Peduncle of flocculus
Pedunculus flocculi
The thin stalk of white matter joining the flocculus on each side of the cerebellum to the nodule of the vermis.
At a glance
- English
- Peduncle of flocculus
- Latin (TA2)
- Pedunculus flocculi
- System
- Brain and spinal cord
- Region
- Head
- Side
- Paired, left and right
About the peduncle of flocculus
The peduncle of the flocculus is a slender band of white matter on the inferior surface of the cerebellum. It runs from the flocculus, a small tuft of folia on each side, medially to the nodule, the lowest part of the inferior vermis. With the flocculus and nodule it makes up the flocculonodular lobe, the oldest part of the cerebellum, which is separated from the rest of the organ by the posterolateral fissure.
The flocculus lies at the cerebellopontine angle, just below and behind the middle cerebellar peduncle, near the lateral recess of the fourth ventricle and close to the roots of the facial and vestibulocochlear nerves. From there the peduncle passes medially along the roof of the fourth ventricle. It is attached to the thin inferior medullary velum, part of the roof of the ventricle, which stretches between the two flocculi and the nodule like a sheet.
Functionally the flocculonodular lobe is the vestibulocerebellum. It receives fibres from the vestibular nerve and vestibular nuclei and sends fibres back to the vestibular nuclei. Through these circuits it keeps the eyes steady while the head moves, holds the gaze fixed on a target and helps keep balance of the trunk. The peduncle carries fibres between the parts of this lobe.
Damage to the flocculonodular region, often from a tumour in the roof of the fourth ventricle in a child, gives an unsteady, wide-based gait and abnormal eye movements such as nystagmus, while the coordination of the limbs may be fairly well kept. The flocculus also matters in surgery of the cerebellopontine angle, where it may cover the nerve roots.
Function and supply
- Function
- Connects the flocculus to the nodule, linking the two halves of the vestibulocerebellum, which controls balance, gaze holding and eye movements during head motion.
- Blood supply
- Mainly the anterior inferior cerebellar artery, with the posterior inferior cerebellar artery supplying the nodule.
Anthromica
See the peduncle of flocculus where it really sits, with every layer of the body around it.
- Every layer, one body. Peel from muscle to bone, nerve, vessel and organ, and turn it any way.
- English and Latin. Every structure named the way your exam names it.
- Quiz until it sticks. Short drills on the structures you keep missing.
Free to start. No card.
