blastula

American  

[blas-chuh-luh] / ˈblæs tʃə lə /

noun

Embryology.

• blastulas,
  plural
• blastulae
  plural

1. the early developmental stage of an animal, following the morula stage and consisting of a single, spherical layer of cells enclosing a hollow, central cavity.

---

blastula British  

/ ˈblæstjʊlə /

noun

1. Also called: blastosphere.  an early form of an animal embryo that develops from a morula, consisting of a sphere of cells with a central cavity

---

blastula Scientific  

/ blăs′chə-lə /

• blastulas
  plural

1. An animal embryo at the stage immediately following the division of the fertilized egg cell, consisting of a ball-shaped layer of cells around a fluid-filled cavity known as a blastocoel.

2. Compare gastrula See also blastocyst

---

blastula Cultural  

1. The stage of an embryo that consists of just over a hundred cells — a stage reached about one week after fertilization. At this stage the cells are just at the very beginning of cellular differentiation and are said to be totipotent (See totipotency).

---

Discover More

This is the stage of development where embryonic stems cells can be harvested for medical research.

Other Word Forms

Derived Forms

• blastulation
  noun
• blastular
  adjective

Inflected Forms

Nouns

• blastulae
  plural
• blastulas
  plural

Etymology

Origin of blastula

1885–90; < New Latin < Greek blast ( ós ) bud, sprout + New Latin -ula -ule

Compare meaning

How does blastula compare to similar and commonly confused words? Explore the most common comparisons:

• morula vs. blastula
• blastula vs. blastocyst
• blastula vs. gastrula

Example Sentences

See Examples For:

blastula blastulae blastulas

In mammals, the blastula forms the blastocyst in the next stage of development.

From Textbooks ● Jun. 9, 2022

Here the cells in the blastula arrange themselves in two layers: the inner cell mass, and an outer layer called the trophoblast.

From Textbooks ● Jun. 9, 2022

During gastrulation, the blastula folds upon itself to form the three layers of cells.

From Textbooks ● Jun. 9, 2022

After fertilization, the zygote develops into a blastula, which develops into a planula larva.

From Textbooks ● Jan. 1, 2015

The germinal layers form from the first closed tubes, the one-layered blastula being converted into the two-layered gastrula by invagination.

From The Evolution of Man — Volume 1 by Ernst Heinrich Philipp August Haeckel

For Ptychodera, extensive EST data from egg, blastulae, gastrulae, larvae, juveniles, adult proboscis, stomochord, and gills defining 34,159 cDNA clones53, and 879,000 Roche/454 RNAseq reads from a mixed library of developmental stages54 were used.

From Nature ● Nov. 17, 2015

I picture the embryos themselves: round blastulas, with evenly divided cells.

From Slate ● May 23, 2012

Near the end of my visit, our conversation turned from the theoretical consideration of morulas and blastulas to the specific realities of my own condition and treatment.

From Slate ● May 23, 2012