Anatomy of the Central Nervous System: Forebrain Lecture 5

Telencephalon - Cortex n Gray Matter l Somas and Dendrites n Neocortex - 6 layers l Sensory input ---> layer IV l Motor output ---> layer V n Paleocortex - 2 or 3 layers ~

Telencephalon - Fiber Systems n White Matter - myelinated axons n 3 types of fiber systems l Commissural l Association l Projection ~

Commissural Fibers n Interconnect homologous structures in the two hemispheres l Corpus Callosum l Anterior and Posterior l Hippocampal ~

Anterior

n Association Fibers l interconnect cortical areas within each hemisphere n Projection Fibers all other fiber systems l Fornix l Corticospinal tract l Mammillothalamic tract n Naming convention ~ Association & Projection Fibers

Association Commissural Projection Hemispheres Left Right

The Limbic System n Emotion n Learning & Memory n Structures l Thalamus l Hypothalamus l Hippocampus l Cingulate gyrus l Amygdala l Fornix ~

Amygdala Hippocampus Limbic System Thalamus Hypothalamus Cingulate gyrus Fornix

Basal Ganglia n Extrapyramidal Motor System l Caudate l Putamen l Globus Pallidus Striatum Lenticular Nucleus l Claustrum l Amygdala no motor function ~

Caudate Amygdala Putamen Globus pallidus

Claustrum

Diencephalon n Surrounds third ventricle n Thalamus l sensory and motor relay nuclei n Hypothalamus l motivation & emotion ~

Thalamus n Lateral Geniculate Nuclei - LGN l vision n Medial Geniculate Nuclei - MGN l audition n Ventroposterior Nuclei - VPL & VPM l somatosensation n Massa Intermedia - crosses midline ~

Hypothalamus n Control of behaviors critical to survival l Feeding l Fighting l Fleeing l Mating n Controls the pituitary gland ~

Thalamus

Diencephalon: thalamus LGN MGN Massa Intermedia

Diencephalon Hypothalamus Pituitary Stalk