General Organization of Cerebellum and its Division
Cerebellum – General Features
● Terminology: Cerebellum (Latin: "little brain")
● Location: Situated in the posterior cranial fossa
● Attachment: Connected to the dorsal aspect of the brainstem
● Separation: Separated from the cerebrum superiorly by the tentorium cerebelli (a
partition of dura mater)
● Growth: At birth, the cerebellum is 1/20th the size of the cerebrum; in adulthood, it is
1/8th the size
● Surface characteristics:
○ Highly convoluted with numerous fissures (sulci)
○ Narrow folds called folia (Latin: "leaves") which are mostly transverse
○ Folia increase surface area significantly, almost matching the cerebrum
● Functional importance:
○ Crucial for control of movement, balance, and posture
○ Enables precise movement with economy of effort
● Anatomical features:
○ Consists of paired hemispheres
○ United by a midline structure: the vermis (Latin: "worm")
○ The falx cerebelli (a small, incomplete partition of dura mater) lies between the
cerebellar hemispheres posteriorly
Surfaces of the Cerebellum
1. Superior surface
○ Located directly under the tentorium cerebelli
○ The superior vermis is a raised ridge along the midline
○ The primary fissure (V-shaped) passes across the superior surface
○ The primary fissure demarcates the anterior lobe from the posterior lobe
○ Flanked by the cerebellar hemispheres
2. Inferior surface
○ Lies on the squamous part of the occipital bone
○ The inferior vermis runs along the midline in a furrow called the vallecula
(Latin: "little valley")
○ The uvula of the vermis is partly covered by the cerebellar tonsils (on the
hemispheres)
○ The dorsolateral fissure runs between the nodule and uvula, separating the
flocculonodular lobe from the posterior lobe
○ The horizontal fissure crosses the posterior lobe at the border between superior
and inferior surfaces
,Vermis of the Cerebellum
● Divided into two parts:
1. Inferior vermis
■ Located along the midline on the inferior surface in the vallecula
■ Separated from the cerebellar hemispheres
■ External features from ventral to dorsal:
■ Nodule ("little knot")
■ Uvula ("little grape")
■ Pyramid
■ Tuber ("knob")
2. Superior vermis
■ A slightly raised median ridge on the superior surface
■ Merges laterally with cerebellar hemispheres
■ Anteriorly, contains a small flattened region called the lingula ("little
tongue")
■ Located between the superior cerebellar peduncles
■ Fused to the superior medullary velum in the roof of the fourth
ventricle
■ Subdivisions from ventral to dorsal:
■ Central lobule
■ Culmen ("summit")
■ Declive ("downward slope")
■ Folium ("leaf")
Cerebellar Lobes and Major Fissures
● Dorsolateral fissure:
○ Divides the cerebellum into:
■ Flocculonodular lobe
■ Corpus cerebelli
○ Located on the inferior surface near the anterior cerebellar notch
○ The flocculus ("little tuft") is lateral to the nodule on each side
● Primary fissure:
○ Divides the corpus cerebelli into:
■ Anterior lobe
■ Posterior (middle) lobe
○ V-shaped
○ Seen on the superior surface
,Cerebellar Peduncles
● Function: Connect the cerebellum to the brainstem
● Three pairs:
1. Superior cerebellar peduncle: connects to midbrain
2. Middle cerebellar peduncle: connects to pons
3. Inferior cerebellar peduncle: connects to medulla
● Composed of afferent and efferent fibres to and from the cerebellum
● Attachment: Attached in the interval between the flocculonodular lobe and the
anterior lobe
Anterior Cerebellar Notch and Roof of the Fourth Ventricle
● Anterior cerebellar notch:
○ Hollowed region accommodating the brainstem
○ Lies dorsal to the pons and medulla
○ Forms part of the roof of the fourth ventricle
○ Point of attachment for the cerebellar peduncles
● Roof of the fourth ventricle:
○ Shaped like a tent
○ Rostral part: thin sheet of pia mater and ependyma between the superior
cerebellar peduncles
■ Called the superior medullary velum ("veil")
■ Fused posteriorly to the lingula of the superior vermis
○ Caudal part: another thin sheet of pia mater and ependyma
■ Called the inferior medullary velum
General Cerebellar Features
● Cerebellum (L. "little brain") lies in the posterior cranial fossa.
