A mass of cells formed around a central cavity; an early stage of development after multiple cleavages in a zygote. © Nature Education

A thin-walled hollow structure in early embryonic development that contains a cluster of cells called the inner cell mass from which the embryo arises. The outer layer of cells gives rise to the placenta and other supporting tissues needed for fetal development within the uterus while the inner cell mass cells gives rise to the tissues of the body.

[Gk. blastos, sprout + kystis, sac] An embryonic stage in mammals; a hollow ball of cells produced one week after fertilization in humans.

Mammalian embryo at the stage at which it is implanted into the wall of the uterus. [9]

1876, from blasto- + cyst.

The developing pre-embryo shortly before implantation when it is a hollow ball of cells.

A stage during early embryogenesis in mammals in which the embryo develops a fluid-filled interior and segregates into trophoblast and inner cell mass.

An early stage of embryonic development consisting of a hollow ball of cells;a small ball of cells representing an early stage of embryonic development. blastoderm

n. in embryology, refers to an inner cell mass surrounded by a layer of outer cells known as the trophoblast. It is formed 5 to 6 days after fertilization. After completing its journey through the fal [..]

The early stage in development of a mamalian embryo.

The early stage of embryonic development when the morula

  The spherical structure produced by cleavage of the fertilized ovum, consisting of a single layer of cells (blastoderm) surrounding a fluid-filled    cavity (blastocoele). 

A structure formed in the early mammalian embryogenesis, after formation of the morula.

(n) the blastula of a placental mammal in which some differentiation of cells has occurred

The early stage in the development of the mammalian embryo (often the point at which development is arrested in delayed implantation).

A blastocyst is a precursor of an embryo, and is characterised by a hollow sphere with an outer layer of squamous cells called the trophoblast and an inner layer known as the inner cell mass. It is fo [..]

A post-Morula preimplantation Mammalian Embryo that develops from a 32-Cell stage into a fluid-filled hollow ball of over a hundred Cells. A blastocyst has two distinctive Tissues. The outer layer of [..]

Early preimplantation mammalian EMBRYO in the post-MORULA stage. Its structure consists of a TROPHOBLASTS-enclosed fluid-filled cavity with an inner cell mass. After EMBRYO IMPLANTATION, the inner cel [..]

A preimplantation embryo of about 150 cells. The blastocyst consists of a sphere made up of an outer layer of cells (the trophectoderm), a fluid-filled cavity (the blastocoel) and a cluster of cells on the interior (the inner cell mass).

After a mammalian ovum is fertilised it begins to divide. The blastocyst is an early stage of this process which consists of a sphere that is fluid-filled and surrounded by a layer of cells, surrounding a fluid-filled cavity. There is a mass of cells at one side which will become the embryo. The blastocyst is formed before implantation into the ute [..]

An early embryo, about 4–7 days after fertilisation, which consists of a hollow ball of cells filled with fluid.

an early stage of embryonic development in which some tissue differentiation has occurred, typically 3-5 days post fertilisation in humans.

cleavage stage mammalian embryo; a hollow ball of cells made of outer trophoblast cells and an inner cell mass.

An embryo made up of two groups of cells. One group will develop into the fetus and the other will become the placenta.

the modified blastula stage of mammalian embryos

A stage of embryo development approximately 5 or 6 days after egg collection.

An embryo, 5 or 6 days after fertilization, with an inner cell mass, outer layer of trophectoderm, and a fluid-filled blastocele cavity.

The term for an embryo five days after fertilisation which has now developed a distinctive shape with different parts clearly identifiable within its fluid-filled cavity.

A very early embryo consisting of approximately 150 cells. The blastocyst is a spherical cell mass produced by cleavage of the zygote (fertilized egg). It contains a fluid-filled cavity, a cluster of cells called the inner cell mass (from which embryonic stem cells are derived) and an outer layer of cells called the trophoblast (that forms the plac [..]

One of the earliest stages of an embryo.