Embryology Flashcards
What is the Graafian Follicle?
A large secondary follicle with the potential for ovulation with a large antrum
What cells surround the oocyte as it leave the follicle?
Cumulus oophorus cells
What hormone signals the endometrium to proliferate?
progesterone
What secretes progesterone?
The corpus luteum
What stage of cell division is the oocyte in just before fertilisation?
Metaphase of the 2nd meiotic division
What layers must the sperm penetrate in order to fertilise the egg?
Corona radiata and the zona pellucida
What type of cell do the male and female pronuclei form when they mingle?
A diploid cell
When is the morula formed?
Day 4
Describe the blastocyst
Trophoblast formed from surrounding supporting tissue
Embryoblast forms the embryo proper
When does implantation occur?
Day 5.5.-6
Where does implantation usually occur?
Anterior or posterior portion of uterus
What does the syncytiotrophoblast do?
Secretes enzymes that allow the blastocyst to embed into the uterine wall.
At day 9 what does the blastocyst cavity become?
The exocoelomic cavity
What do amnioblasts do?
Secrete amniotic fluid into the amniotic cavity.
When does the primitive yolk sac?
Day 12
What is the purpose of the maternal sinusoids?
Supply the developing embryo with nutrients
What is the importance of the prechordal plate at 13 days?
Important in the formation of the oral cavity formed by the fusion of ectoderm and endoderm
When does gastrulation occur?
16-17 days
When is the baby known as an embryo?
Week 4-8
When is the baby known as an foetus?
Week 9-Birth
Define gametogenesis?
Germ cell formation
Define fertilisation?
Formation of the zygote
Define cleavage?
Period of rapid cell division, formation of morula then blastocyst
Define gastrulation?
Formation of germ layers and establishment of body axes
Define organogenesis?
Primordia of all organ systems