● Attached to the dorsal aspect of the brainstem.
● Separated from the cerebrum by the tentorium cerebelli (dural fold).
● At birth: cerebellum is 1/20 the size of cerebrum; in adult: 1/8.
● Surface is highly convoluted with fissures (sulci) and folia (L. "leaves").
● Folia run mostly transversely and increase the surface area extensively.
● Critical for control of movement, balance, posture and enabling precise, economical
motion.
● Consists of paired hemispheres united by the vermis (L. "worm").
● Small incomplete dural partition posteriorly: falx cerebelli.
, Cerebellar Lobes and Fissures
● Divided into:
○ Anterior lobe
○ Posterior (middle) lobe
○ Flocculonodular lobe
● Dorsolateral fissure:
○ Separates flocculonodular lobe from the corpus cerebelli (anterior + posterior
lobes).
○ Seen on inferior surface, near anterior cerebellar notch.
○ Flocculus (L. "little tuft") on either side of nodule of the vermis.
● Primary fissure:
○ V-shaped
○ Divides anterior and posterior lobes of the corpus cerebelli
○ Seen on the superior surface
● Horizontal fissure:
○ Passes across posterior lobe
○ Marks the border between superior and inferior cerebellar surfaces
Vermis
● Midline cerebellar structure
● Divided into:
○ Inferior vermis:
■ Lies in the vallecula (L. "little valley") on the inferior surface.
■ Well delineated from hemispheres.
■ Structures (ventral to dorsal): nodule (L. "little knot"), uvula (L. "little
grape"), pyramid, tuber (L. "knob").
○ Superior vermis:
■ Slightly raised ridge on superior cerebellum.
■ Linguia (L. "little tongue"): anterior, between superior cerebellar
peduncles, fused to superior medullary velum.
■ Other subdivisions (ventral to dorsal): central lobule, culmen (L.
"summit"), declive (L. "downward slope"), folium (L. "leaf").
Cerebellar Surfaces
● Superior surface:
○ Located below tentorium cerebelli.
○ Superior vermis visible as midline ridge.
○ Primary fissure passes across it.
○ Divides anterior from posterior lobes.
● Inferior surface:
○ Lies on squamous occipital bone.
Cerebellum – General Features
● Terminology: Cerebellum (Latin: "little brain")
● Location: Situated in the posterior cranial fossa
● Attachment: Connected to the dorsal aspect of the brainstem
● Separation: Separated from the cerebrum superiorly by the tentorium cerebelli (a
partition of dura mater)
● Growth: At birth, the cerebellum is 1/20th the size of the cerebrum; in adulthood, it is
1/8th the size
● Surface characteristics:
○ Highly convoluted with numerous fissures (sulci)
○ Narrow folds called folia (Latin: "leaves") which are mostly transverse
○ Folia increase surface area significantly, almost matching the cerebrum
● Functional importance:
○ Crucial for control of movement, balance, and posture
○ Enables precise movement with economy of effort
● Anatomical features:
○ Consists of paired hemispheres
○ United by a midline structure: the vermis (Latin: "worm")
○ The falx cerebelli (a small, incomplete partition of dura mater) lies between the
cerebellar hemispheres posteriorly
Surfaces of the Cerebellum
1. Superior surface
○ Located directly under the tentorium cerebelli
○ The superior vermis is a raised ridge along the midline
○ The primary fissure (V-shaped) passes across the superior surface
○ The primary fissure demarcates the anterior lobe from the posterior lobe
○ Flanked by the cerebellar hemispheres
2. Inferior surface
○ Lies on the squamous part of the occipital bone
○ The inferior vermis runs along the midline in a furrow called the vallecula
(Latin: "little valley")
○ The uvula of the vermis is partly covered by the cerebellar tonsils (on the
hemispheres)
○ The dorsolateral fissure runs between the nodule and uvula, separating the
flocculonodular lobe from the posterior lobe
○ The horizontal fissure crosses the posterior lobe at the border between superior
and inferior surfaces
,Vermis of the Cerebellum
● Divided into two parts:
1. Inferior vermis
■ Located along the midline on the inferior surface in the vallecula
■ Separated from the cerebellar hemispheres
■ External features from ventral to dorsal:
