Rathke's pouch
Encyclopedia
In embryogenesis
, Rathke's pouch is a depression in the roof of the developing mouth in front of the buccopharyngeal membrane
. It gives rise to the anterior pituitary
(adenohypophysis), a part of the endocrine system
.
giving rise to the anterior pituitary
. The anterior wall of Rathke's pouch proliferates, filling most of the pouch to form pars distalis and pars tuberalis
. The posterior wall forms pars intermedia
.
In some organisms (humans being a notable exception), the proliferating anterior wall does not fully occupy Rathke's pouch, leaving a remnant (Rathke's cleft) between the pars distalis and pars intermedia.
) is a neoplasm which can arise from the epithelium within the cleft.
Embryogenesis
Embryogenesis is the process by which the embryo is formed and develops, until it develops into a fetus.Embryogenesis starts with the fertilization of the ovum by sperm. The fertilized ovum is referred to as a zygote...
, Rathke's pouch is a depression in the roof of the developing mouth in front of the buccopharyngeal membrane
Buccopharyngeal membrane
The region where the crescentic masses of the ectoderm and endoderm come into direct contact with each other constitutes a thin membrane, the buccopharyngeal membrane , which forms a septum between the primitive mouth and pharynx...
. It gives rise to the anterior pituitary
Anterior pituitary
A major organ of the endocrine system, the anterior pituitary, also called the adenohypophysis, is the glandular, anterior lobe of the pituitary gland...
(adenohypophysis), a part of the endocrine system
Endocrine system
In physiology, the endocrine system is a system of glands, each of which secretes a type of hormone directly into the bloodstream to regulate the body. The endocrine system is in contrast to the exocrine system, which secretes its chemicals using ducts. It derives from the Greek words "endo"...
.
Development
The pouch eventually loses its connection with the pharynxPharynx
The human pharynx is the part of the throat situated immediately posterior to the mouth and nasal cavity, and anterior to the esophagus and larynx. The human pharynx is conventionally divided into three sections: the nasopharynx , the oropharynx , and the laryngopharynx...
giving rise to the anterior pituitary
Anterior pituitary
A major organ of the endocrine system, the anterior pituitary, also called the adenohypophysis, is the glandular, anterior lobe of the pituitary gland...
. The anterior wall of Rathke's pouch proliferates, filling most of the pouch to form pars distalis and pars tuberalis
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:...
. The posterior wall forms pars intermedia
Pars intermedia
Pars intermedia is the boundary between the anterior and posterior lobes of the pituitary. It contains three types of cells - basophils, chromophobes, and colloid-filled cysts. The cysts are the remainder of Rathke’s pouch....
.
In some organisms (humans being a notable exception), 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. (CraniopharyngiomaCraniopharyngioma
Craniopharyngioma is a type of brain tumor derived from pituitary gland embryonic tissue, that occurs most commonly in children but also in men and women in their 50s and 60s....
) is a neoplasm which can arise from the epithelium within the cleft.
External links
- Diagram at cushings-help.com
- http://www.lib.mcg.edu/edu/eshuphysio/program/section5/5ch2/s5ch2_2.htm
