ANAT2341: Week 1 and 2
DrAnnemiekBeverdam– SchoolofMedicalSciences,UNSWWallaceWurth BuildingRoom234– [email protected]
Resources ANAT2341:http://php.med.unsw.edu.au/embryology/
Larsen’s Human EmbryologyThe Developing Human: Clinically Oriented Embryology
Week 1/2 Lecture overview
DrAnnemiekBeverdam– SchoolofMedicalSciences,UNSWWallaceWurth BuildingRoom234– [email protected]
Resources:http://php.med.unsw.edu.au/embryology/
Larsen’s Human EmbryologyThe Developing Human: Clinically Oriented Embryology
Fertilization
Cleavage stages
Morula formation
Blastocyst formation
Implantation
Generation of bilaminar embryo
Endometriosis
Twinning
Week 1
Week 2
Week 1/2
Fertilization/Zygote formation
Spermatozoa Sperm Binding (SED1)Acrosome Reaction Membrane Fusion
OocyteMembrane Depolarization
Cortical Reaction Meiosis II
Zygote FormationDiploid cell
Male and Female pronuclei First mitotic division within 24h
http://php.med.unsw.edu.au/embryology/images/c/c0/Fertilization_001.mp4
Cleavage stages - Day 1-5Blastomeres
No growth (G1/G2) stagesCompaction
Trophoblast/inner cell massSynchronous/asynchronous cell division
Zona Pellucida
Fig1-16Larsen’s
Blastomere contacts and communicationTightandadherens junctions:seal Gapjunctions:communication
Hatching of the Blastocyst – Day 5
Fig1-16Larsen’s
Blastocyst hatching
Hatching (day 5)Multiple roles for zona pellucida
Ectopic pregnancies
http://php.med.unsw.edu.au/embryology/images/a/ae/Human_blastocyst_day_3-6.mp4
http://php.med.unsw.edu.au/embryology/images/b/b4/Week1_001.mp4
Week 1 of development
Fig1-16Larsen’s
Week 2: Implantation: Menstrual Cycle
hypothalamus:GnRH
Pituitary:LH- FSH
Endometrialgrowth
Folliclematuration
Estrogen
LHsurge
Ovulation
Fertilization:
Corpusluteum
Progesterone(inresponsetohCG)
Maintenanceofendometrium
Nofertilization:
Corpusalbicans
NoProgesterone
Lossofendometrium
Implantation Menses
Week1-2 Week3-4
Week 2: Implantation: Uterus
Uterine wall consists of:- Endometrium (cycling)- Myometrium (parturition)- Perimetrium (tunica serosa)
Endometrium consists of:- Basilar zone (not lost, own blood supply)- Functional (spongy) zone, ovarian gland bodies,
cycles)- Compact zone: columnar epithelium, stromal
cells, overian gland necks: implantation
Week 2: Implantation: Embryo
During receptivity window of menstrual cycleAdplantation: day 6-7Implantation: days 8-9
http://php.med.unsw.edu.au/embryology/images/a/a6/Week2_001.mp4
endometrialstroma
Adplantation Implantation
Week 2: Implantation: EmbryoTrophoblast: syncytiotrophoblast and cytotrophoblast
Inner cell mass: epiblast and hypoblast
Generation of bilaminar embryoAmniotic cavity and primary yolk sac
Syncytiotrophoblast produces:Proteolytic enzymes
Human chorionic gonadotropin hormone
http://php.med.unsw.edu.au/embryology/images/a/a6/Week2_001.mp4
endometrialstroma
Adplantation Implantation
Bilaminar EmbryoDay 10-13
http://php.med.unsw.edu.au/embryology/images/c/c1/Chorion_001.mp4
Bilaminar EmbryoDay 12-13
Extraembryonic mesoderm forms chorionic cavity (embryonic)Epiblast forms amniotic cavity (embryonic)
Blastocoel cavity becomes definitive yolk sac (embryonic) Endometrium forms the decidua (Maternal)
Bilaminar EmbryoDay 13-14
EndometriosisEctopicendometrialtissue(ovaries,fallopiantubes)
CyclesinresponsetoLHandprogesterone
Twinning
Monozygotictwinning:identicalgeneticmaterial
Typeofmonozygotictwinisdeterminedbythetimingofembryonicdivision:
A:0-4dpf:embryosplitsin2dichorionic,diamniotic
B:4-8dpf:ICMsplits,distantembryoblastsMonochorionic,diamniotic
C:8-12dpf:ICMsplits,CloseembryoblastsMonochorionic,monamnionic
D:8-12dpf:ICMsplitspartiallyMonochorionic,monamnionicConjoinedtwins
ImplantationWeek 2
Week 1/2 Lecture overview
DrAnnemiekBeverdam– SchoolofMedicalSciences,UNSWWallaceWurth BuildingRoom234– [email protected]
Resources:http://php.med.unsw.edu.au/embryology/
Larsen’s Human EmbryologyThe Developing Human: Clinically Oriented Embryology
Fertilization
Cleavage stages
Morula formation
Blastocyst formation
Implantation
Generation of bilaminar embryo
Endometriosis
Twinning
Week 1
Week 2
Labs Relevant to this Lecture
Assisted Reproductive Technology (Lab 1)
Genetic modification of mice (Lab 2)
Preimplanation and early implantation (Lab 3)
The Reproductive Technology Revolution (Lab 4)
