04-EMBRYOLOGY

meiosis(PMAT) Prophase(longest)-leptotene, zygotene, pachytene, diplotene, diakinesis Metaphase Anaphase Telophase

oogenesis→ primitive germcell(epiblast)

→ yolk sac(w3)→ genital ridge(w6)

→ oogonia(w9)→ prim oocyte(2n)(w12)

→ primord follicl(2n) format begin(w14)→ w20=7mill

→ primordial follicl format compl(w24) (birth=2mill), finish prophase of 1st meiotic division, remain in resting

→phase(dictyotene> diplotene stage) meiosis1 resume at puberty 36h before ovulation(LH surge)(4lac)

→ sec oocyte(n) form just(3-4h) before ovulation(arrest in metaphase) secondary oocyte complet 2nd meiotic division after fertilization 1st stage maturation of ovarian follicle before ovulation final stage maturation after fertilization 1000oocyte atresia/mth fertilizable life span=24h

spermatogenesis(74d) FSH+ testosterone> FSH> testosterone begin at puberty

→ spermatogon(primit germ cell)(2n×1)→ mitosis

→ prim spermatocyte(2n×16)→ meiosis1

→ sec spermatocyte(n×32)→ meiosis2

→ spermatid(n×64)→ epididymis(caudate)

→ maturity&motility(12-14d)

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→ spermiogenesis(n×64) Capacitation begin-Cx, max-FT(7h) time to reach FT=30min cx reservoir=72h fertilizable life span=72h

zona Pellucida(acell memb,Glycoprot) separat ovum fr Granulosa cell(Gap jn), prevent Polyspermia zona rxn-release Cortic granule(Ca) zygote present in FT=3d phySiol sphinct-iSthmus FT aNat sphinct-iNterstit FT

→ fertilisation in ampulla FT→ zygote→ cleavage

→ 8cell stage enter uterine cavity→ morula(16cell)

→ zona pellucida disappear→ fluid fr uterus enter morula

blastula=ouTer cell mass(Trophoblast)+ inner cell mass(embryoblast)+ →cavity(blastocyst)

→ some cell of inner cell mass differentiat to form endoderm trophoblast=Syncytotrophoblast(cell wall abs, nucl Scatter)+ Cytotrophoblast(Cell wall present, 1nucl/cell),

→ embryoblast= epiblast(tall columnar cell)+ hypoblast(cuboidal cell)→ epIblast enclos amnIot cavit, hYpoblast enclose Yolk sac

hypoblast form extraembyonic mesoderm which lies b/n amniotic cavit& →cytotrophoblast, yolk sac& cytotrophoblast

small cavities appear in extraembryonic mesoderm join to form extraembryonic →coelom(chorionic cavity)

extraembryonic mesoderm split into somaTopleuric extraembryonic mesoderm(lining Trophoblast)+ splanchnopleuric extraembryonic mesoderm(lining

→yolk sac) hypoblast at 1end become columnar to form procordal plate/buccopharyngeal

→memb(future mouth) epiblast at caudal end form elevation (primitive streak), round end(primitive

→knot/node), depression(blastopore/primitive pit) intraembryonic mesoderm split into 3part paraxial-somite(dermatom, sclerotom) intermediaTe-urinary& geniTal system lat plate enclos cavity-intraembryonic coelom(pleural, pericardial, periton cavit)

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→ →germ layer format-endo meso ecto endoderm-lung, int ear, med layer TM, thy gld, GIT, UB epith mesoderm-heart, spleen, adr cortex, middl layer TM, kidn, ureter, UB, UB trigon epith, glomus tm, Wharton jelly ectoderm-ext ear, lat layer TM, CNS neuroectoderm-Schwann cell

neural crest-adren medull, leptmening, odontoblast, melanocyte, dorsal root ganglion, sympath ganglion, parafollicular/C/clear/light cell thy, Merkel cell, larynx cartil(thy, cricoid, arytenoid)

trophoblast memb-chorion, amnio, yolksac, allantois

embryo=3w-8w(PF)fetus>8w(PF)

FETUS concept(8cell) reach uter cavit-d4(3-4) morula(16cell)-d4 blastocyst-d5 zona pellucida lost-d5 interstitial implantation begin-d6(6-7) differentiation of trophoblast into cyto& syncyto-d8 lacunae appear in syncytium-d9 implantat complet(post uterin wall, mid sagittal plane)-d10 primary villi-d13 secondary villi-d16 CNS developm start-w3 notochord form fr epiblast-w3 neural plate form(thicken of ectoderm)-d16 indent in midline(neural groove) with enlarge on either side(neural fold)-d18 3germ layer form-d21 tertiary villi-d21(w3) fetoplacental circulation-d21(w4) first heart beat-d21 fusion of neural fold(to form cerebral hemisph) begin-d22 open end close to form rostral neuropore-d24 caudal neuropore-d27 devel of larynx start-w4 pronephros disapp completely-w4 complete closure neural tube-d30 metanephros(perm kidney) start developm-w5 1st bone to ossify-clavicle-w5

