Embryology Flashcards
When does surfactant production begin?
20 weeks gestation
When does surfactant start to be distributed thoughout the lungs?
Weeks 28-32
When does surfactant reach sufficient concentration?
Week 35
What is the function of the foramen ovale?
Bypass of blood from the right to left atrium
What is the function of the ductus arteriosus?
Bypass of blood from the pulmonary trunk (from the RV) into the aorta
What supportive tissue fills the umbilical cord?
Wharton’s jelly
When do foetal lungs mature?
32-34 weeks
What is a zygote?
Fertilised ovum
What is a gamete?
A reproductive cell containing only one set of chromosomes i.e. sperm, ovum
What is the function of the ductus venosus?
Shunts foetal blood from the umbilical vein to the IVC, bypassing hepatic circulation
Which embryological tissue gives rise to muscle, bone, connective tissue and the serous lining of body cavities?
Mesoderm
Which germ cell layer gives rise to the nervous system?
Ectoderm
Which germ cell layer gives rise to the liver, thymus, thyroid, parathyroids, pancreas, and the epithelial lining of the urinary bladder, urethra, respiratory tract and GIT?
Endoderm
What is gastrulation?
The formation of the trilaminar disc
3rd and 4th week of development
When is the embryo most susceptible to teratogens?
Week 3-8 when organogenesis is occuring