■ Nodule ("little knot")
■ Uvula ("little grape")
■ Pyramid
■ Tuber ("knob")
2. Superior vermis
■ A slightly raised median ridge on the superior surface
■ Merges laterally with cerebellar hemispheres
■ Anteriorly, contains a small flattened region called the lingula ("little
tongue")
■ Located between the superior cerebellar peduncles
■ Fused to the superior medullary velum in the roof of the fourth
ventricle
■ Subdivisions from ventral to dorsal:
■ Central lobule
■ Culmen ("summit")
■ Declive ("downward slope")
■ Folium ("leaf")
Cerebellar Lobes and Major Fissures
● Dorsolateral fissure:
○ Divides the cerebellum into:
■ Flocculonodular lobe
■ Corpus cerebelli
○ Located on the inferior surface near the anterior cerebellar notch
○ The flocculus ("little tuft") is lateral to the nodule on each side
● Primary fissure:
○ Divides the corpus cerebelli into:
■ Anterior lobe
■ Posterior (middle) lobe
○ V-shaped
○ Seen on the superior surface
,Cerebellar Peduncles
● Function: Connect the cerebellum to the brainstem
● Three pairs:
1. Superior cerebellar peduncle: connects to midbrain
2. Middle cerebellar peduncle: connects to pons
3. Inferior cerebellar peduncle: connects to medulla
● Composed of afferent and efferent fibres to and from the cerebellum
● Attachment: Attached in the interval between the flocculonodular lobe and the
anterior lobe
Anterior Cerebellar Notch and Roof of the Fourth Ventricle
● Anterior cerebellar notch:
○ Hollowed region accommodating the brainstem
○ Lies dorsal to the pons and medulla
○ Forms part of the roof of the fourth ventricle
○ Point of attachment for the cerebellar peduncles
● Roof of the fourth ventricle:
○ Shaped like a tent
○ Rostral part: thin sheet of pia mater and ependyma between the superior
cerebellar peduncles
■ Called the superior medullary velum ("veil")
■ Fused posteriorly to the lingula of the superior vermis
○ Caudal part: another thin sheet of pia mater and ependyma
■ Called the inferior medullary velum
General Cerebellar Features
● Cerebellum (L. "little brain") lies in the posterior cranial fossa.
● Attached to the dorsal aspect of the brainstem.
● Separated from the cerebrum by the tentorium cerebelli (dural fold).
● At birth: cerebellum is 1/20 the size of cerebrum; in adult: 1/8.
● Surface is highly convoluted with fissures (sulci) and folia (L. "leaves").
● Folia run mostly transversely and increase the surface area extensively.
● Critical for control of movement, balance, posture and enabling precise, economical
motion.
● Consists of paired hemispheres united by the vermis (L. "worm").
● Small incomplete dural partition posteriorly: falx cerebelli.
, Cerebellar Lobes and Fissures
● Divided into:
○ Anterior lobe
○ Posterior (middle) lobe
○ Flocculonodular lobe
● Dorsolateral fissure:
○ Separates flocculonodular lobe from the corpus cerebelli (anterior + posterior
lobes).
○ Seen on inferior surface, near anterior cerebellar notch.
○ Flocculus (L. "little tuft") on either side of nodule of the vermis.
● Primary fissure:
○ V-shaped
○ Divides anterior and posterior lobes of the corpus cerebelli
○ Seen on the superior surface
● Horizontal fissure:
○ Passes across posterior lobe
○ Marks the border between superior and inferior cerebellar surfaces
Vermis
● Midline cerebellar structure
● Divided into:
○ Inferior vermis:
■ Lies in the vallecula (L. "little valley") on the inferior surface.
■ Well delineated from hemispheres.
■ Structures (ventral to dorsal): nodule (L. "little knot"), uvula (L. "little
grape"), pyramid, tuber (L. "knob").
○ Superior vermis:
■ Slightly raised ridge on superior cerebellum.
■ Linguia (L. "little tongue"): anterior, between superior cerebellar
peduncles, fused to superior medullary velum.
■ Other subdivisions (ventral to dorsal): central lobule, culmen (L.
"summit"), declive (L. "downward slope"), folium (L. "leaf").
Cerebellar Surfaces
● Superior surface:
○ Located below tentorium cerebelli.
○ Superior vermis visible as midline ridge.
○ Primary fissure passes across it.
○ Divides anterior from posterior lobes.
● Inferior surface:
○ Lies on squamous occipital bone.
