Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Limbic system

519 views

Published on

  • Be the first to comment

Limbic system

  1. 1. LIMBICLIMBIC SYSTEMSYSTEM && RETICULARRETICULAR FORMATIONFORMATION
  2. 2. LEARNING OBJECTIVESLEARNING OBJECTIVES
  3. 3. I.I. Anatomical Location + discussion ofAnatomical Location + discussion of components.components. II.II. Structure and function of theStructure and function of the hippocampal formation.hippocampal formation. III.III. The Amygdaloid nucleus complex andThe Amygdaloid nucleus complex and the function of its 3 components.the function of its 3 components. IV.IV. Links between the limbic system andLinks between the limbic system and effector (behaviour) systems.effector (behaviour) systems. V.V. Links between neurotransmitter-Links between neurotransmitter- specific projection systems and thespecific projection systems and the limbic system.limbic system. VI.VI. Regional Anatomy of these structures.Regional Anatomy of these structures.
  4. 4. LIMBIC SYSTEMLIMBIC SYSTEM
  5. 5. I.I. Anatomical Location and Overview.Anatomical Location and Overview. A.A. Limbic association cortex –Limbic association cortex – surrounding diencephalonsurrounding diencephalon -medial + inferior (orbital) surface-medial + inferior (orbital) surface  cingulate gyrus, parahippocampalcingulate gyrus, parahippocampal gyrus, orbital gyrus, temporal pole.gyrus, orbital gyrus, temporal pole.
  6. 6. FUNCTIONSFUNCTIONS EmotionsEmotions (Expression of Feelings)(Expression of Feelings) FEAR(Fight or Flight))FEAR(Fight or Flight)) BehaviorBehavior MemoryMemory
  7. 7.  Anatomically refers to areasAnatomically refers to areas surroundingsurrounding the diencephalon (limbus =the diencephalon (limbus = border) and bordering the cerebralborder) and bordering the cerebral cortex.cortex.  In 1878 Broca introduced the nameIn 1878 Broca introduced the name LIMBIC SYSTEMLIMBIC SYSTEM
  8. 8.  The “C”-shaped hippocampal formationThe “C”-shaped hippocampal formation and includes the amygdala, cingulateand includes the amygdala, cingulate and parahippocampal cortices.and parahippocampal cortices. The key to learning, memory, andThe key to learning, memory, and behavior (including emotional behavior)behavior (including emotional behavior) – of paramount importance in– of paramount importance in psychiatry.psychiatry.
  9. 9. ANATOMICAL COMPONENTSANATOMICAL COMPONENTS  Olfactory pathwayOlfactory pathway  Pyriform lobePyriform lobe  Amygdaloid bodyAmygdaloid body  Hippocampal formationHippocampal formation  Limbic lobeLimbic lobe
  10. 10.  Hypothalamus, AN thalamus, habenularHypothalamus, AN thalamus, habenular N, interpeduncular N, midbrain tegmentalN, interpeduncular N, midbrain tegmental N, strai medullaris thalami, fasciculusN, strai medullaris thalami, fasciculus retroflexus & median forebrain bundleretroflexus & median forebrain bundle
  11. 11. LIMBIC LOBELIMBIC LOBE
  12. 12. Limbic System: Cortical Areas Figs. 16-2 and 3 Note: surrounding diencephalon, medial + inferior (orbital) surface  [cinglulate gyrus, parahipp gyrus, orbital gyrus, temporal pole]. These cortices are near other association cortices and project to:
  13. 13. B. the Hippocampal Formation and Amygdala. The “C” shape, along with the major output paths for the hippocampus: the fornix.
  14. 14. CORTICAL & SUBCORTICALCORTICAL & SUBCORTICAL STRUCTURES FORMINGSTRUCTURES FORMING LIMBIC SYSTEMLIMBIC SYSTEM
  15. 15. Look!!
  16. 16. Limbic SystemLimbic System  The limbic system isThe limbic system is comprised ofcomprised of – Hippocampus: involved inHippocampus: involved in learning and memorylearning and memory – Amygdala: involved inAmygdala: involved in emotionemotion – Mammillary BodiesMammillary Bodies  TheThe fornixfornix is a fiber bundleis a fiber bundle that interconnects thethat interconnects the hippocampus with thehippocampus with the mammillary bodiesmammillary bodies
  17. 17. The Limbic SystemThe Limbic System
  18. 18. PAPEZ CIRCUITPAPEZ CIRCUIT
  19. 19. PAPEZ CIRCUITPAPEZ CIRCUIT  Papez circuit consists of hippocampus,Papez circuit consists of hippocampus, fornix, mammillothalamic tract, anteriorfornix, mammillothalamic tract, anterior thalamic nuclei, thalamocingular radiation,thalamic nuclei, thalamocingular radiation, cingulate gyrus and cingulohippocampalcingulate gyrus and cingulohippocampal fibersfibers
  20. 20. SUBCORTICAL REGIONSUBCORTICAL REGION (Limbic)(Limbic)
  21. 21. AMYGDALAAMYGDALA
  22. 22.  Superiorly it is related to the anterior partSuperiorly it is related to the anterior part of lentiform nucleus.of lentiform nucleus.  Inferiorly it is related to uncus.Inferiorly it is related to uncus.  Medially it extends to the inferior surfaceMedially it extends to the inferior surface of the cortex of the temporal lobe.of the cortex of the temporal lobe.
