Internal Capsule Study Notes

INTERNAL CAPSULESituationIt is a lamina of which matter that lies betweenlentiform nucleus laterally.the caudate nudeus and thakmus medailly and theDifferent Parts- Horizontal Section(A) GenuB Anterior Limb(e) Posterior Limb.Description of each PartsDIPANKARRAYHuman Anatomy For ExamA Genu It is the convex medially directed hand of the internalCapsule opposite the anterior end of thalamus.B Anterior limb:-It is the part of internal capsule in front of genu.(B) Posterior limb:- Part of internal capsule behind the genu.Sub divisions of posterior limb(1.) Lentiform / thalamo-lentiform part:- Situated between thalamusand lentiform nucleus.(2) Retro-lentiform part: It is the part of posterior limb whichLentiform nucleus.extends for a short distance behind the(3)Sub-lentiform part:- the It is lentiform the part of posterior limb lving belownucleus.Fibres Passing through the Different Parts(A) Genuth Cortico-nudear Fibres From area 4 to motor nuclei ofFor the musdes of eye-ball and posteriorly placed fibres for thecranial nerves. Anteriorly placed fibrestongue and fare.(B)Anteriorlimb (1) Fronto-pontine-fibres:-From the frontal cortexto nudei pontis. Fibres are situated more mediallyin anterior limb.2Anterior thalamic radiation:- From the medial and anterior nucleiof thalamus to the contex of frontal lobe. Fibres are more laterally situated. INTERNAL CAPSULECONT.Fibres passing through different partsCont3Fibres from orbital Cortex to hypothalamus.Human Anatomy For Rxam(4) Anterior limb is crossed by thin lamina of gray and whitematter between caudate nucleus and putamen.(c) POSTEROR UMB(1.)THROUGH LENTIFORM OR THALAMO - -LENTIFORM PARTi)Cortico-spinal Tract :- Fibres for the week are nearest to the genu.trunk and lower exbemity from before backwards.This is followed by the fibres of upper extremity(iii) Superior thalamic Radiation:- Superior thalamic radiation projectspost. Central gyrus. Their fibres arelying behind the cortio-spinal tract.general sensation of the body to the(iii) Fronto-pontine Fibres :- From area 6 and 8 to pontine nuclei(iv) Cortino -nibral Tract:- From frontal lobe to red nucleus.VFasciculars lenticularis(vi) Sub-thalamic fascirulus2THROUGH RETRO-LENTIFOR PART(i) Optic Radiation :- From lateral geniculare body to arta 17.(ii) Paracto-pontine or Occipital pontine fibres:- From the parietal andoccipital lobe to portine nudeus.(iii) Fibres nudeus. from occipital nudeus to superior Colliculus and pre-tectal3SUB-LENTIFORM PART(i) Auditory Radiation(ii) Temporo-portine paricto-pontine andOrspito-pontine fibres. INTERNAL CAPSULECont..BLOOD SUPPLYThe antery supplying the internal capsule can bearranged as follows;HUMAN ANATOMY(A) ANTERIOR UMBDIRANKAH RAYFOR EXAMB GENU(i) Striate branches of middle and anterior is Straight branches from middleCerebral artery.(ii) Recument branch of anterior cerebral A.(ii)Cerebral Artery.(iii) Recument branch of anteriorPosterior communicating Artery.(c) POSTERIOR LIMBcerebral artery.a Lentiform Part State brandres from middle cerebral artery.(ii) Anterior choroid artery.(iii) Postero-loteral branches of posterior cerebral artery.(b) Retro-lentiform Part:- Posterior lateral branches of posteriorCerebral artery.(c) Sub-lentform Part:-(i) Anterior choroid artery.(ii) Postero lateral brandres of posterior cerebral artery.