Central Nervous System Anatomy

Lesson 6

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 ~

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

Subcortical: Limbic System Emotion; Learning & Memory Structures

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

Amygdala

Hippocampus

Limbic System

Thalamus

Hypothalamus

Cingulate gyrus

Fornix

Subcortical: Basal Ganglia

Extrapyramidal Motor System Caudate Putamen Globus Pallidus

Striatum

Lenticular Nucleus

Claustrum ~

Caudate

Putamen

Globuspallidus

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

Tectum

SuperiorColliculi

InferiorColliculi

Tegmentum

Tegmentum Periaqueductal Gray

analgesia Reticular Formation –

sleep and arousal attention

Red Nucleus and Substantia Nigra motor system

Ventral Tegmental Area (VTA) reinforcement ~

PAG

Substantia Nigra

Reticular formation

Cross-section of Tegmentum

Dorsal

Red Nucleus

VentralTegmentalArea

Metencephalon

Surrounds fourth ventricle Pons

Sleep and arousal Reticular formation

Cerebellum coordinates movements ~

Myelencephalon

Medulla “Vital Centers” Reticular formation Pyramids ~

Thalamus

Medulla