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The limbic systemThe limbic system
Neuronal circuitry Neuronal circuitry controls of emotional controls of emotional behavior and motivational behavior and motivational drivesdrives
Composed of subcortical and Composed of subcortical and cortical componentscortical components
Limbic SystemLimbic System
Figure 12.18
limbiclimbic
Subcortical Subcortical groupgroup
Hypothalamus ,septum,paraolfactHypothalamus ,septum,paraolfactory area,epithalamus,ant.thalamic ory area,epithalamus,ant.thalamic nuclei,hippocampus,amygdala,basnuclei,hippocampus,amygdala,bas
al gangelial gangeli
Limbic cortexLimbic cortex
Orbitofrontal Orbitofrontal coretx,subcallosal gyrous coretx,subcallosal gyrous
cingulate gyrus and cingulate gyrus and parahippocamp gyrousparahippocamp gyrous
Limbic System: Emotion Limbic System: Emotion and Cognitionand Cognition
The limbic system interacts with the The limbic system interacts with the prefrontal lobes, therefore:prefrontal lobes, therefore: One can react emotionally to conscious One can react emotionally to conscious
understandingsunderstandings One is consciously aware of emotion in One is consciously aware of emotion in
one’s lifeone’s life Hippocampal structures – convert Hippocampal structures – convert
new information into long-term new information into long-term memoriesmemories
The hypothalamus not The hypothalamus not only influences how you only influences how you feel, it influences how feel, it influences how
you interpret the you interpret the consequences of those consequences of those
feelings.feelings.
limbiclimbic
VisceralAfferents
Nucleusof the
Solitary Tract
Brain StemNuclei
AutonomicPreganglionic
Nuclei
HormonalOutput
AutonomicOutput
TargetOrgans
HypothalamicNuclei
Hypothalamic Role in Emotion
Hypothalamus
PituitaryReleasing Factors
AutonomicNervous System
Adenohypophysis(Anterior Pituitary)
Neurohypophysis(Posterior Pituitary)
Sympathetic
Parasympathetic
“I feel fear!”
Hypothalamus
AmygdalaAmygdala
Cortex, Cortex, septumseptum
medial forebrain
bundle
Amygdala Amygdala ventral
routeBrainstemBrainstemspinal cordspinal cord
medial
forebrain
bundle
stria
terminalis
Anterior NucleusAnterior Nucleusmtt
BrainstemBrainstemdorsal long.
fasciculus
post.post.magno
(SO, PV)ant.ant.parvo
PituitaryPituitary
Hypothalamus,MajorHypothalamus,Major
Hypothalamus is the most important Hypothalamus is the most important output sorce output sorce
It communicate with brain stem by It communicate with brain stem by medial forebrain medial forebrain bundle ,bidirectionaly between bundle ,bidirectionaly between forebrain and brain stem forebrain and brain stem
Hypothalamus cont.Hypothalamus cont.
