Central Nervous System Anatomy Lesson 5

Functional Anatomy: CNS Major Divisions Forebrain, Midbrain, Hindbrain Know structure name, location & general function Major fiber systems CNS vs PNS terminology nucleus vs. ganglion tracts vs. nerves ~

Telencephalon - Cortex Gray Matter Somas and Dendrites (neuron cell bodies) Organized in layers some input, some output Neocortex 6 layers ~

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

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

Anterior Anterior

Forebrain Fibers Systems Association Fibers interconnect cortical areas within each hemisphere Projection Fibers all other *CNS fiber systems Fornix Corticospinal tract Mammillothalamic tract Naming convention ~

Hemispheres Left Right Association Commissural Projection

Subcortical: Limbic System Emotion; Learning & Memory Structures Cingulate gyrus Hippocampus Amygdala Thalamus Hypothalamus Mammilary bodies Olfactory bulbs Fornix ~

Limbic System Cingulate gyrus Hippocampus Fornix Thalamus Hypothalamus Amygdala

Subcortical: Basal Ganglia Extrapyramidal Motor System Caudate Putamen Globus Pallidus Striatum Lenticular Nucleus Claustrum ~

Caudate Globus pallidus Putamen

Forebrain Subcortical Areas Diencephalon Surrounds 3rd ventricle Thalamus sensory and motor relay nuclei Hypothalamus motivation & emotion ~

Thalamus Lateral Geniculate Nuclei LGN vision Medial Geniculate Nuclei MGN audition Ventroposterior Nuclei - VPL & VPM Somatosensation ~

Hypothalamus 4Fs Feeding Fighting fleeing, and ... mating Controls the pituitary gland ~

Thalamus Hypothalamus Pituitary Stalk

Mesencephalon Surrounds cerebral aqueduct Tectum Superior Colliculi - vision Inferior Colliculi - audition Tegmentum ~

Thalamus Superior Colliculi Inferior Colliculi Tectum

Tegmentum Periaqueductal Gray analgesia Reticular Formation – sleep and arousal attention Red Nucleus and Substantia Nigra motor system Ventral Tegmental Area (VTA) reinforcement ~

Cross-section of Tegmentum Reticular formation Dorsal PAG Red Nucleus Substantia Nigra Ventral Tegmental Area

Metencephalon Surrounds fourth ventricle Cerebellum coordinates movements Pons Sleep and arousal Reticular formation ~

Myelencephalon Medulla “Vital Centers” Reticular formation Pyramids ~

Thalamus Medulla