小脑概述.ppt

　　The Cerebellum小 脑

　　lies above and behind the medulla oblongata and pons; occupies posterior cranial fossa

　　Cerebellum

　　Position:

　　External features

　　Three peduncles 三对脚 Inferior cerebellar peduncle 小脑下脚 connect with medulla and spinal cord, contain both afferent and efferent fibers

　　External features

　　Three peduncles 三对脚 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 hemisphere, just nearby foramen magnum

　　Lobes of cerebellum

　　Two deep fissures Primary fissure 原裂 Posterolateral fissure 后外侧裂 Three lobs 1. Flocculonodular lobe绒球小结叶: flocculus 绒球 and nodule 小结 2. Anterior lobe 3. Posterior lobe

　　corpus of cerebellar 小脑体

　　Lobes

　　Primary fissure

　　Posterolateral fissure

　　(Gp:) Flocculonodular lobe 绒球小结叶

　　Anterior lobe

　　Posterior lobe

　　corpus of Cerebellum 小脑体

　　(Gp:) Flocculus 绒球

　　(Gp:) nodule 小结

　　Ⅱ. Internal structures

　　Cerebellar cortex 小脑皮质 Cerebellar nuclei 小脑核

　　Gray matter

　　Dentate nucleus 齿状核 Fastigial nucleus 顶核 Interposed nuclei 中间核 Emboliform nucleus 拴状核 Globose nucleus 球状核

　　Ⅱ. Internal structures

　　Cerebellar cortex

　　Dentate nucleus

　　Fastigial nucleus

　　Globose nucleus

　　Emboliform nucleus

　　medullary center

　　White matter—

　　medullary center小脑髓体

　　Three functional divisions

　　Spinocerebellum 脊髓小脑( paleocerebellum 旧小脑) : vermis and intermediate zone Cerebrocerebellum 大脑小脑(neocerebellum 新小脑): lateral zone Vestibulocerebellum 前庭小脑 ( archicerebellum原小脑): Flocculonodular lobe and vestibular nuclei

　　Flocculonodular lobe

　　vermis

　　intermediate zone

　　lateral zone

　　Middle cerebellar peduncle 小脑中脚

　　is composed of fibres which arises in the opposite side of the pontine nuclei and pass to the erebellum, transmit impulses which reach the the pons from the cerebral cortex.

　　Ⅲ. Connections and peduncles of cerebellum

　　inferior cerebellar peduncle 小脑下脚

　　This peduncle consists mainly of afferent fibres to the cerebellum，inlude posterior spinocerebellar tract; the fibers from the inferior olivary nucleus,

　　Ⅲ. Connections and peduncles of cerebellum

　　the fibers from vestibular nuclei and nerve.

　　It also transmits efferent fibres to the medulla oblongata.

　　superior cerebellar peduncle 小脑上脚

　　This is the principal efferent pathway from the cerebellum, its fibres arises mainly from the dentate nucleus齿状核, and passes anterosuperiorly to the opposite thalamus丘脑 and red nucleus of the midbrain.

　　Ⅲ. Connections and peduncles of cerebellum

　　IV. Connections and function of cerebellum

　　Afferents fibers 传入纤维: receive input from vestibular nuclei and vestibular n..

　　Vestibulocerebellum 前庭小脑

　　Efferents fibers 传出纤维: to the vestibular nucleus → vestibulospinal tract → anterior horn.of spinal cord. → medial longitudinal fasciculus 内侧纵束→ motor nuclei asociated with movement of eyeball。

　　Function: involved in eyeball movements and maintain the balance of the body

　　Afferent fibers: receive somatic sensory information via spinocerebellar tracts.

　　IV. Connections and function of cerebellum

　　Spinocerebellum 脊髓小脑

　　Efferent fibers: to the fastigial nucleus顶核→ vestibular nuclei → vestibulospinal tract → motor neurons of anterior horn

　　IV. Connections and function of cerebellum

　　Efferent fibers: to the interposed nuclei中间核 → ① contralateral red nucleus → rubrospinal tract →motor neurons of anterior horn of spinal cord

　　Spinocerebellum 脊髓小脑

　　② contralateral thalamus对侧丘脑→cerebral cortex大脑皮质

　　IV. Connections and function of cerebellum

　　Spinocerebellum

　　Function: play an important role in control of muscle tone and coordination of muscle movement on the same side of the body

　　Cerebrocerebellum

　　Afferents: receives input from the cerebral cortex via the pontine nuclei middle cerebellar peduncle Efferents: to dentate nucleus 齿状核→ contralateral thalamus → primary motor cortex → corticospinal tract → motor neurons of anterior horn

　　IV. Connections and function of cerebellum

　　Function: coordination of muscle movement of limbs.