gastrula

[ gas-troo-luh ]

noun

, Embryology.

, plural gas·tru·las, gas·tru·lae [gas, -tr, oo, -lee].

1. a metazoan embryo in an early state of germ layer formation following the blastula stage, consisting of a cuplike body of two layers of cells, the ectoderm and endoderm, enclosing a central cavity, or archenteron, that opens to the outside by the blastopore: in most animals progressing to the formation of a third cell layer, the mesoderm.

gastrula

/ ˈɡæstrʊlə /

noun

1. a saclike animal embryo consisting of three layers of cells (ectoderm, mesoderm, and endoderm) surrounding a central cavity (archenteron) with a small opening (blastopore) to the exterior See also ectoderm mesoderm endoderm

gastrula

/ găs′trə-lə /

, Plural gastrulas găs′trə-lē′

1. An animal embryo at the stage following the blastula. The gastrula develops from the blastula by invagination (inpocketing), forming an inner cavity with an opening and causing the cells to be distributed into an outer layer (ectoderm) and an inner layer (endoderm). In complex animals such as vertebrates, a third layer (mesoderm) also forms. These layers later develop into the organs and tissues of the body. In vertebrates and other deuterostomes, the opening of the gastrula becomes the anus, while in protostomes (such as arthropods), it becomes the mouth.
2. ◆ The development of an embryo from blastula to gastrula is called gastrulation.
3. Compare blastula

Derived Forms

• ˈgastrular, adjective

Other Words From

• gastru·lar adjective
• pre·gastru·lar adjective

Word History and Origins

Origin of gastrula¹

From New Latin, dating back to 1875–80; gastro-, -ule

Word History and Origins

Origin of gastrula¹

C19: New Latin: little stomach, from Greek gastēr belly

Example Sentences

As Prof. Holstein underscores, the data obtained paint a new picture of the predatory lifestyle as a primary characteristic of the cnidarian gastrula.

From Science Daily

The latest work provides compelling insight into how the early human embryo transitions from a floating hollow ball of cells to a three-layered gastrula attached to the uterus.

From Nature

Such hybrids typically die before they reach the gastrula stage, the point in embryonic development at which major cell differences first become obvious.

From Scientific American

It has usually been regarded as representing both endoderm and mesoderm, and the groove which usually leads to its formation has been compared to the abnormally elongated blastopore of a typical gastrula.

From Project Gutenberg

The primitive enteron or undifferentiated digestive sac of a gastrula or other embryo.

From Project Gutenberg