Cerebrum

cerebrum : gross, sulci and gyri, functional areas, white matter, venricles

1. CEREBRUM MAJ RISHI POKHREL MBBS, MD NAIHS www.slideshare.net

2. CEREBRUM Cerebral cortex Gross anatomy Sulci and gyri Functional areas White matter Ventricular system

3. Borders and surfaces 4 borders Superomedial Inferolateral with seprciliary Medial orbital Medial occipital 3 surfaces Superolateral Medial Inferior Orbital tentorial

4. 7 3 Poles

5. Lobes

6. Insula

7. 3 surfaces

8. Sulci and gyri

9. Functional areas of brain Brodmann's area – 47 -52 B ased on cytoarchitectonics Sensory and motor, Primary and association Multimodal association areas (75% ) Previously denoted by Ms or Sm now by nos

10. Primary motor area Primary sensory area Premotor area Frontal eye field Motor speech (Broca ’ s) area Language comprehension (Wernicke ’ s) area Primary visual area Leg Leg Arm Arm Face Face Pharynx Larynx Important Areas Auditory area

11. Frontal Lobe

12. Frontal Lobe

13. Parietal Lobe

14. Parietal Lobe

15. Parietal Lobe 43

16. Temporal Lobe

17. Occipital Lobe

18. Medial Surface

19. Homunculus

20. Important Areas

21. Important Areas

22. Applied anatomy

23. Collection of nerve fibres: Tracts , Fasciculi, Lemnisci, Peduncles, Commissure etc. Myelination : Oligodendrocytes in CNS & Schwann cells in PNS Collection of nerve cell bodies within white matter of CNS: nuclei WHITE MATTER OF CEREBRUM

24. CLASSIFICATION OF NERVE FIBERS Association Fibres : Connect different cortical areas of the same hemisphere Commissural Fibres : Connect wide areas of Cx of both hemispheres across midline Projection Fibres: Connect cerebral cx with subcortical grey matter of BG, Thalamus, Brain stem & Spinal cord

25. ASSOCIATION FIBRES Short and Long

26. LONG ASSOCIATION FIBRES Uncinate Fasciculus : Connects Broca ’ s area with Temp pole & Superior Temp Gyrus Expression of speech Cingulam : Connects various parts of Limbic lobe (Cingulate & Parahippocampal gyri)

27. Sup Longitudinal Fasciculus : Lateral to Corona radiata Frontal lobe with visual asso areas & Temporal lobe Fronto-occipital fasciculus : Medial to C Radiata Frontal lobe with Occipital & Temp lobes Inferior Longitudinal Fasciculus : Temp lobe with Areas 18 & 19 of occipital lobe

28. COMMISSURAL FIBRES Types: Homotopical : Connect identical areas Heterotopical : Connect n on -identical areas Examples : Corpus callosum Ant commissure, Post commissure Hippocampal & Habenular commissures A P

29. CORPUS CALLOSUM Largest band of commissural fibres which connects wide areas of Neocortex except lower and ant parts of temporal lobe Well developed in man 300 million finely myelinated fibres 10 cms long Location : Ant end : 4cm behind frontal pole Post end : 6cm in front of Occipital pole A P

30. CORPUS CALLOSUM PARTS : Splenium, Trunk, Genu, Rostrum Rostrum - continuous below with Lamina terminalis A P

31. 46 Parts of Corpus Callosum

32. Forceps Major Forceps Minor CORPUS CALLOSUM

33. Rostrum : orbital surfaces of 2 frontal lobes Forceps minor : fibers of genu – 2 frontal lobes Tapetum : fibers of trunk and splenium – do not intersect with corona radiata, forms roof and lateral wall of post horn and lateral wall of inferior horn of lateral ventricles. Forceps major : fibers of splenium – 2 occipital lobes.

34. CORPUS CALLOSUM : TAPETUM TAPETUM Forceps major LAT VENTRICLE : POSTERIOR HORN

35. LAT VENTRICLE : INFERIOR HORN TAPETUM OF CC Stria terminalis (Med) Tail of Caudate Nu INF HORN Collateral eminence

36. CORPUS CALLOSUM Function : Interhemispheric transfer of information essential for bilateral response & learning process Applied : congenital absence / surgical divn does not produce any serious neurological deficit Split brain syndrome :

37. COMMISSURAL FIBRES – Cont ’ d Ant commissure : Ant part : Allocortex Post part : Neocortex Post commissure : Connect Sup colliculi, Pretectal nuclei, Nu of post commissure, Interstitial nu etc. Role in consensual pupillary light reflex Hippocampal commissure : Connects crura of Fornix Habenular commissure : Connect habenular Nu (Limbic system)

38. WHITE MATTER : CEREBRUM PROJECTION FIBRES Connect cerebral cx with subcortical grey matter like BG, Thalamus, Brain stem & Spinal cord. Cortico-fugal & cortico-petal fibres E.g. Corona radiata & Int capsule of Neo cortex Fimbriae & Fornix of Allocortex

39. CORONA RADIATA Fan shaped arrangement of projection fibers from neo-cortex converging to the periphery of Corpus striatum Continues below as Internal capsule CORONA RADIATA

