About Lesson
Pituitary Glands
- The pituitary gland occupies the same central part of the endocrine signaling system of fish that it has in mammals.
- The pituitary gland is located below the diencephalon (hypothalamus), behind the optic chiasma, and anterior to the saccus vasculosus, and is attached to the diencephalon by a stalk or infundibulum.
- The size of the infundibulum varies according to the species. Usually, in cyclostomes, it is smaller but increases in bony fishes, with prominence in the groove or depression of the parasphenoid bone receiving the gland.
- There is no sella turcica comparable to that found in mammals in Xiphophorus.
- The short, thick-walled, hollow infundibular stalk contains a lumen, which continues with the third ventricle.