Pituitary and Hypothalamus Flashcards
Name the basic life functions of the Hypothalamous
- Regulation of circadian rhythm (pineal gland)
- Food intake, thirst
- Stress response, sexual, defensive behaviors
- Thermoregulation
Where are the clusters of nuclei of the hypothalamus located?
Lateral walls and floor of 3rd ventricle
Borders of the hypothalamus?
Anteriorly: Lamina terminalis and anterior pillars of fornix
Posteriorly: Tegmentum mesencephalon (mamillary bodies)
Laterally: Optic tracts
What are the 3 layers of hypothalamic nuclei and what is the relation with the pituitary ?
Periventricular zone - Ant pituitary
Medial HypoThal - Post pituitary
Lateral Hypothal - Autonomous system
What are the 3 groups of hypothalamic nuclei?
Anterior : Supraoptic
Middle: Tuberal
Posterior: Mammillary
What is the name of the anterior group of HypoThal nuclei?
Supraoptic region
Which nuclei secrete ADH?
Supra-optic nucleus and Paraventricular nucleus
Which nucleus secretes melatonin?
Suprachiasmatic nucleus with pineal gland
Name three entities that can appear as a bright T1 nodule in the suprasellar cistern
Ectopic neurohypophysis
Lipoma
Rathke’s cleft cyst
Where is ADH secreted and stored?
It is secreted by the supra-optic and the paraventricular nuclei, transported by the stalk and stored in the posterior hypophysis
how does the hypothalamo-pituitary complex functions?
HThal secretes hormones (ADH)
or
HThal secretes releasing hormones (to stimulate the adenohypophysis)
Technical parameters imaging pituitary
Spin Echo, High Res, <2.5mm
Best sequence to image the pituitary-hypothalamic axis?
Axial T1
Embryology of pituitary gland
2 origins ectodermal from nasopharynx invaginates the sphenoid bone and meets the neuroectoderm
What is the Rathke’s pouch?
The embryological gap in the invaginating ectoderm between the pars intermedia and the pars anterior
