Chapter15-2-2小腦和間腦

1、Department of Anatomy1Chapter 15 Chapter 15 The Central Nervous SystemThe Central Nervous System The Nervous The Nervous SystemSystem Department of Anatomy2Section 2 The brain Position:Lies above and behind the medullar and pons and occupies posterior cranial fossaII. The cerebellum CerebellumDepart

2、ment of Anatomy3The cerebellum consists of a midline portionthe vermistwo lateral lobes hemispheres I ) The external features Department of Anatomy4I ) The external features The cerebellar tonsils-two elevated masses on the inferior surface of the hemisphereal portionCerebellar tonsilCerebellar tons

3、ilInferior surfaceInferior surfacebehind the flocculonodular lobe and nearby the foramen magnumDepartment of Anatomy5On the superior surface of the cerebellum two fissures can be identified I ) The external features Horizontal fissure Primary fissure Department of Anatomy6I ) The external features O

4、n the inferior surface the posterolateral fissures are found Posterolateral fissureDepartment of Anatomy7I ) The external features i. The flocculonodular lobe ii. The anterior lobe iii. The posterior lobe Anterior lobeAnterior lobePosterior lobePosterior lobePrimary fissurePrimary fissureI ) The ext

5、ernal features Department of Anatomy9II) The internal structure i. Cerebellar cortex The cerebellar cortex consists of three layers: outer molecular layer; the purkinje cell layer; the granular layer; an inner layer composed mainly of small granule cells. The cerebellar cortex is arranged as a highl

6、y ordered array, consisting of five primary cell types. Department of Anatomy10II) The internal structure ii. White matter The cerebellum is connected to the other parts of the brain by three large bundles of projection fibers, viz.to the cerebrum by the superior peduncle to the pons by the middle p

7、eduncleto the medulla oblongata by the inferiorpedunclethree peduncleInferior cerebellar peduncle Connect with medulla and with spinal cord, contain both afferent and efferent fibers Middle cerebellar peduncle Connect with pons, contain afferent fibersSuperior cerebellar peduncle Connect with midbra

8、in, contain mostly efferent fibersThree pedunclesDepartment of Anatomy12II) The internal structure The cerebellar nuclei in the cerebellum are four in number on either side Cerebellar cortexCerebellar cortexDentate nucleusDentate nucleusmedullary centermedullary centerEmboliform nucleusEmboliform nu

9、cleusGlobose nucleusGlobose nucleusFastigial nucleusFastigial nucleusDepartment of Anatomy13The fourth ventricle is situated in front of the cerebellum and behind the pons and upper half of the medulla oblongata II) The internal structure The fourth ventricleDepartment of Anatomy14III) Function of c

10、erebullum VestibulocerebellumArchicerebellum Flocculonodular lobeSpinocerebellumPaleocerebellum Vermis and the anterior portions of the hemispheres CerebrocerebellumNeocerebellum Lateral zoneDepartment of Anatomy15III) Function VestibulocerebellumConnections Afferents: Receive input from vestibular

11、nuclei and primary vestibular Efferents: Projects to the vestibular nucleus vestibulospinal tract and medial longitudinal fasciculus motor neurons of anterior hornFunction: Involved in eye movements and maintain balance Department of Anatomy16III) Function CerebrocerebellumConnection CerebrumFunctio

12、n: Participates in planning movementsDepartment of Anatomy17III. The diencephalons Position: Lies between midbrain and cerebrum, almost entirely surrounded by cerebral hemisphereDepartment of Anatomy18III. The Diencephalons SubdivisionDoral thalamusMetathalamus Epithalamus Subthalamus Hypothalamus D

13、epartment of Anatomy19III. The Diencephalons I ) The dorsal thalamus (thalamus) i. Landmarks A large egg-shaped nucleus mass, Anterior end - anterior thalamic tubercle, Posterior end - pulvinarRight and left portion of thalamus are joined by interthalamic adhesion FloorHypothalamic sulcusDepartment

