Anatomy of the Central Nervous System Lesson 3
Functional Anatomy: CNS Major Divisions Forebrain, Midbrain, Hindbrain Know structure location & general function Major fiber systems CNS vs PNS terminology nucleus vs. ganglion tracts vs. nerves ~
Forebrain - Cortex Gray Matter Somas and Dendrites Organized in layers some input, some output Neocortex 6 layers ~
Forebrain - 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 fiber systems Fornix Corticospinal tract Mammillothalamic tract Naming convention ~
Hemispheres Left Right Association Commissural Projection
Forebrain Subcortical Areas Diencephalon Surrounds 3rd ventricle Thalamus sensory and motor relay nuclei Hypothalamus motivation & emotion ~
Thalamus vision Lateral Geniculate Nuclei LGN Medial Geniculate Nuclei MGN audition ~
Hypothalamus 4Fs Feeding Fighting fleeing, and ... mating Controls the pituitary gland ~
Thalamus
Thalamus & Hypothalamus MGN LGN Hypothalamus Pituitary Stalk
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 3 motor nuclei Caudate Putamen Globus Pallidus ~ Striatum
Caudate Globus pallidus Putamen
Midbrain Surrounds cerebral aqueduct Tectum Superior Colliculi - vision Inferior Colliculi - audition Tegmentum substantia nigra - motor many other nuclei sleep/wake cycle pain & analgesia positive reinforcement ~
Thalamus Superior Colliculi Inferior Colliculi Tectum Tegmentum Medulla
Cross-section of Tegmentum Dorsal Substantia Nigra
Hindbrain Cerebellum coordinates movements Pons Sleep and arousal Medulla vital functions many cranial nerves ~
Cerebellum Pons
Spinal Cord Dorsal Gray Matter Horns Dorsal White Matter Ventral Central Canal