Anatomy of theCentral Nervous

System

Lecture 3

Telencephalon - Cortex

Gray Matter Somas and Dendrites

Neocortex - 6 layers Sensory input ---> layer IV Motor output ---> layer V

Paleocortex - 2 or 3 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

Association Fibers

interconnect cortical areas within each hemisphere

Projection Fibers

all other fiber systems Fornix Corticospinal tract Mammillothalamic tract

Naming convention ~

Association

Commissural

Projection

HemispheresLeft Right

The Limbic System

Emotion Learning & Memory Structures

Thalamus Hypothalamus Hippocampus Cingulate gyrus Amygdala Fornix ~

Amygdala

Hippocampus

Limbic System

Thalamus

Hypothalamus

Cingulate gyrus

Fornix

Basal Ganglia

Extrapyramidal Motor System Caudate Putamen Globus Pallidus

Claustrum Amygdala

no motor function ~

Striatum

Lenticular Nucleus

Caudate

AmygdalaPutamen

Globuspallidus

Claustrum

Diencephalon

Surrounds third 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 Massa Intermedia - crosses midline ~

Hypothalamus

4Fs

feeding

fighting

fleeing, and ...

mating Controls the pituitary gland ~

Diencephalon: thalamus

LGNMGN

MassaIntermedia

Diencephalon

HypothalamusPituitary Stalk

Mesencephalon

Surrounds cerebral aqueduct Tectum

Superior Colliculi - vision Inferior Colliculi - audition

Tegmentum

Thalamus

Tectum

SuperiorColliculi

InferiorColliculi

Tegmentum

Periaqueductal Gray - pain 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

VentralTegmentalArea

Dorsal

Red Nucleus

Metencephalon

Surrounds fourth ventricle Cerebellum

coordinates movements Pons

Sleep and arousal Reticular formation ~

Cerebellum

Pons

Medulla - “Vital Centers”

Reticular formation

Myelencephalon

Thalamus

Medulla

Dorsal

Ventral

WhiteMatter

GrayMatter

CentralCanal

Spinal Cord

Dorsal

Ventral

Dorsal

Lateral

Ventral

Horns

Spinal Cord

Spinal cord

Dorsal horn - sensory input Lateral horn - autonomic N.S. Ventral horn - motor output ~