Hypothalamus

The hypothalamus is located, as the name would suggest, below the thalamus, and is intimately associated with both the limbic system and the pituitary gland.

Gross anatomy

Boundaries

Its boundaries are in some places poorly defined (outlined in blue in Figure 2):

Fiber tracts
  • postcommissural fornix: running posterior to the anterior commissure vertically down to end in the mamillary bodies
  • principal mammillary bundle: originates in the mamillary body and runs superiorly a short distance before dividing into
    • mammillothalamic tract (a.k.a. Vicq d'Azyr bundle): terminates in the anterior thalamic nucleus
    • mammillotegmental tract (smaller)
Nuclei

The hypothalamus is really a collection of nuclei arranged symmetrically around its floor and lateral walls, and can be divided into medial and lateral areas.

Medial area
  • supraoptic (anterior)
    • supraoptic nucleus (medial part)
    • suprachiasmatic nucleus
    • medial preoptic nucleus
    • paraventricular nucleus
    • anterior nucleus
  • tuberal 
    • dorsomedial nucleus
    • ventromedial nucleus
  • mammillary (posterior)
    • mammillary nuclei
    • posterior nucleus
Lateral area
  • supraoptic (anterior)
    • lateral preoptic nucleus
    • supraoptic nucleus (lateral part)
    • lateral nucleus (anterior part)
  • tuberal 
    • lateral nucleus (tuberal part)
    • lateral tuberal nuclei
  • mammillary (posterior)
    • lateral nucleus (posterior part)

Blood Supply

  • Anterior: branches of ACA/ACOM
  • Tuberal: branches of PCOM, superior hypophyseal artery
  • Posterior: branches of PCA
  • Infundibulum: superior hypophyseal arteries from ophthalmic branch of ICA (C6)