The Cerebellum 小脑,Department of Human Anatomy, College of Basic Medicine, Zhengzhou University,雷留根,Position,Lies above and behind the medullar and pons and occupies posterior cranial fossa,Cerebellum,External features,Consists of two cerebellar hemisphere united in the midline by the vermis,External features,Three peduncles Inferior cerebellar peduncle 小脑下脚 connect with medulla and with spinal cord, contain both afferent and efferent fibers Middle cerebellar peduncle 小脑中脚connect with pons, contain afferent fibers Superior cerebellar peduncle 小脑上脚connect with midbrain, contain mostly efferent fibers,External features,Tonsil of cerebellum 小脑扁桃体 two elevated masses on inferior surface of hemispheral portion just nearby foramen magnum,Lobs,Two deep fissures Primary fissure 原裂 Posterolateral fissure 后外侧裂 Three lobs Flocculonodular lobe 绒球小结叶 flocculus and nodule Anterior lobe Posterior lobe,Corpus of cerebellar 小脑体,Lobs,Primary fissure,Posterolateral fissure,Flocculonodular lobe,Anterior lobe,Posterior lobe,corpus of cerebellar,Internal structures,Gray matter Cerebellar cortex Cerebellar nuclei Dentate nucleus 齿状核 Fastigial nucleus 顶核 Interposed nucleus 中间核 Emboliform nucleus 栓状核 Globose nucleus球状核 White mattermedullary center 髓体,Internal structures,Cerebellar cortex,Dentate nucleus,Fastigial nucleus,Globose nucleus,Emboliform nucleus,medullary center,Three functional divisions,Vestibulocerebellum 前庭小脑 Archicerebellum 原小脑 Flocculonodular lobe Spinocerebellum 脊髓小脑 Paleocerebellum旧小脑 Vermis and intermediate zone Cerebrocerebellum 大脑小脑 Neocerebellum 新小脑 Lateral zone,Flocculonodular lobe,Vermis,Intermediate zone,Lateral zone,Connections and function of cerebellum,Vestibulocerebellum Connections Afferents: receive input from vestibular nuclei and primary vestibular Efferents: projects to the vestibular nucleus vestibulospinal tract and medial longitudinal fasciculus motor neurons of anterior horn Function: involved in eye movements and maintain balance,Connections and function of cerebellum,Spinocerebellum Connnection Afferents: receive somatic sensory information via spinocerebellar tracts,Efferents: Vermis projects to the fastigial nucleus vestibular nuclei and reticular formation vestibulospinal tract and reticulospinal tract motor neurons of anterior horn Intermediate zone projects to the interposed nuclei Contralateral red nucleus rubrospinal tract motor neurons of anterior hornContralateral VI cerebral cortex coticospinal tractmotor neurons of anterior hornFunction: play an important role in control of muscle tone and coordination of muscle movement on the same side of the body,Connections and function of cerebellum,Cerebrocerebellum Connection Afferents: receives input from the cerebral cortex via a relay in pontine nuclei Efferents: projects to dentate nucleus VI primary motor cortex corticospinal tract motor neurons of anterior horn Function: participates in planning movements,The Diencephalon 间脑,Position,Position: Lies between midbrian and cerebrum, almost entirely surrounded by cerebral hemisphere,Subdivision,Doral thalamus 背侧丘脑 Metathalamus 后丘脑 Epithalamus 上丘脑 Subthalamus 底丘脑 Hypothalamus 下丘脑,Dorsal thalamus 背侧丘脑,External features A large egg-shaped nucleus mass, Anterior end called anterior thalamic tubercle, Posterior end called pulvinar Right and left portion of thalamus are joined by interthalamic adhesion Floorhypothalamic sulcus,Classification of nuclei of dorsal thalamus,Three nuclear groupdivided by internal medullary lamina （内髓板） Anterior nuclear group 前核群 Medial nuclear group 内侧核群 Lateral nuclear group 外侧核群,Med. nuclear group,Ant. nuclear group,Dorsal tier,internal medullary lamina,Ventral anterior,Ventral intermediate,Ventral posterolateral (VPL),Ventral posteromedial (VPM ),Pulvinar,Medial geniculate body (MGN),Lateral geniculate body (LGN),Ventral posterior nucleus (VP),Functional subdivision,Nonspecific relay nuclei非特异性中继核团receive afferents from rhinencephalon and reticular formation of brain stem, project mainly to hypothalamus and corpus striatum Midline nucleus group Intralaminar nuclear group Thalamic reticular nucleus Association nuclei 联络核团receive input from many converging sours and in turn project widely to the association areas of cerebral cortex Anterior nuclear group Medial nuclear group Dorsal tier of lateral nuclear group,Special relay nuclei 特异性中继核团 Vent. anterior nucleus (VA) 腹前核 Vent. intermediate nucleus (VI) 腹中间核 Receiving dentate nucleus, globus pallidus and substantia nigra to motor cortex Vent. posteromedial nucleus (VPM) 腹后内侧核receives trigeminal lemniscus and taste fibers Vent. posterolateral nucleus (VPL) 腹后外侧核receives medial lemniscus and spinal lemniscusProjects to first somatic sensory area via central thalamic radiation,