SPINAL CORD

Spinal Nerves Dermatomes

GrossGross Spinal Cord

Gross Structure

FGFC Dorsal Columns

Dorsal horn

FGFC

Dorsal hornLateral Columns

Intermediate hornhorn

Ventral horn Ventral Columns

Where are the sensory and motor nuclei?nuclei?

Alar plate – sensory

•Basal plate – motor

Gross Structure

Dorsal hornDorsal horn

Intermediate hornhorn

Ventral horn

Gray Matter & Nuclear Structure

Dorsal/Sensory Organization

Ventral/Motor Organization

Input

Motor neuronInterneuron

Output

Spinal Cord Levels

Ventral Horn / Motor Organization

Ventral Horn / Motor OrganizationOrganization

Stretch Reflex

Ia fromspindle

ExtrafusalFiber,E t

T E t

Extensor Muscle

To Flexor

To Extensormuscle

Intrafusal muscle To Flexor,

antagonist musclemuscle

Cutaneous Reflex

Cutaneous Reflex

PAIN RECEPTORS

EXTENSOREXTENSOR

FLEXOR FLEXOR

Renshaw Cell

Ia fromspindlep

Renshaw Cell

Alpha-MotorAlpha MotorNeuron