The Cerebellum

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

Lobs Two deep fissures Three lobs Primary fissure Posterolateral fissure Three lobs Flocculonodular lobe 叶 flocculus and nodule Anterior lobe Posterior lobe Corpus of cerebellar

Internal structures Fastigial nucleus Cerebellar cortex Globose nucleus Dentate nucleus Emboliform nucleus medullary center

Connections and function of cerebellum Vestibulocerebellum Function: involved in eye movements and maintain balance

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

Connections and function of cerebellum Cerebrocerebellum Function: participates in planning movements

The Diencephalon

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 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 Floor－hypothalamic sulcus

Three nuclear group－divided by internal medullary lamina Anterior nuclear group Medial nuclear group Lateral nuclear group internal medullary lamina Med. nuclear group Dorsal tier Ant. nuclear group Pulvinar Ventral anterior Medial geniculate body (MGN) Ventral intermediate Ventral posterior nucleus (VP) Lateral geniculate body (LGN) Ventral posterolateral (VPL) Ventral posteromedial (VPM )

Subdivision Principal Nuclei Common abbreviation Ant. nuclear group Med. nuclear group Lat. nuclear group Dorsal tier Lateral dorsal LD Lateral posterior LP Pulvinar Ventral tier Ventral anterior VA Ventral intermediate VI Ventral posterior VP Ventral posterolateral VPL Ventral posteromedial VPM

Special relay nuclei Vent. anterior nucleus (VA) Vent. intermediate nucleus (VI) Receiving dentate nucleus, globus pallidus and substantia nigra to motor cortex Vent. posteromedial nucleus (VPM) －receives trigeminal lemniscus and teste fibers Vent. posterolateral nucleus (VPL) －receives medial lemniscus and spinal lemniscus Projects to first somatic sensory area via central thalamic radiation

Metathalamus后丘脑 Metathalamus Lateral geniculate body (LGN) Medial geniculate body (MGN) Metathalamus

Metathalamus Medial geniculate body (MGN) Relay station of audition Receive fibers from inferior colliculus Projects to auditory area via acoustic radiation Lateral geniculate body (LGN) Relay station of vision Receive fibers from optic tract Projects to visual area via optic radiation

Hypothalamus Position－lies ventral to thalamus Boundaries 视上部位于视交叉上方， Superiorly: hypothalamic sulcus Inferiorly: optic chiasma tuber cinereum Infundibulum mamillary body Anterior: lamina terminalis Posterior: continues with midbrain tegmentum 视上部位于视交叉上方， 由视上核和室旁核所组成； 结节部位于漏斗的后方； 乳头部位于乳头体。

Subthalamus Transition zone between diencephalons and tegmentum of midbrain Contain subthalamic nucleus, parts of red nucleus and substantia nigra 内含底丘脑核，与黑质、红核、苍白球有密切联系，属锥体外系的 重要结构。人类一侧底丘脑核受损，可产生对侧肢体，尤其上肢较为显著的、不自主的舞蹈样动作，成半身舞蹈病或半身颤搐(tarantism)。

Hypothalamus --connection Supraoptic nucleus →supraoptic nucleus (ADH) →supraopticohypophyseal tract →posterior lobe of hypophysis Paraventricular nucleus → paraventicular nucleus (oxytocin) →paraventriculohypophyseal tract→posterior lobe of hypophysis

Hypothalamus Function Regulates functions of neuroendocrine system Autonomic nervous system

Third ventricle Communication Position: a narrow ventricle cleft lies within diencephalons Boundaries Roof: choroids plexus Floor: optic chiasma, tuber cinereum, infundibulum and mamillary body Anterior: lamina terminalis Posterior: continuous with mesencephalic aqueduct Lateral wall: dorsal thalamus and hypothalamus Communication Third ventricle →mesencephalic aqueduct → fourth ventricle

The Telencephalon

External feature The telencephalon consists of right and left cerebral hemisphere, partially separated by cerebral longitudinal fissure. The cerebral transverse fissure intervenes between the hemispheres and the cerebellum Each hemisphere has three surfaces: superolateral, medial and inferior