40. INTERNAL CAPSULE A compact band of neocortical projection fibres Main highway for input & output fibres of cerebral cx Continues above as corona radiata & below as crus cerebri of midbrain V- shaped in horizontal section with concavity laterally

41. RELATIONS : Medial : Head of Caudate Nu & Thalamus Lateral : Lentiform Nucleus Medial Extreme capsule Lateral

42. INTERNAL CAPSULE HORIZANTAL SECTION Ant Limb Genu Post limb Retrolentiform part Sublentiform part

43. ARRANGEMENT OF FIBRES : : Cortico-reticula r Ant Thalamic radiation Ant Thal Nu –Cingulate Gyrus (Papez Circuit) Fibres of MF Bundle

44. ARRANGEMENT OF FIBRES : ANTERIOR LIMB Ant Thalamic radiation AT Nu - Gy Singuli (Papez C) Fibres of MF Bundle Fronto-Pontine Cortico-striate

45. INTERNAL CAPSULE ARRANGEMENT OF FIBRES : GENU : Cortico-reticula r Superior Thalamic radiation Cortico nuclear

46. ARRANGEMENT OF FIBRES : GENU Cortico - nuclear fibres : f rom a reas 4, 6 & 8 to motor n uclei of cranial n erves (contralateral) Superior Thalamic radiation : Thalamus to pre & post central gyri of cerebral cortex Corticoreticular

47. ARRANGEMENT OF FIBRES : POST LIMB Longer than Ant limb Cortico-rubral Superior Thalamic radiation Cortico spinal (Somatotopical) UL Tr LL Cortico-striate Fronto & Parieto-pontine

48. ARRANGEMENT OF FIBRES: POSTERIOR LIMB From Globus pallidus To Subthalamic nucleus ( Fasciculus subthalamicus ) To Thalamus (Fasciculus Lenticularis ) Nigro - striate (Comb bundle ) From Substantia Nigra to Caudate Nu & Putamen Thalamo-striate : From intralaminar & centromedian Nu to Caudate Nu & Putamen

49. SUB LENTIFORM PART : Cortico-rubral Superior Thalamic radiation Cortico spinal (Somatotopical) UL Tr LL Cortico-striate Cortico-pontine Auditory Radiation Meyer ’ s loop of optic radn Temp- pontine & Parieto - pontine

50. ARRANGEMENT OF FIBRES: SUBLENTIFORM PART Auditory Radiation MGB to Anterior Transverse Temp gyrus & Sup temporal gyrus Perception of hearing Meyer ’ s loop of optic radiation from lower part of peripheral retina to visual Cortex Temporo - pontine & Parieto – pontine fibres

51. RETROLENTIFORM PART : In lat wall of Post horn of LV Cortico-rubral Superior Thalamic radiation Cortico spinal (Somatotopical) UL Tr LL Cortico-striate Cortico-pontine Retrolentiform part Optic Radiation Area 18,19 to SC & Nu of EO Ms - Parieto & Occipito-pontine Post Thalamic Radn Sublentiform part

52. ARRANGEMENT OF FIBRES: RETROLENTIFORM PART Optic Radiation : LGB to Area 17 Area 18,19 to Sup Colliculus & Motor Nu of EO Muscles for conjugated movements of eye balls Parieto & Occipeto - pontine fibres Post Thalamic Radiation : Pulvinar (thalamus) to Areas 18,19, 39, 40 )

53. ARTERIAL SUPPLY OF I C Striate br of MCA Recurrent branch of ACA Striate br of AC A Ant Limb Genu Sublentiform part Post Limb Retrolentiform part Ant cerebral Artery Int Carotid Artery Middle cerbral A Post Cerebral Atery Ant choroidal A By central branches of cerebral arteries - End arteries

54. 70

55. INT CAPSULE : BLOOD SUPPLY ARTERY PART OF IC Striate Br of ACA Rec Br of ACA Striate Br of MCA (Charcot ’ s artery) Direct Br from ICA Ant Choroidal A P CA Ant Limb Genu Post Limb S L Part RL Part By central branches of cerebral arteries - End arteries

56. APPLIED ANATOMY Cerebrovascular accident (CVA) affecting i nt capsule cause extensive clinical effects Blood supply by end arteries Dense collection of fibres in IC Caused commonly by hemorrhage from Charcot ’ s artery Hemiplegia : UMN type paralysis of one half of the body Commonly caused by CVAs affecting IC

57. Ventricular system Communicate with each other & with SA Space (thru roof of 4th Ventricle) Allow free flow of CSF produced by Choroid plexus

58. PART SUB DIVN CAVITY FORE BRAIN Telencephalon Lateral ventricle(s) Diencephalon 3rd Ventricle MID BRAIN Cerebral Aqueduct HIND BRAIN 4th Ventricle SP CORD Central canal

59. LATERAL VENTRICLE Cavity of Telencephalon One in each cerebral hemisphere Roughly ‘C’- shaped Capacity : 7- 10ml PARTS : Body (Central part) Anterior ( Frontal lobe ) Posterior ( Occipital lobe ) Inferior ( Temporal lobe)

60. Task Draw a labeled diagram of Coronal section through Ant horn of lat ventricle Body of lat ventricle Inf horn of lateral ventricle Post horn of lat ventricle Floor of 4 th ventricle

61. ?