Chapter 12 Cerebellum BASIC ANATOMY The deep cerebellar nuclei The functional loops The cerebrocerebellum The vestibulocerebellum The spinocerebellum The olivocerebellum Peduncles Afferent connections Efferent connections The intrinsic circuitry within the cerebellum FUNCTION OF THE CEREBELLUM Cerebrocerebellum Vestibulocerebellum Spinocerebellum The detail Basic anatomy The cerebellum, often refered to as the ‘little brain’, makes up only 10% of the total brain volume but contains more than 50% of the total number of neurons. It is composed of an outer layered cortical region and an inner subcortical mass of cells which form the deep cerebellar nuclei (DCN). The cerebellum is topographically arranged and has ipsilateral control of movement, that is, the left hemisphere of the cerebellum controls the left side of the body. The cerebellum is divided by two deep transverse fissures into three lobes, anterior, posterior and flocculonodular lobe. On the upper surface there are three functional regions separated anatomically by two longtitudinal stripes. The central vermis (medial zone) and two paravermal regions or hemispheres. The paravermal regions are divided into the lateral and intermediate zones. The deep cerebellar nuclei There are four deep cerebellar nuclei (DCN): • Fastigial • Interposed – globose and emboliform • Dentate All output from the cerebellum leaves via the DCN, with the exception of output to the vestibular nuclei which has a direct connection. Afferent pathways also send collaterals that synapse on neurons in the DCN. The functional loops Based on its function, the cerebellum can be broadly divided into four loops: The cerebrocerebellum This incorporates a loop between the cerebral cortex and the cerebellum. It is located in the lateral zone of the paravermal regions and is strongly connected with the dentate nucleus. The vestibulocerebellum This incorporates a loop between the vestibular system and the cerebellum. It roughly corresponds to the flocculonodular lobe and has no connection to the DCN. The spinocerebellum This incorporates a loop between the spinal cord and the cerebellum. It extends through the central vermis (medial zone) linked to the fastigial nucleus and the intermediate zone of the paravermal regions connected to the interposed nucleus. The olivocerebellum This incorporates a loop between the inferior olivary nucleus (in the medulla oblongata) and the cerebellum. It has strong links to the DCN. Peduncles Only gold members can continue reading. Log In or Register to continue Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window) Related Related posts: Motor neuron disease The ascending tracts Thalamus and limbic system Myotomes Postural alignment Strength Stay updated, free articles. Join our Telegram channel Join Tags: Neurological Assessment A Clinicians Guide Jun 4, 2016 | Posted by admin in NEUROLOGY | Comments Off on Cerebellum Full access? Get Clinical Tree
Chapter 12 Cerebellum BASIC ANATOMY The deep cerebellar nuclei The functional loops The cerebrocerebellum The vestibulocerebellum The spinocerebellum The olivocerebellum Peduncles Afferent connections Efferent connections The intrinsic circuitry within the cerebellum FUNCTION OF THE CEREBELLUM Cerebrocerebellum Vestibulocerebellum Spinocerebellum The detail Basic anatomy The cerebellum, often refered to as the ‘little brain’, makes up only 10% of the total brain volume but contains more than 50% of the total number of neurons. It is composed of an outer layered cortical region and an inner subcortical mass of cells which form the deep cerebellar nuclei (DCN). The cerebellum is topographically arranged and has ipsilateral control of movement, that is, the left hemisphere of the cerebellum controls the left side of the body. The cerebellum is divided by two deep transverse fissures into three lobes, anterior, posterior and flocculonodular lobe. On the upper surface there are three functional regions separated anatomically by two longtitudinal stripes. The central vermis (medial zone) and two paravermal regions or hemispheres. The paravermal regions are divided into the lateral and intermediate zones. The deep cerebellar nuclei There are four deep cerebellar nuclei (DCN): • Fastigial • Interposed – globose and emboliform • Dentate All output from the cerebellum leaves via the DCN, with the exception of output to the vestibular nuclei which has a direct connection. Afferent pathways also send collaterals that synapse on neurons in the DCN. The functional loops Based on its function, the cerebellum can be broadly divided into four loops: The cerebrocerebellum This incorporates a loop between the cerebral cortex and the cerebellum. It is located in the lateral zone of the paravermal regions and is strongly connected with the dentate nucleus. The vestibulocerebellum This incorporates a loop between the vestibular system and the cerebellum. It roughly corresponds to the flocculonodular lobe and has no connection to the DCN. The spinocerebellum This incorporates a loop between the spinal cord and the cerebellum. It extends through the central vermis (medial zone) linked to the fastigial nucleus and the intermediate zone of the paravermal regions connected to the interposed nucleus. The olivocerebellum This incorporates a loop between the inferior olivary nucleus (in the medulla oblongata) and the cerebellum. It has strong links to the DCN. Peduncles Only gold members can continue reading. Log In or Register to continue Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window) Related Related posts: Motor neuron disease The ascending tracts Thalamus and limbic system Myotomes Postural alignment Strength Stay updated, free articles. Join our Telegram channel Join Tags: Neurological Assessment A Clinicians Guide Jun 4, 2016 | Posted by admin in NEUROLOGY | Comments Off on Cerebellum Full access? Get Clinical Tree
