In
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 sperm ...
, 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 p ...
(adenohypophysis), a part of the
endocrine system.
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 giving 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 p ...
. The anterior wall of Rathke's pouch proliferates, filling most of the pouch to form ''
pars distalis
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 pit ...
'' 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 numero ...
''. 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 life ...
''.
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 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.]
See also
*
Rathke's cleft cyst
A Rathke's cleft cyst is a benign growth on the pituitary gland in the brain, specifically a mucin-filled cyst in the posterior portion of the anterior pituitary gland. It occurs when the Rathke's pouch does not develop properly and ranges in siz ...
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