Embryology Flashcards
What is a conceptus?
Fertilisation-> end of week 3
Embryo?
Week 4->week 8
Foetus?
Week 9-> Birth
What is gametogenesis?
Germ cell formation
Oogenisis>oocyte
Spermatpgenesis>Spermatozoa
Fertilisation?
Fusion of sperm cell and oocyte to form zygote
When is a zygote formed?
In fertilisation
Cleavage definition?
Period of rapid cell division
Definition of gastrulation?
Formation of germ layers
Ecto
Meso derms
Endo
Formation definition?
Embryonic folding
Organogenesis?
Formation of organs and organ systems
Different stages of an embryo?
Gametogenesis Fertilisation Cleavage Gastrulation Formation Organogenesis
What major processes occur during embryology?
Cell division Differentiation Cell attachment Apoptosis Induction Migration
How development of embryo is regulated?
Genetic
Epigenetic
Environmental
Where does fertilization take place?
Ampulla
What does sperm bind to in fertilization?
Zona pellucida glycoprotein
What helps sperm digest its way into the egg?
Acrosomal enzymes
What does sperm entry into an egg trigger?
Completion of meiosis 2 and release of cortical granules by oocyte
What is a zygote?
Sperm and oocyte
Explain the process of cleavage?
The zygote undergoes a series of mitotic divisions which leads to many daughter cells called blastomeres
When does a zygote become a blastocyst?
When 8 blastomere daughter cells are produced compaction takes place to form blastocyst
Where does implantation take place?
Middle or upper uterine wall
Where would an ectopic implantation occur?
Ovary, ampulla, uterine tube
Ectoderm?
Epidermis of skin
Nervous system
Mesoderm?
Subdivided into 3 parts
Endoderm?
Lining of gut tube & respiratory tract
When is the embryo at most risk of defects?
Weeks 3-8
What stage does the heart develop?
Week 4
What separates the atria in an adult heart?
Interatrial septum
What does incomplete closure of the embryonic foramen ovale in the interatrial septum lead to?
Atrial septal defect (ASD)
What separates the left from the right ventricle in the adult heart? What does incomplete closure in this lead to?
The inter-ventricular septum
-Ventricular septal defect (VSD)
2 abnormalities of adult heart?
Transposition of great vessels
Tetralogy of fallot
What is transposition of great vessels?
Adult heart defect
- aorta emerges from right ventricle, and pulmonary trunk from left
What is tetralogy of fallot?
Pulmonary stenosis
Right ventricular hypertrophy
VSD
Overriding aorta
