The Spinal Cord

cranial nerves- 12 pr

spinal nerves- 31 pr

The Spinal CordThe Spinal Cord

ventral root

pia mater

dura mater

arachnoid

grey matter

dorsal root

white matter

spinal nerves

The Spinal CordThe Spinal Cord

spinal cord

spinal nerve

vertebra

Nerve Pathways into the Spinal Cord

Nerve Pathways into the Spinal Cord sensory

pathway

motor pathway

Neuron-To-Neuron TransmissionNeuron-To-Neuron Transmission

synapses

• T3-T12• 11 intercostal nerve• 1 subcostal nerve

Functional Divisions of the Peripheral Nervous System

Afferent Division– Sensory (advances) neuron –

goes toward CNSEfferent Division

– Motor (exits) neuron- leaves CNS– Somatic Nervous System– Autonomic Nervous System

Spinal Reflex Arc

Spinal Reflex Arc

patellar ligament

stretch receptor

motor neuron

sensory neuron

motor neuron

interneuron