大学精品课件：Internal strucuture of cerebrum.ppt

1、Telencephalon (端脑) Cerebrum (大脑),External Features:,The telencephalon consists mainly of two large cerebral hemispheres separated by the longitudinal cerebral fissure, at the bottom of this fissure the corpus callosum crossing between the two hemispheres . The transverse cerebral fissure intervenes

2、between the hemispheres and the cerebellum . There are three demarcating sulci (or fissure )on the surface of the hemisphere: lateral sulcus, parietooccipital sulcus, central sulcus,Lobes of cerebrum:,The hemisphere can be divided by these sulci and an imaginary line into four lobes: frontal lobe, p

3、arietal lobe, temporal lobe, occipital lobe, insula,The sulci and gyri on lat. surface of cerebrum,In the frontal lobe the precentral is parallel with the central sulcus ;these sulci outline the precentral gyrus .The remainder surface of the frontal lobe is divided into superior ,middle ,and inferio

4、r gyri by superior and inferior frontal sulci. In the parietal lobe ,the postcentral sulcus is parallel with the central sulcus ;these sulci bound the postcentral gyrus .The interparietal sulcus divides that part of the surface not occupied by the postcentral gyrus into superior and inferior parieta

5、l lobules .Those portions of the inferior lobule consist of the supramarginal gyrus and the angular gyrus.,The sulci and gyri on lat. surface of cerebrum,In the temporal lobe the superior and inferior temporal sulci divide the lateral surface of the temporal lobe into superior ,middle ,and inferior

6、temporal gyri .The upper surface of the superior temporal gyrus presents two transverse temporal gyri on it .In the occipital lobe ,the sulci and gyri of this lobe are not constant,The sulci and gyri on medial and inferior surface of cerebrum,Cingulated gyrus扣带回 is sepatated from the corpus callosum

7、 (胼胝体) by the callosal sulcus .The cingulate sulcus intervenes between the cingulated gyrus and the extension of the superior frontal gyrus on the medial surface of the hemisphere . The region bounded by the paracentral and marginal sulci is called the paracentral lobule. The calcarine sulcus距状沟 com

8、mences near the occipital pole and runs anteriorly ,joining the parietooccipital sulcus at an acute angle .,The sulci and gyri on medial and inferior surface of cerebrum,On the inferior surface of the hemisphere the posterior part of this gyrus consists of the lingual gyrus(舌回) , the anterior part f

9、orms the parahippocampal gyrus, which hooks sharply backward as the uncus(钩) . On the orbital surface of the frontal lobe ,the olfactory bulb and olfactory tract conceal most of the olfactory sulcus .The gyrus rectus (直回)is medial to the olfactory sulcus ,and the large area lateral to the olfactory

10、sulcus consists of irregular orbital gyri(眶回).,Internal structures of the cerebrum,Each cerebral hemisphere is composed of an outer layer of grey matter, termed the cortex, and an inner mass of white matter, the medullary center .,Within the hemisphere, there are several masses of grey matter known

11、as the basal nuclei and a cavity, the lateral ventricle .,I The functional localization of cerebral cortex,Clinicopathologic studies and animal experiments conducted over more than a century have provided information concerning functional specialization in different regions of the cerebral cortex .,

12、The motor area ( primary motor area ),Location: It is located in the precentral gyrus and the anterior part of the paracentral lobule on the medial surface of the hemisphere .,Characters of the localization:,2. The sensory area ( the somesthetic area ),Location: It occupies the postcentral gyrus on

13、the lateral surface of the hemisphere and the posterior part of the paracentral lobule on the medial surface.,Characters of the localization:,3. The visual area,Location: It surrounds the calcarine sulcus (距状沟) on the medial surface of the occipital lobe.,4. The acoustic area,Location: It is located

14、 in the transverse temporal gyri.,5.The language areas,They are situated in the left hemisphere, with few exceptions, and this hemisphere is therefore the dominant hemisphere as a rule with respect to language.,The motor language area Location: It is located in the post. of inf. frontal gyrus ( Broc

15、as area). The auditory language area Location: It is located in the post. part of sup. temporal gyrus (sup.marginal gyrus).,The visual language area Location: It is located in the angular gyrus. The writing area Location: It is located in the post. part of middle frontal gyrus.,II The internal struc

16、tures of cerebrum,Each cerebral hemisphere includes a large volume of white matter constituting the medullary center, basal nuclei and lat. ventricle,1. The basal nuclei,corpus striatum(纹状体) (caudate nucleus尾状核, lentiform nucleus豆状核), claustrum (屏状核) amygdaloid body(杏仁核)., The corpus striatum It con

17、sists of the caudate nucleus(尾状核) and the lenticular nucleus(豆状核), the latter being divided into the putamen(壳) and the globus pallidus(苍白球).,The caudate nucleus and putamen are new structures phylogenetically, which are called the neostriatum. While, the globus pallidus is referred to as the paleos

18、triatum., The claustrum (屏状核) It is a thin sheet of grey matter coexistent with the insula and the putamen of the lentiform nucleus, from which it is separated by the fibres of the external capsule ., The amygdaloid nucleus It lies at the end of the tail of the caudate nucleus in the temporal lobe,

19、and is a component of the olfactory and limbic systems.,2. The medullary center,It is composed of three kinds of fibres depending on the nature of their connections., The association fibers(联络纤维): They are confined to a hemisphere connecting one cortical area with another, such as: arcuate fibers su

20、perior longitudinal fasciculus inferior longitudinal fasciculus cingulum(扣带) uncinte fasciculus (钩束), The commissural fibers(连合纤维) : They connect the gyri in one hemisphere to the gyri in the other hemisphere .,Most of these fibres constitute the corpus callosum(胼胝体), the remainder are included in t

21、wo very small bundles, the anterior and posterior commissures.,can be divided into 4 parts : the rostrum (嘴部) genu (膝部) Body(体部) Splenium(压部), The projection fibers: They are connections between the cortex and the subcortical structures.,Internal capsule:,The projection fibres are concentrated in th

22、e internal capsule. It consists of an anterior limb, a genu, and a posterior limb, which have topographic relations with adjacent grey masses.,anterior limb is bounded by the lenticular nucleus and the head of the caudate nucleus, genu is medial to the apex of the lenticular nucleus. posterior limb

23、is between the lenticular nucleus and the thalamus.,Ant. thalamic radiation and frontopontine tract occupy the anterior limb. Corticonuclear tract enters the genu.,Corticospinal tract, central thalamic radiation, acoustic radiation, optic radiation, parietooccipitotemporal tract were situated in the

24、 post. limb,3. The lat. Ventricle,They are roughly c-shaped cavities lined by ependymal epithelium one in each cerebral hemisphere, and filled with cerebrospinal fiuid.,Each lateral ventricle consists of a body in the region of the parietal lobe from which anterior, posterior, and inferior horns ext

25、end into the frontal. occipital, and temporal lobes.,The lateral ventricles communicate with the third ventricle through the interventricular foramen. Choroids plexus of lat. ventricle: produces C.S.F,4. The limbic system, The limbic system consists of limbic lobe (the cingulated, parahippocampal gy

26、rus, uncus and the hippocampal formation) as well as associated subcortical structures (amygdaloid body, septal nuclei, anterior nucleus of thalamus, the hypothalamus et al.).,The limbic system is concerned with: emotional expression and genesis (发生）, together with visceral response to the emotions., survival of individual and species, cognitive（认识） processes involved in memory, visceral functions.,