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genital ridge app-w5 Mullerian(paramesoneph duct) app-w6 genital tubercle app-w6 ear developm start-w6 complete ventricular struct-d46 anal opening form-w7 testis-w7 Muller inh Sub(chr19) secret by Sertoli cell prevent Mull duct develop(i/l)-w7 gross body movem on USG-w7 fetal ACTH-w7 fetal glucagon-w8 testosterone synth begin(hCG)-w8 ovary-w8 lymphoid ts fr yolk sac, fetal liver, bone marrow reach thymus-w8 appendix app-w8 Muller duct disapp mal-w8-9(9) fetal swallow amniot fluid-w10 GH,prolactin prod by fetal pituit-w10 resolution of physiol umbilic herni-w10 FHS on doppler-w10 inter genit differentiat to mal/fem-w10 uterus form-w10 end diastol flow seen in fet a-w10 fetal thyroxin-w10-12 breathing movem app-w11 FSH, LH, ADH, oxytocin by fetal pituit-w12 fetal insulin-w12 urine production-w12 external genitalia form-w12 bil in amn fluid-w12 1st placental remodelling-w12 fingerprint develop-w12-16 larynx develop-m3 decidua caps& pariet fuse(vera form)-w14-16 formation of discrete placenta-w16 matern IgG cross placenta-w16 lanugo app-w16 nail app-w16 meconium app-w16 all gen of bronchus fully present-w16 placenta wt=fetal wt-w17 cavity in internal genitalia-w18-20 FHS heard by stethoscope-w18-20

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seb gld app-w20 surfactant synth begin-w20 inf turbinat ossifie-w20 ear developm complete-w20 pinna adult config-w20 primitive alveoli form-w24 fetal sucking movement-w24 hearing-w24 sweat gld app-w24 testis at deep inguinal ring-w24-28 demand of iron by fetus evident-w25 surf app in amnion-w28 alveoli expand-w28 light perception-w28 sex can be differentiated by ext genitalia-w28 testis descent to scrotum-end mth9

Hematopoiesis→ mesoblasti-yolk sac-10-14d 10-12w→ hepatic-liver, LN, spleen-6-8w throughout gestation

→ myeloid-bonemarrow-m5 throughout life→ switchover fr HbF HbA begin-36w, completed-6mth PP

Hb Gower1(ζ2,ε2)-3-4w Gower2(α2,ε2)-4-13w Portland(ζ2,γ2)-4-13w HbF(α2,γ2) HbA(α2,β2) HbA2(α2,δ2) HbF at bth=75-80% 1st app in early normoblast reduce Hb absorb wavelth=660nm

fetal struct—TVS(5-7MHz,empty UB)— TAS(3.5MHz,full UB) gest sac(true-eccent,pseudo-centr,5- 10mm)—4w1-3d(30d fr LMP,15d PF)—5w yolk sac—5w—6-7w cardiac activity—5>5-6w—6>6-7w

critical titre gest sac on USG-hCG(IU/l) TVS-1500(lowest-1000) TAS-6500

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POG(w)-fetal wt(g) Hadlock formula-birth wt=BPD+AC+FL 20-300 24-600 28-1100 period of viability=w24

gest age assessm crownrump lth(CRL)-7-10w(1st,all trim) BPD(thalamus& cavum sept pellucidum)-16w(2nd trim) fem lth-3rd trim AC(true transv view at level of umbilic v entering liver)-macrosomia, IUGR, all trimest

RBC=5-6mill/mm³Hb=16.5-18.5g%retic=5%erythroblast=10%WBC=15000-20000/mm³RBC life=90dnear term urine prod=650ml/d=27ml/hCO=350ml/kg/minbld vol=125ml/kgpress for 1st chest expansio=25cmH2O

cranial aspect of ectodermal cloacal fossa-external genitalia genital fold-labia minora-ventra aspect penis genital fold ectoderm-ext vag orifice genital Ridge-ovaRy-testis genital Swelling-labia majora-Scrotum genital Tubercle-cliToris-glans penis prox gubernaculum-ovarian lig dist gubernaculum-round lig

⅔ Mullerian(paramesonephric) duct-up vag,cx,uterus,FT-appendix of testis/utriculus masculinus/hydatid Morgagni, prostat utricle

⅔ mesoderm of 2fuse Mullerian duct-up vagina⅓ endoderm sinovag bulb> urogenit sinus -lower vagina

urogenital sinus-vestibule Wolffian/mesonephr duct-hydatid of Morgagni,Gartner duct, paraoophoron, epoophoron-intern genital, vas deferens, ejaculat duct, epididymis, seminal vesicle

appendix testis-cranial end paramesonephric(Mullerian) duct appendix epididymis-cranial end Wolffian(mesonephric) duct

