Anatomy of theCentral Nervous

SystemLesson 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 ~

Forebrain - Cortex

Gray Matter Somas and Dendrites (neuron cell

bodies) 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 ~

AnteriorAnterior

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 ~

Association

CommissuralProjection

HemispheresLeft Right

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 ~

Hypothalamus

4Fs Feeding Fighting fleeing, and ... mating

Controls the pituitary gland ~

Subcortical: Limbic System Emotion; Learning & Memory Structures

Cingulate gyrus Hippocampus Amygdala Thalamus Hypothalamus Mammilary bodies Olfactory bulbs Fornix ~

Limbic System

Subcortical: Basal Ganglia

3 motor nuclei Caudate Putamen Globus Pallidus ~

Striatum

Midbrain Surrounds cerebral aqueduct Tectum

Superior Colliculi - vision Inferior Colliculi - audition

Tegmentum substantia nigra - motor Reticular formation

sleep/wake cycle many other nuclei ~

Cross-section of Tegmentum

Dorsal

Hindbrain

Cerebellum coordinates movements

Pons Sleep and arousal

Medulla vital functions many cranial nerves ~