Intro to Embryology Flashcards
(17 cards)
Why study embryology?
Understand development, structure, final form and relationships of tissues and organs
Desirable outcome of normal embryogenesis?
A normal alive foetus
Name some errors in embryogenesis
Embryonic loss
Foetal death
Foetal mummification
Abortion
Stillbirth
Nonviable neonates
Viable offspring with defects
Embryogenesis is a ___ process
Multifactoral
Molecules that can affect growth and dev
Carcinogens
Mutagens
Teratogens
What is a carcinogen?
agents or factors that initiate or induce neoplasia/carcinogens
What is a mutagen?
agents or factors that produce a change in the genetic code of an organism
What is a tetratogen?
agents or factors that cause the development of physical defects in the embryo or foetus
What is a critical period?
Period of sensitivity to external/internal factors affecting development
In-utero crowding causes…
congenital joint contracture
spinal deformities and limb abnormalities can present following…
a transverse or caudal presentation
aggressive palpation for pregnancy diagnosis can result in…
limb deformities or disruption of vascular supply
Teratogen example
white helebore ingested during early embryogenesis can cause cyclopia
Fertilisation is…
the process whereby a spermatozoon and an ovum fuse to form a single celled zygote
Two layers of the oocyte when it leaves the ovary
corona radiata (outer)
zona pellucida (inner)
How does sperm break through the corona radiata?
Enzymes released from its acrosome break through and then the membrane of the egg and sperm fuse
Two critical changes upon sperm entry
- vesicles heal the ZP to prevent additional sperm from entering
- ovum must be activated by a series of calcium waves