Three principal sulci Central sulcus Lateral sulcus Parietooccipital sulcus Central sulcus Parietooccipital sulcus Lateral sulcus

Five lobes Frontal lobe Parietal lobe Temporal lobe Occipital lobe Insular lobe Parietal lobe Insular lobe Frontal lobe Occipital lobe Temporal lobe

Hippocampus Hippocampal formation Dentate gyrus

Functional location of cerebral cortex

First somatic motor area Position: located in precentral gyrus and anterior portion of paracentral lobule

First somatic motor area Characters Representation is inverted, but head and face are upright A body part is represented by a cortical area proportional to its use rather than its size Receiving fibers from postcentral gyrus, VA, VL and VPL, sending out fibers to form pyramidal tract, controlling voluntary movements

First somatic sensory area Position－lies in postcentral gyrus and posterior portion of paracentral lobule

First somatic sensory area Characters Sensory representation, like motor area, is crossed and inverted Receiving and interpret sensation from opposite side of body

Auditory area Located in transverse temporal gyri Receive auditory information from both ears

Visual area Lie on either side of calcarine sulcus in medial surface of occipital lobe Visual cortex of one hemisphere receives impression from temporal part of retina of same side and nasal part of opposite side Lesions of visual cortex produce contralateral homonymous visual field defections

Vestibular area: located in front of superior temporal gyrus Olfactory area : located near the uncus Taste area : located at frontal operculum

Language area It is dominant in left hemisphere in right-handed person Motor speech area Located in posterior portion of inferior frontal gyrus Damage: motor aphasia Writing area Located in posterior portion of middle frontal gyrus Damage: agraphia Auditory speech area Located in posterior portion of superior temporal gyrus Lesion: sensory aphasia Visual speech area Located in angular gyrus Lesion: alexia

Internal structures Lateral ventricle Position: located in cerebral hemispheres Four parts Central part: lies in parietal lobe Anterior horn: extends into frontal lobe Posterior horn extend into occipital lobe Inferior horn: extend into temporal lobe

Communication lateral ventricle → interventricular foramen → third ventricle

Basal nuclei Corpus striatum Amygdaloid body Lentiform nucleus Caudate nucleus Claustrum Amygdaloid body Globus pallidus －paleostriatum putamen Neostriatum

White matter Association fibers Run between gyri within the same hemisphere Cerebral arcuate fibers Superior longitudinal fasciculi Inferior longitudinal fasciculi Uncinate fasciculus Cingulum

Commissural fibers － run between left and right hemisphere Corpus callosum: rostrum, genu, trunk, splenium Anterior commissure Fornix and commissure of fornix

Projection fibers: connect cortex with lower part of brain and spinal cord and they include both ascending and descending fibers Internal capsule Position: a thick lamina of white matter lying between caudate nucleus, thalamus and lentiform nucleus

Three parts Anterior limb of internal capsule Genu of internal capsule Lies between caudate nucleus and lentiform nucleus Containing frontopontine tract and anterior thalamic radiation Genu of internal capsule Is angle at which anterior and posterior limbs meet Containing corticonuclear tract Posterior limb of internal capsule Lies between thalamus and lentiform nucleus Contain corticospinal tract, corticorubral tract, central thalamic radiation, parieto-occipito-temporo-pontine tract, acoustic radiation and optic radiation

Anterior thalamic radiation Head of caudate nucleus Frontopontine tract Corticonuclear tract Lentiform nucleus Corticorubral tract Corticospinal tract Parieto-occipito- temporo-pontine tract Dorsal thalamus Central thalamic radiation Acoustic radiation Medial geniculate body Optic radiation Lateral geniculate body

Limbic system Composition Limbic lobe: includes septal area, cingulated gyrus, parahippocampal gyrus, hippocampus, dentate gyrus, temporal pole, anterior part of insular lobe and so on Associated subcortical nuclei: amygdaloid body, septal nuclei, hypothalamus, epithalamus, anterior nucleus group of thalamus, tegmentum of midbrain Function: concerned with visceral activities, olfaction, emotion and memory, so this system is called ‘visceral brain’