Organogenesis of Frog

 Organogenesis of Frog

 

The primary organ rudiments from ectoderm, mesoderm and endo-derm get well established during the processes of gastrulation and neurula-tion. In the next stage the primary organ rudiments subdivide into secondary organ rudiments. These rudiments get differentiated into various organs and organ systems.

 

The development of ectodermal organs

 

The neurula of frog has three kinds of ectodermal tissues namely, epi-dermal ectoderm, neural ectoderm and neural crest cells.

 

Epidermal ectoderm

 

The epidermal derivatives are the skin, olfactory sense organs, ear, lateral line sense organs, median fins, external gills and lining of mouth and anus.

 

Neural ectoderm

 

This layer of cells form the central nervous system and peripheral nervous systems.

 

 

The development of mesodermal organs

 

The mesodermal derivatives are the limbs, endoskeleton, heart, blood vessels, kidney, coelom and reproductive organs.

 

 

The development of endodermal organs

 

The predominant endodermal organs are the organs of the alimentary canal, lungs, pancreas and urinary bladder.

 

Development of heart in Frog

 

The heart is a mesodermal derivative. It develops on the ventral side of pharynx. It is formed from the lateral plate mesoderm. Initially the heart is formed as a straight tube. Later it gets folded to form the chambered heart.

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