Endocrine - Pituitary Development

Introduction

Adult pituitary

Historically, this endocrine gland was called the "pituitary" as it was originally thought to produce mucous that discharged through the nose. We now know that this is not the function of the pituitary, or hypophysis which is an endocrine gland links the brain to peripheral endocrine organs and systems of the body through several specific hormones. The developmental origin of the hypophysis is also unique, epithelial origins from neural ectoderm (posterior) and from surface ectoderm (anterior).

During development, the boundary epitheilal ectoderm in the roof of the pharynx forms a pocket (Rathke's pouch) that comes into contact with the ectoderm of developing brain. Rathke's pouch is named after German embryologist and anatomist Martin Heinrich Rathke (1793 ‚Äî 1860).

Anatomically, the pituitary has 2 main parts posterior, or neurohypophysis and anterior, or adenohypophysis (the pars distalis, pars intermedia, and pars tuberalis). Between the two a specialized vascular (portal) system allows communication from the brain to peripheral endocrine organs and other systems. File:17thC-turkish-saddle3.jpg

The pituitary is located within the pituitary fossa of the sphenoid bone, anterior to the lamina terminalis and superior to the pharynx. The shape of the bone surrounding the pituitary led to the naming sella turcica (Latin sella = saddle, turcica = Turkish), as it resembled a saddle shape.

Pit1 (pituitary-specific transcription factor) is a transcription factor important for pituitary development and muations in this gene can lead to abnormalities in pituitary development and hormone production. (More? [../MolDev/factor/pit.htm Molecular Development Factors - Pit])

Anterior pituitary hormones - Thyroid-stimulating hormone (TSH), Adrenocorticotrophic hormone (ACTH), Luteinizing hormone (LH), Follicle-stimulating hormone (FSH), Somatotrophin/growth hormone (GH), Prolactin (PRL), Melanocyte-stimulating hormone (MSH)

Posterior pituitary hormones - Oxytocin, Arginine vasopressin

Historic Embryology - Endocrine
1903 Islets of Langerhans \| 1903 Pig Adrenal \| 1904 interstitial Cells \| 1908 Pancreas Different Species \| 1908 Pituitary \| 1908 Pituitary histology \| 1911 Rathke's pouch \| 1912 Suprarenal Bodies \| 1914 Suprarenal Organs \| 1915 Pharynx \| 1916 Thyroid \| 1918 Rabbit Hypophysis \| 1920 Adrenal \| 1935 Mammalian Hypophysis \| 1926 Human Hypophysis \| 1927 Adrenal \| 1927 Hypophyseal fossa \| 1930 Adrenal \| 1932 Pineal Gland and Cysts \| 1935 Hypophysis \| 1935 Pineal \| 1937 Pineal \| 1935 Parathyroid \| 1940 Adrenal \| 1941 Thyroid \| 1950 Thyroid Parathyroid Thymus \| 1957 Adrenal

| Lecture - Head Development | original page

Development Overview

Pituitary rabbit development

Dual ectoderm origins
- Ectoderm - ectoderm roof of stomodeum, Rathke's pouch, adenohypophysis
- Neuroectoderm - prosenecephalon then diencephalon, neurohypophysis

Adenohypophysis