  23. 23.  The dorsomedial part of amygdaloid bodyThe dorsomedial part of amygdaloid body is connected with the primary olfactoryis connected with the primary olfactory area while venteromedial part isarea while venteromedial part is component of limbic system.component of limbic system.  Feeling of fear & apprehension leading toFeeling of fear & apprehension leading to aggressionaggression
  24. 24. CONNECTIONS OFCONNECTIONS OF AMYGDALAAMYGDALA
  25. 25. SEPTAL AREASEPTAL AREA
  26. 26.  The cortex of the septal region is presentThe cortex of the septal region is present infront of lamina terminalis beneath theinfront of lamina terminalis beneath the genu & rostrum of corpus callosum.genu & rostrum of corpus callosum.  The paraolfactory area or the subcallosalThe paraolfactory area or the subcallosal gyrus lies underneath the rostrum ofgyrus lies underneath the rostrum of corpus callosum.corpus callosum.  Posterior to parolfactory area & justPosterior to parolfactory area & just anterior to lamina terminalis isanterior to lamina terminalis is paraterminal gyrusparaterminal gyrus
  27. 27. CLINICAL ANATOMYCLINICAL ANATOMY  Alzheimers DiseaseAlzheimers Disease  Papez circuitPapez circuit  Brucy Calvier SyndromeBrucy Calvier Syndrome  EpilepsyEpilepsy  DementiaDementia
  28. 28. Feelings & EmotionsFeelings & Emotions (Emotion is expression of feelings(Emotion is expression of feelings andand Antiemotions is Depression)Antiemotions is Depression)  Nature controls Man by two things Pain and PleasureNature controls Man by two things Pain and Pleasure (Patient =Suffering)(Patient =Suffering) Pain is PunishmentPain is Punishment Pleasure is RewardPleasure is Reward FEAR (DANGER):Horror,HauntedFEAR (DANGER):Horror,Haunted FightFight FrightFright HypothalamusHypothalamus SympatheticSympathetic EndocrineEndocrine Amygdaloid damage- ends Fear (Fearless)Amygdaloid damage- ends Fear (Fearless)
  29. 29. Food & SexFood & Sex  Nature`s Priorities (Biological needs)areNature`s Priorities (Biological needs)are  Preservation of life(Food)Preservation of life(Food)  Procreation of life(Sex)Procreation of life(Sex)  Human hasHuman has  self conciousness(I)self conciousness(I)  emotionsemotions  memorymemory  Damage to Amygdaloid leads to abnormal foodDamage to Amygdaloid leads to abnormal food habits & Sex (Hypersexualty)habits & Sex (Hypersexualty)
  30. 30. MemoryMemory(Storage of information(Storage of information))  Alzheimers DiseaseAlzheimers Disease  HIPPOCAMPAL DAMAGE CAUSESHIPPOCAMPAL DAMAGE CAUSES LOSS OF RECENT MEMORYLOSS OF RECENT MEMORY
  31. 31. RETICULAR FORMATIONRETICULAR FORMATION
  32. 32.  Diffuse network of nerve fibers & neuronsDiffuse network of nerve fibers & neurons  In tegmental core throughout brainstem.In tegmental core throughout brainstem.  Fills space not occupied by cranial nerveFills space not occupied by cranial nerve nuclei/ other nuclei/ tracts.nuclei/ other nuclei/ tracts.
  33. 33. FUNCTIONFUNCTION  Concerned with arousal or alertness byConcerned with arousal or alertness by ARASARAS  Maintains muscle tone & posture duringMaintains muscle tone & posture during sitting and standing by reticulospinal tractsitting and standing by reticulospinal tract  Seratonergic fibers induce slow sleep &Seratonergic fibers induce slow sleep & dimnish pain sensationdimnish pain sensation  Nadr. fibers produce paradoxical sleepNadr. fibers produce paradoxical sleep  Dopaminergic fibers preventsDopaminergic fibers prevents parkinsonian tremor & rigidityparkinsonian tremor & rigidity
  34. 34.  TS through brainstem & spinal cordTS through brainstem & spinal cord showing the reticular formationshowing the reticular formation
  35. 35. EXTENT OF RETICULAREXTENT OF RETICULAR FORMATIONFORMATION SUPERIORLY:SUPERIORLY:  Reticular nucleus &Reticular nucleus & subthalamic nuclleussubthalamic nuclleus  INFERIORLY :INFERIORLY :  Cervical spinal cordCervical spinal cord
  36. 36. RETICULAR NUCLEI INRETICULAR NUCLEI IN BRAINSTEMBRAINSTEM
  37. 37. EFFERENT & AFFERENTEFFERENT & AFFERENT CONNECTIONSCONNECTIONS
  38. 38. Various nuclear regions inVarious nuclear regions in reticular formation between wellreticular formation between well defined cranial nerve nucleidefined cranial nerve nuclei
  39. 39. ASCENDING RETICULARASCENDING RETICULAR ACTIVATING SYSTEMACTIVATING SYSTEM  Ascending fibers of reticular formation toAscending fibers of reticular formation to cerebral cortex and limbic systemcerebral cortex and limbic system  Convey diffuse input from all sensoryConvey diffuse input from all sensory systemssystems  Concerned with degree of conciousnessConcerned with degree of conciousness from sleep to arousalfrom sleep to arousal

×