Controls: Controls: 1-vegetative and 1-vegetative and endocrine functions 2-endocrine functions 2-behavior and motivationbehavior and motivation
vegetative and endocrine vegetative and endocrine functionsfunctions
Cardiovascular regulation involves Cardiovascular regulation involves 1-Post. And lateral 1-Post. And lateral hypothalamus area, increase BP and hypothalamus area, increase BP and HR. HR. 2-preoptic area ,decrease BP and HR 2-preoptic area ,decrease BP and HR *1and 2 mediated by *1and 2 mediated by cardiovascular centre in the pontile cardiovascular centre in the pontile and medullary part of reticular and medullary part of reticular formation formation
Body temperature Body temperature regulationregulation
Preoptic area Preoptic area
Thermo-regulation Thermo-regulation (body temperature)(body temperature)
Involves autonomic nervous, endocrine, Involves autonomic nervous, endocrine, and skeletomotor systemsand skeletomotor systems
Body temperature detectorsBody temperature detectors Peripheral: skin, spinal cord, visceraPeripheral: skin, spinal cord, viscera Central: anterior hypothalamusCentral: anterior hypothalamus
Body temperature effectorsBody temperature effectors Heat retention or generation: Heat retention or generation:
posterior hypothalamusposterior hypothalamus Heat dissipation: anterior Heat dissipation: anterior
hypothalamushypothalamus
Thermo-regulation Thermo-regulation (body temperature)(body temperature)
Heat dissipating mechanismsHeat dissipating mechanisms Dilation of blood vessels in the skin Dilation of blood vessels in the skin Inhibition of shiveringInhibition of shivering
Heat conserving mechanismsHeat conserving mechanisms Vasoconstriction of blood vessels in Vasoconstriction of blood vessels in
the skinthe skin Shivering Shivering Increased secretion of thyroxinIncreased secretion of thyroxin
Methods of thermo-regulation by the body
Response to Cold Response to Heat
Regulation of body water Regulation of body water intakeintake
Thirst centre,lateral hypothalamusThirst centre,lateral hypothalamus Electrolyte concentrationmaking Electrolyte concentrationmaking
desire to drinkdesire to drink Supraopticx:urinary excrition due to Supraopticx:urinary excrition due to
ADH ADH
ThirstThirst
Function of serum osmolality and blood Function of serum osmolality and blood volumevolume
Osmotic receptors in the hypothalamusOsmotic receptors in the hypothalamus Volume receptors in the right atrium of Volume receptors in the right atrium of
the heart and great veinsthe heart and great veins Vasopressin release from hypothalamusVasopressin release from hypothalamus
Increases water reabsorption from Increases water reabsorption from the kidneythe kidney
Inhibited by ethanolInhibited by ethanol
Circadian RhythmCircadian Rhythm Oscillations during the course of the dayOscillations during the course of the day
CorticosteriodsCorticosteriods
Feeding and drinking behaviorFeeding and drinking behavior
Growth hormone secretionGrowth hormone secretion
Lesions of the suprachiasmatic nuclei of Lesions of the suprachiasmatic nuclei of
the hypothalamus disrupts these the hypothalamus disrupts these oscillationsoscillations
Control of Feeding
FeedingFeeding Complex interaction of many systemsComplex interaction of many systems Regulation of energy metabolism by the Regulation of energy metabolism by the
Ventromedial and Lateral nuclei of the Ventromedial and Lateral nuclei of the hypothalamushypothalamus Physical Lesions produce hyperphagia and Physical Lesions produce hyperphagia and
obesity or reduced attention to food.obesity or reduced attention to food. Amygdala may also be involved indirectlyAmygdala may also be involved indirectly
Lesions produce hyperphagia-like symptomsLesions produce hyperphagia-like symptoms Ventromedial hypothalamic lesions also cause Ventromedial hypothalamic lesions also cause
increased insulin secretion Obesity.increased insulin secretion Obesity.
Feedback Mechanisms Feedback Mechanisms Controlling FeedingControlling Feeding
Feedback from gut hormonesFeedback from gut hormones e.g. Cholecystokinine.g. Cholecystokinin
Released from small intestine in Released from small intestine in response to feedingresponse to feeding
Inhibits or suppresses feedingInhibits or suppresses feeding
Uterine contraction and Uterine contraction and milk ejectionmilk ejection
Oxytocin stimulation by Oxytocin stimulation by PARAVENTRICULAR PARAVENTRICULAR
هسته آميگدال و ارتباط آن با نواحي مختلف مغز
ارتباطات عصبي سيستم ليمبيك
ارتباطات اصلي شكنج سينگوال
مسيرهاي پردازش اطالعات
Hippocampus circuitHippocampus circuit
Ent. cortex From perforant To Ent. cortex From perforant To dentate gyrous mossy fiber cA3 dentate gyrous mossy fiber cA3 schaffer collaterals cA1 to subiculum schaffer collaterals cA1 to subiculum to ento cortex to ento cortex