xby SYY gene by SYYgene
Terminal sac alveolar sac
, : : , ,
~ - BBB
-appendix testis
,
- surfactant -utriculus prostatus
: ,
32~
4. .n
:
8w
alveolar @95% -appendix vesiculosa
-epoophoron
-Gart her’s duct
Urogenital sinus Prostate?,Urinary bladder , Urethra lower vaginal
* vaginal : Prostatic utricle ( 2/3)
1/3-para-mesonephric
2/3-urogenital sinus bulbo-urethral gl Greater vestibular gl
Genital tubercle/ #Phallus Glans penis Clitoris
Corpus spongiosum Bulb of vestibule
Corpus cavernosa Corpus cavernosa
Urogenital/urethral fold penis(Ventral aspect) Labia minora
Genital/labioscrotal swelling scrotum Labia majora
Cortex of medulla Rete ovarii
Rete testis
Gubemaculum testis Ovary lig, Round lig
gubermaculum
Mesonephric tubules epoophoron
Ductuli efferentes
Mesonephric duct Duct of epoophoron
Duct of Gartner
Para-mesonephric Appendix of testis fallopian tube
uterus
Median umbilical fold .a lig X2
*indomethacin
Median umbilical cord/Urachus
X
Medial umbilical fold Round lig.
Obliterated umbilical.a. .a .v
PGI2
Lat Inf. Epigastric. Vessels Ductus venous Venous lig
Retro-uterine Recto-uterine pouch of Douglas Ductus arteriosus lig ( for recurrent largyngeal.n)
PGI2
Bradykinin
Foramen ovale
Umbilical cord :1.2 ( )
2.1 (
3. Urachus- - alantosis( -
)
Placenta :1. hCG, hGS,relaxin,estrogen,progesterone
( 8wk HCG,10wk estrogen,progesterone)
: 1. decidua basalis
2. chorion frondosum

5. 1.decidua parietalis
2. capsularis
3. basalis
nd
2 wks Primary chorionic villi
Chrionic villi cytotrophoblastic core
3rd wks Secondary mesenchyme
Tertiary
& :
1.Placenta membrane:1.syncytiotrophoblast
2.cytotrophoblast *cytotrophoblastic shell
3.connective tissue of villus
4.endothelium of fetal capillus
hermaphroditism=intersexuality: &
70% 46XX & or :
20% 46XX/46 XY(mosaic)
10% 46XY
46XX &
Congenital adrenal hyperplasia
46XY & 1. T & MIF
2. =
Testicular ferminization syn = androgen
insensitivity syndrome(AIS)
Trisomy 21 Down syndrome Growth retardation, mental retardation,
craniofacial abnormalities
Trisomy 18 Mental retardation, ,
low set ears, flexion of fingers and hand
Trisomy 13 Mental retardation, ,
Cleft lip&palate, deafness, eye defect, polydactyly
XXY Klinefelter syndrome ,sterility,testicular atrophy,gyncomastia
Extra: X:mental retardation
45X Turner syndrome ovaries(gonadal dysgenesis),
XXX Triple X syndrome Scanty menses, mental retardation