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kidney develop fr mesodermal ridge along post wall of abd cavity, retroperiton excretory unit(nephron-glomerul, PCT, Henleloop, DCT)-metanephros(blastema,

←metanephric mesoderm) intermed mesoderm collecting duct, pelvis, ureter-ureteric bud(mesonephric duct)

hindgut preallantoic-GI hindgut postallantoic(endodermal cloaca) primitive urogenital sinus-urethra, UB

primitive rectum-lower rectum, up anal canal cloacal memb-pectinate/dentate line

UB UB epith-cranial part vesicoureth canal trigone epith-mesonephric duct m&serous wall-splanchnopleuric mesoderm

mesonephric tubule mal-efferent ductule, ductus aberrant sup,ductus aberrant inf fem-epoophoron, paraoophoron

fetal circulation→ → → → → umbilical v(O2 bld) (lt br portal v IVC ),(ductus venosus IVC) RA (foramen

→ → → → → → →ovale LA),(RV pulm a lung pulm v LA) LV aorta

heart cardiac jelly-endocard floor fossa ovalis-septum primum

eyestructure-derived from sclera,corneal stroma& endothelium, Schlem canal, trabecular meshwork, ciliary body m-neural crest retina, iris, ciliary body epith, dilator& sphinct pupillae, sec&tert vitreous-optic cup/neuroepithelium/neuroectoderm corneal&conj epith&gld, lens, lacrimal gld-surface ectoderm EOM, bld vess, priM vitreous-Mesoderm

development of a(p498/212) maxillary a-1st arch arch of aorta-lt horn of aortic sac+ lt 4th arch a

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brachioceph a-rt horn aortic sac lt subclavian a-lt 7th cerv interseg a rt subclavian a-rt 4th arch a+ rt 7th cerv intersegm a comm carotid-3rd arch a, give bud for ext carotid& itself continues as int carotid a pulm a-6th arch a ductus arteriosu-lt 6th arch a b/n lung bud& dorsal aorta(closes immed after birth) descend thoracic aorta-lt dorsal aorta double aortic arch-persist rt 4th arch a

axis a UL-7th cerv intersegmental a LL-5th lumbar intersegmental a

v drain in sinus venosus umb v(fr placenta) vitelline v(fr yolk sac) comm cardinal v(fr body wall)

development of v int jugul v-ant card v cranial to attachm of subclav v rt brachicep v-rt ant card v b/n subclav v& anastomosis lt brachicep v-lt ant card v b/n subclav v&anastom & anastomos itself SVC-rt ant card v below anast& rt comm cardin v(duct of Cuvier) coronary sinus-lt horn sinus venosus& lt comm card v

IVC-rt Vitelline v, lowest part of post cardinal v, lower part rt supracardinal v, rt supracardinal-subcardinal anast, rt subcardinal v, subcardinal-hepatocardia anast, rt hepatocardiac channel rt common iliac v-caudal part of rt post cardinal v lt common iliac v-anast b/n 2post cardinal v rt renal v-rt mesonephric v lt renal v-lt mesonephri v, lt subcardinal v, intersubcardinal anast suprarenal& gonadal v-subcardinal v

developm of diaphragm(chr15q) septum transversum-central tendon dorsal mesoesoph-median part, crurae ventral mesentry esoph pleuroperitoneal memb body wall cervical myotome-m

developm of CNS

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neural tube ependymal mantle ventral-basal lamina-motor nuclei groove-sulcus limitans

dorsal-alar lamina-sens-sensor nucl, cerebellum&nuclei, substantia nigra, inf olivary nucl marginal

neural plat(ectoderm overlying notocord) brain(cranial part) prosencephalon(forebrain) diencephalon thalamus hypothalamus epithalamus 3rd ventricle optic cup(retina) optic stalk pituitary gld pineal gld

telencephalon cerebral hemisphere corpus striatum lat ventricle

mesencephalon(midbrain) midbrain

cerebral aqueduct rhombencephalon(hindbrain) metencephalon pons cerebellum

myelencephalon medulla oblongata spinal(caudal part)

→fetal struct derivative obl lt umb v-lig teres non obl umb art(prox)-sup vesical a obl umb a(dist)-medial umb lig(divide direct hernia into medial&lat) fold of periton which cover inf epigastric vess-lat umb lig(divide direct& indirect hernia) ductus venosus-lig venosum

