blastocyst
Noun: 1. An early stage embryo: A blastocyst is a structure formed in the early development of placental mammals, following the morula stage and preceding implantation in the uterine wall. It is characterized by a fluid-filled cavity and a distinct inner cell mass.
The term "blastocyst" is used specifically in the fields of embryology, developmental biology, and reproductive medicine to describe this precise stage of mammalian embryonic development.
Examples: * In human development, the fertilized egg becomes a blastocyst about five days after fertilization. * The quality of the inner cell mass is a key factor assessed during blastocyst selection for in vitro fertilization (IVF). * The study focused on the gene expression patterns in the mouse blastocyst.
- Blastocyst transfer: A procedure in IVF where an embryo is cultured to the blastocyst stage in the laboratory before being transferred to the uterus. This is done to improve synchronization with the uterine environment and potentially increase pregnancy rates.
- Blastocyst hatching: The process by which the blastocyst breaks out of its surrounding membrane (the zona pellucida), which is a necessary step for implantation into the uterine lining.
- Blastula (noun): A more general term for an early embryonic stage consisting of a sphere of cells surrounding a fluid-filled cavity. A blastocyst is a specialized type of blastula found in placental mammals.
- Trophoblast (noun): The outer layer of cells of the blastocyst, which is responsible for implantation and will eventually form a major part of the placenta.
- Inner Cell Mass (ICM) (noun phrase): The cluster of cells inside the blastocyst that will develop into the embryo proper.
- Early embryo (general term)
- Pre-implantation embryo (context-specific term)
The word "blastocyst" does not have other common meanings outside of its specific biological/medical definition related to embryonic development.
- the blastula of a placental mammal in which some differentiation of cells has occurred