embryogenesis An embryo is an initial stage of development of a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male spe ...

, Rathke's pouch is an evagination at the roof of the developing mouth in front of the buccopharyngeal membrane. It gives rise to the

anterior pituitary A major organ of the endocrine system, the anterior pituitary (also called the adenohypophysis or pars anterior) is the glandular, anterior lobe that together with the posterior lobe (posterior pituitary, or the neurohypophysis) makes up the pi ...

(adenohypophysis), a part of the

endocrine system The endocrine system is a messenger system comprising feedback loops of the hormones released by internal glands of an organism directly into the circulatory system, regulating distant target organs. In vertebrates, the hypothalamus is th ...

Development

Rathke's pouch, and therefore the anterior pituitary, is derived from

ectoderm The ectoderm is one of the three primary germ layers formed in early embryonic development. It is the outermost layer, and is superficial to the mesoderm (the middle layer) and endoderm (the innermost layer). It emerges and originates from t ...

. The pouch eventually loses its connection with the

pharynx The pharynx (plural: pharynges) is the part of the throat behind the mouth and nasal cavity, and above the oesophagus and trachea (the tubes going down to the stomach and the lungs). It is found in vertebrates and invertebrates, though its st ...

giving rise to the

. The anterior wall of Rathke's pouch proliferates, filling most of the pouch to form '' pars distalis'' and ''

pars tuberalis The pars tuberalis is part of the anterior lobe of the pituitary gland, and wraps the pituitary stalk in a highly vascularized sheath. Histology Principal cells of the pars tuberalis are low columnar in form, with the cytoplasm containing numer ...

''. The posterior wall forms ''

pars intermedia Pars intermedia is the boundary between the anterior and posterior lobes of the pituitary. It contains colloid-filled cysts and two types of cells - basophils and chromophobes. The cysts are the remainder of Rathke’s pouch. In human fetal ...

''. In some organisms, the proliferating anterior wall does not fully occupy Rathke's pouch, leaving a remnant (Rathke's cleft) between the ''pars distalis'' and ''pars intermedia''.

Clinical significance

Rathke's pouch may develop benign

cysts A cyst is a closed sac, having a distinct envelope and division compared with the nearby tissue. Hence, it is a cluster of cells that have grouped together to form a sac (like the manner in which water molecules group together to form a bubble) ...

Craniopharyngioma A craniopharyngioma is a rare type of brain tumor derived from pituitary gland embryonic tissue that occurs most commonly in children, but also affects adults. It may present at any age, even in the prenatal and neonatal periods, but peak incidence ...

is a neoplasm which can arise from the epithelium within the cleft.

Eponym

It is named for

Martin Rathke Martin Heinrich Rathke (25 August 1793, Danzig – 3 September 1860, Königsberg) was a German embryologist and anatomist. Along with Karl Ernst von Baer and Christian Heinrich Pander, he is recognized as one of the founders of modern embryol ...

.M. H. Rathke. Entwicklungsgeschichte der Natter (Coluber natrix). Königsberg, Bornträger, 1839.

References

External links

* *
Diagram at cushings-help.com
* https://web.archive.org/web/20070930075847/http://www.lib.mcg.edu/edu/eshuphysio/program/section5/5ch2/s5ch2_2.htm {{Development of digestive system Embryology of digestive system

Development

Clinical significance

Eponym

See also

References

External links