blastosphere
Noun: 1. An early embryonic stage: The blastosphere, also called a blastocyst, is a very early stage in the development of an embryo in mammals. It is formed after the fertilized egg undergoes several rounds of cell division (cleavage). 2. A spherical structure: It is characterized by being a hollow, fluid-filled sphere. Its wall is made up of a single layer of cells called the trophoblast. Inside, a cluster of cells known as the inner cell mass is attached to one part of the wall.
The term is used specifically in the fields of embryology, developmental biology, and reproductive medicine to describe this precise morphological stage. * The blastosphere forms about five to six days after fertilization in humans. * Successful implantation depends on the blastosphere hatching from its protective shell. * Researchers studied the cell composition of the blastosphere.
- Blastosphere vs. Blastula: In general embryology, "blastula" is the more common term for this hollow ball stage in many animals. "Blastosphere" or "blastocyst" is the specific term used for mammals, highlighting the presence of a distinct inner cell mass and trophoblast layer.
- Blastocoel: The fluid-filled cavity inside the blastosphere is specifically called the blastocoel.
- Blastocyst (n): The preferred and more commonly used synonym for "blastosphere" in mammalian embryology.
- Blastulation (n): The process of forming a blastosphere/blastocyst.
- Trophoblast (n): The outer layer of cells of the blastosphere, which contributes to the placenta.
- Inner Cell Mass (n): The cluster of cells inside the blastosphere that will develop into the embryo proper.
- Blastocyst
- Blastula (in a broader, non-mammalian context)
This word has a single, highly specialized meaning in biological science. It does not have idiomatic or phrasal verb uses. Its usage is almost exclusively technical.
- early stage of an embryo produced by cleavage of an ovum; a liquid-filled sphere whose wall is composed of a single layer of cells; during this stage (about eight days after fertilization) implantation in the wall of the uterus occurs