The cerebellum, meaning "the little brain"sits at the base of the brain in the posterior cranial fossa below the tentorium and behind the brainstem

The cerebellum has the following features:

  • three surfaces: anterior (petrosal), superior (tentorial), inferior (suboccipital)
  • three fissures: primary (tentorial), horizontal (petrosal), prebiventral/prepyramidal (suboccipital)
  • two hemispheres
  • single median vermis

The vermis is divided into nine lobules: (in a clockwise rotation, looking at the patient sagittally from his left), and separated into groups by fissures:

  • lingula
  • central lobule
  • culmen: primary (tentorial) fissure
  • declive
  • folium: horizontal (petrosal) fissure
  • tuber: prebiventral/prepyramidal (suboccipital) fissure
  • pyramid
  • uvula
  • nodulus

The subdivisions of the cerebellar vermis can be remembered by this mnemonic.

The cerebellar folia run parallel to the calvaria in an onion-like configuration.

Each of the nine vermis lobules is associated in both sides with two cerebellar hemisphere lobules and therefore the cerebellum has 18 cerebellar hemisphere lobules:

  • wing of lingula (lingula)
  • wing of central lobule (central lobule)
  • quadrangular lobule (culmen): primary (tentorial) fissure
  • simple lobule (declive)
  • superior semilunar lobule (folium): horizontal (petrosal) fissure
  • inferior semilunar lobule (tuber): prebiventral/prepyramidal (suboccipital) fissure
  • biventral lobule (pyramid)
  • tonsil (uvula)
  • flocculus (nodulus)

The cerebellum is essentially supplied by three bilateral vessels from the vertebrobasilar system:

  1. superior cerebellar artery (SCA): branch of the distal basilar artery
  2. anterior inferior cerebellar (AICA): branch of the proximal basilar artery
  3. posterior inferior cerebellar (PICA): branch of the distal vertebral arteries

The SCA supplies:

  • whole superior surface of the cerebellar hemispheres down to the great horizontal fissure
  • the superior vermis
  • dentate nucleus
  • most of the cerebellar white matter
  • superior cerebellar peduncle
  • middle cerebellar peduncle

The AICA has a variable vascular territory depending on the size of the PICA (see AICA-PICA dominance) but usually supplies:

  • middle cerebellar peduncle
  • inferolateral portion of the pons
  • flocculus
  • anteroinferior surface of the cerebellum

The PICA has a variable vascular territory depending on the size of the AICA (see AICA-PICA dominance), but usually supplies:

  • posteroinferior cerebellar hemispheres (up to the great horizontal fissure)
  • inferior portion of the vermis
  • inferior cerebellar peduncle

It divides into lateral and medial branches that supply the inferior portion of the vermis and cerebellar hemispheres respectively.

There are some variations in the PICA:

  • 18% arise extracranially, inferior to the foramen magnum
  • 10% arise from the basilar rather than vertebral artery
  • 2% bilaterally absent
  • occasionally loops around the cerebellar tonsil
  • occasionally a small vertebral artery will terminate into a common PICA/AICA trunk
Anatomy: Brain

Anatomy: Brain

Article information

rID: 891
Synonyms or Alternate Spellings:
  • Cerebellum anatomy
  • Anatomy of the cerebellum
  • Cerebellar anatomy

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Cases and figures

  • Figure 1: vascular territories
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  • Figure 2: superior cerebellum
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  • Figure 3: mid-cerebellum
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  • Figure 4: Inferior cerebellum
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  • Cerebellum (sagittal) - Gray's anatomy illustration
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