Embryology Flashcards
1
Q
Define the terms cleavage, morula, blastocysts, trophoblast and inner cell.
A
Cleavage
- period of fairly rapid mitotic divisions of the zygote without intervening growth.
- GOAL to produce small cells with high surface to volume ratio, which enhances their uptake of nutrients and oxygen and the disposal of wastes.
- provides large no.of cells to serve as building blocks for constructing the embryo.
Morula
- is a berry shaped cluster of 16 or more cells formed 72 hours after fertilization by loose collection of cells.
Trophoblast
- fluid filled hollow sphere composed of a single layer of large flattened cells
Inner cells
- cells and a small cluster of 20-30 rounded cells, located at one side.
Blastocyst
- consists of a sphere of trophoblast cells and inner cell mass