14、of Anatomy20The dorsal thalamus (thalamus) Department of Anatomy22ii. The thalamic nuclei Three nuclear groupDivided by internal medullary laminaAnterior nuclear group Medial nuclear group Lateral nuclear group I ) The dorsal thalamus (thalamus) Department of Anatomy23Medial nuclear group Anterior n

15、uclear group Dorsal tier Internal medullary laminaVentral anterior Ventral intermediate Ventral posterolateral (VPL) Ventral posteromedial (VPM ) Pulvinar Medial geniculate body Lateral geniculate body Ventral posterior nucleus (VP)The dorsal thalamus (thalamus) Department of Anatomy24iii. Functiona

16、l divisions Nonspecific nucleiReceive afferents from Dinencephalon and reticular formation of brain stem, project mainly to hypothalamus and corpus striatumMidline nucleus group Intralaminar nuclear groupThalamic reticular nucleusThe dorsal thalamus (thalamus) Department of Anatomy25iii. Functional

17、divisions Association nucleiReceive input from many converging and in turn project widely to the association areas of cerebral cortexAnterior nuclear group Medial nuclear groupDorsal tier of lateral nuclear groupThe dorsal thalamus (thalamus) Department of Anatomy26iii. Functional divisions Special

18、relay nucleiVentral anterior nucleus (VA) Ventral intermediate nucleus (VI) Receiving dentate nucleus, globus pallidus and substantia nigra to motor cortexVentral posteromedial nucleus (VPM) Receives trigeminal lemniscus and taste fibers The dorsal thalamus (thalamus) Department of Anatomy27iii. Fun

19、ctional divisions Ventral posterolateral nucleus (VPL) Receives medial lemniscus spinal lemniscusProjects to first somatic sensory area via central thalamic radiationThe dorsal thalamus (thalamus) Department of Anatomy28iv. Clinical correlations The thalamic syndrome is characterized by immediate he

20、mianesthesia, with the threshold of sensitivity to pinprick, heat, and cold rising later. The syndrome usually appear during recovery from a thalamic infarct The dorsal thalamus (thalamus) Department of Anatomy29II) The epithalamus Includes Thalamic medullary stria Habenular trigoneHabenular commiss

21、ure Pineal body Posterior commissure Department of Anatomy30III) The subthalamus The subthalamus is the zone of brain tissue that lies between the dorsal thalamus and the tegmentum of the midbrain Department of Anatomy31IV )The metathalamus Lateral geniculate body Medial geniculate bodyDepartment of

22、 Anatomy32Medial geniculate body Relay station of auditionReceive fibers from inferior colliculusProjects to auditory area via acoustic radiation Lateral geniculate body Relay station of visionReceive fibers from optic tractProjects to visual area via optic radiation IV ) The metathalamus Department

23、 of Anatomy33V ) The hypothalamus i. Landmarks Superiorly: hypothalamic sulcusInferiorly: Optic chiasma Tuber cinereum Infundibulum Mamillary body Anterior: lamina terminalis Posterior: continues with midbrain tegmentumDepartment of Anatomy34SubdivisionsPreoptic region Supraoptic region Tuberal regi

24、on Mamillary region V ) The hypothalamus V ) The hypothalamus Supraoptic region Supraoptic nucleus Produce antidiuretic hormone (ADH， vasopressin )Paraventricular nucleus Produce oxytocin Tuberal region Infundibular nucleus Ventromedial nucleus Dorsomedial nucleus Mamillary region Mamillary nucleus

25、Posterior hypothalamic nucleus Important nucleiDepartment of Anatomy36V ) The hypothalamus ii. Afferent connections Afferent and emotional inputs from the prefrontal cortex reach the hypothalamus via a polysynaptic pathway. In addition, visceral information from the vagal sensory nuclei, gustatory m

26、essages from the nucleus solitarius, and somatic afferent messages from the genitalia and nipples are relayed to the hypothalamus Department of Anatomy37Department of Anatomy38V ) The hypothalamus iii. Efferent connections There are rich connections between the hypothalamus and the pituitary gland. Neurons in the supraoptic and paraventricular nuclei send axons, via the hypothalamohypophyseal