Introductory Module Flashcards
What is anterior in embryological terms?
Anterior is the cranial end (towards the head)
What is posterior in embryological terms?
It is the caudal end (towards the tail end)
What are the front and back of the embryo called anatomically?
Dorsal and ventral sides
What do the polar bodies contain?
Contain haploid DNA from the female
What does 1 germ cell give rise to in females?
1 germ cell gives rise to 1 oocyte in females
What does 1 germ cell give rise to in males?
1 germ cell gives rise to 4 sperms in males
Where do the polar bodies come from?
Nuclear DNA duplicated
-Cells briefly enter meiosis then arrest after the first prophase of meiosis
- Remains in arrested state till adult life
- Only when single oocyte is selected, then meiosis resumes
- When an adult, first meiotic division occurs and 1st polar body is extruded within the perivitelline space
- Selected oocyte arrest again in meiosis 2 until fertilisation occurs
- After fertilisation meiosis resumes and 2nd polar body is extruded
Where does oocyte selection occur?
Oocyte selection occurs in the ovary
What is the oocyte collected by?
Oocyte is collected by the fimbriae
In which region does fertilisation occur?
Fertilisation occurs in the ampulla region
What are the outer and inner cells of the blastocyst?
Outer cells of the blastocyst are trophoblasts and the inner cells are known as the inner cell mass.
Where will the brain form?
On the cranial end of the notochord
How does the heart form in vivo?
Bilaterally
How can the terminal differentiation of a certain group of tissues be found from the early embryo?
The early tissues can be painted, then the painted tissues monitored during growth. This works best in in vitro embryos e.g. zebrafish and hen eggs.
How long does the embryonic period last in humans?
During the first 8 weeks of conception. Most of the organogenesis and the body plan arise during this point.