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foramen ovale-fossa ovalis fossa ovalis floor-septum primum ductus arteriosum-lig arteriosum obl urachus/allantois/weeping umbilic-median umbilical lig Notochord-Nucleus pulposus

structure-degenerated part of tibial collateral lig-add magnus fib collat lig-peron longus oblique poplit lig-semimembranosus sacrotuberous lig-long head biceps fem, gluteus maximus sacrospinous lig-coccygeus art disc of TM jt-lat pterygoid articularis genu-vast intermedius anconeus-med head of triceps Sibson fascia-scal minimus(pleuralis)

pancr dorSal pancr bud-up part of head, neck, body, tail-Santorini duct ventral pancr bud-low part head, uncinat process-Wirsung duct

lung 1st stage-pseudoglandular

develop of pinna(6hillock) 1-tragus 2- 3-helix 4-antihelix 5- 6-antitragus

pharyngeal arch1. CNV3

Meckel cartilage incus malleus anterior ligament of the malleus sphenomandibular ligament maxilla mandible zygomatic bone palatine bone

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part of the temporal bone medial&lateral pterygoid masseter temporalis mylohyoid anterior belly of digastric tensor tympani tensor palati tragus maxillary a ECA

2. CNVII stapes styloid process stylohyoid ligament(fr sheath) smaller(lesser) cornu of hyoid bone superior part of body of hyoid bone Reichter cart m of face occipitofrontalis platysma stylohyoid posterior belly of digastric stapedius auricular m pinna except tragus stapedial a

3. CNIX greater cornu of hyoid bone lower part of the body of hyoid bone stylopharyngeus CCA ICA

4. SLN thyroid cart epiglottis corniculate cuneiform cricoid cricothyroid all intrinsic m soft palate levator veli palatini rt 4th aortic arch a-rt subclav a

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lt 4th aortic arch a-aortic arch6. RLN

arytenoid m of larynx& pharynx except cricothyr rt 6th aortic arch a-rt pulm a lt 6th aortic arch a-lt pulm a+ DA

pharyngeal ectodermal cleft1.dorsal-pinna, EAC

pharyngeal endodermal pouch1.dorsal-tubotympanic recess-tympani cavity, EAC

ventral-fuse with 2& form palatintonsil2.dorsal-tubotympanic recess(prox-pharyngotympanic tube)

ventral-palatine tonsil3.dorsal-inf parathyroid gld

ventral-thymus4.dorsal-sup parathyroid gld

ventral-ultimobranchial body-parafollicular cell thy(neural crest)

inner ear-otic capsule

developm tongue epith

⅔ ant -2lingual swelling(1st arch), tuberculum impar⅓ post -cranial part hypobranchial eminence(copula)(3rd arch)

postmost&epiglottis-caudal part hypobranch eminence(4th arch) m occipital myotome palatoglossus-6th arch

defect-nonfusion midline upper lip cleft-2med nasal proc hare/cleftlip-maxil proc with med nasal proc obliq facial cleft-maxil proc with lat nasal proc midline lower lip cleft-2mandib proc

tooth developm neural crest mesenchymal cell dental papilla

→ odontoblast dentine tooth pulp surf Ectoderm

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inner Epith cell→ AMELoblast EnAMEL

ventral mesogastrium falciform lig, lig teres, paraumbilic v lesser omentum rt triang lig

dorsal mesogastrium gastrosplenic lig-short gastric vess, lt gastroepiploic vess lienorenal lig-splenic vess, tail of pancr greater omentum, gastrophrenic lig

Spleen lobulation related to-Sup border

Abbreviations a-artery, AA-amino acid, abtc-antibiotic, AI-autoimmune bef-before, bel-below, b/l-bilateral, bld-blood, b/n-between, bn-benign, br-branch, Bx-biopsy ca-carcinoma, carb-carbohydrate, c/i-contraindication, c/l-contralateral, conc-concentration, cong-congenital, Cx-cervix d-day, def-deficient, ds-disease, d/t-due to, Dx-diagnosis E-estrogen fem-female, fr-from gld-gland, glu-glucose h-hormone idiop-idiopathic, i/l-ipsilateral, inf-infection, inj-injury lig-ligament, LL-lower limb, l/t-leading to m-muscle, maj-major, mal-male, MC-most common, met-metastasis, min-minor, mtx-methotrexate, Mx-management n-nerve, norm-normal P-progesterone, pl-plasma, prot-protein, pt-patient Rx-treatment SCC-squamous cell carcinoma, sr-serum, Sx-surgery, sz-seizure tm-tumour, ts-tissue UL-upper limb, u/l-unilateral vag-vagina, VC-vocal cord, vel-velocity, vert-vertebra, vit-vitamin, vol-volume w-week, wt-weight Xr-X ray y-year #-fracture °-degree

THESE NOTES ARE ONLY FOR THE PURPOSE OF GUIDANCE AND HELP TO PG ASPIRANTS, NOT FOR COMMERCIAL OR OTHER PURPOSE. REFERENCE HAS BEEN TAKEN FROM VARIOUS STANDARD TEXTBOOKS.

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