Editing Pituitary gland (section)

==Other animals==
The pituitary gland is found in all vertebrates, but its structure varies among different groups.

The division of the pituitary described above is typical of [[mammal]]s, and is also true, to varying degrees, of all [[tetrapod]]s. However, only in mammals does the posterior pituitary have a compact shape. In [[lungfish]], it is a relatively flat sheet of tissue lying above the anterior pituitary, but in [[amphibian]]s, [[reptile]]s, and [[bird]]s, it becomes increasingly well developed. The intermediate lobe is, in general, not well developed in any species and is entirely absent in birds.<ref name="VB" />

The structure of the pituitary in fish, apart from the lungfish, is generally different from that in other animals. In general, the intermediate lobe tends to be well developed, and may equal the remainder of the anterior pituitary in size. The posterior lobe typically forms a sheet of tissue at the base of the pituitary stalk, and in most cases sends irregular finger-like projection into the tissue of the anterior pituitary, which lies directly beneath it. The anterior pituitary is typically divided into two regions, a more anterior ''rostral'' portion and a posterior ''proximal'' portion, but the boundary between the two is often not clearly marked. In [[elasmobranch]]s, there is an additional, ''ventral lobe'' beneath the anterior pituitary proper.<ref name="VB"/>

The arrangement in [[lamprey]]s, which are among the most primitive of all fish, may indicate how the pituitary originally evolved in ancestral vertebrates. Here, the posterior pituitary is a simple flat sheet of tissue at the base of the brain, and there is no pituitary stalk. Rathke's pouch remains open to the outside, close to the nasal openings. Closely associated with the pouch are three distinct clusters of glandular tissue, corresponding to the intermediate lobe, and the rostral and proximal portions of the anterior pituitary. These various parts are separated by [[meninges|meningial]] membranes, suggesting that the pituitary of other vertebrates may have formed from the fusion of a pair of separate, but associated, glands.<ref name="VB"/>

Most [[armadillos]] also possess a neural secretory gland very similar in form to the posterior pituitary, but located in the tail and associated with the [[spinal cord]]. This may have a function in [[osmoregulation]].<ref name="VB"/>

There is a structure [[Homology (biology)|analogous]] to the pituitary in the [[octopus]] brain.<ref>{{cite journal |last1=Wells |first1=M. J. |last2=Wells |first2=J. |year=1969 |title=Pituitary Analogue in the Octopus |journal=[[Nature (journal)|Nature]] |volume=222 |issue=5190 |pages=293–294 |doi=10.1038/222293a0 |pmid=5778406 |bibcode=1969Natur.222..293W |s2cid=4159935 }}</ref>

=== Intermediate lobe ===
Although rudimentary in humans (and often considered part of the [[anterior pituitary]]), the [[Pars intermedia|intermediate lobe]] located between the anterior and posterior pituitary is important to many animals. For instance, in fish, it is believed to control physiological color change. In adult humans, it is just a thin layer of cells between the anterior and posterior pituitary. The intermediate lobe produces [[melanocyte-stimulating hormone]] (MSH), although this function is often (imprecisely) attributed to the anterior pituitary.{{fact|date=September 2024}}

The intermediate lobe is, in general, not well developed in tetrapods, and is entirely absent in birds.<ref name=VB>{{cite book |author=Romer, Alfred Sherwood|author2=Parsons, Thomas S.|year=1977 |title=The Vertebrate Body |publisher=Holt-Saunders International |location= Philadelphia, PA|pages= 549–550|isbn= 0-03-910284-X}}</ref>