Gracile lobule
Lobulus gracilis
A slender lobule on the inferior surface of each cerebellar hemisphere, lying between the inferior semilunar lobule and the biventral lobule.
At a glance
- English
- Gracile lobule
- Latin (TA2)
- Lobulus gracilis
- System
- Brain and spinal cord
- Region
- Head
- Side
- Paired, left and right
About the gracile lobule
The gracile lobule is one of the lobules of the cerebellar hemisphere. Its name means slender, and it is a narrow band of a few folia on the underside of the cerebellum. In modern terminology it is the same as the paramedian lobule, and in Larsell's numbered scheme it is hemispheric lobule H VIIB.
It lies on the inferior surface, behind and above the biventral lobule and below the inferior semilunar lobule, with which it is often grouped. Its folia run roughly across the hemisphere and, towards the midline, it is continuous with the lower part of the tuber of the vermis. Behind it, the gracile lobule is separated from the inferior semilunar lobule by a shallow fissure, and in front the prepyramidal (prebiventral) fissure separates it from the biventral lobule. Some descriptions do not separate it at all and count its folia as the lower part of the inferior semilunar lobule.
Like the rest of the lateral hemisphere, its cortex has molecular, Purkinje cell and granular layers. The lateral hemispheres receive input mostly from the cerebral cortex by way of the pontine nuclei and the middle cerebellar peduncle, and their Purkinje cells project to the dentate nucleus, which sends fibres through the superior cerebellar peduncle to the opposite thalamus and red nucleus. Through this loop the hemispheres help to plan and coordinate skilled movements of the limbs on the same side.
Lesions of the cerebellar hemisphere give signs on the same side of the body: an intention tremor, past-pointing, poor rapid alternating movements and a tendency to fall towards that side.
Function and supply
- Function
- Part of the cerebellar hemisphere, taking part in the cortico-ponto-cerebellar loop that coordinates skilled movements of the limbs on the same side.
- Blood supply
- Branches of the posterior inferior cerebellar artery on the inferior surface of the hemisphere.
Anthromica
See the gracile lobule 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.
