INTRODUCTION TO

PERIPHERAL NERVOUS SYSTEM

Kaan Yücel M.D., Ph.D.

26. February.2014 Wednesday

Neuron100 billion neurons in the brain share a number of common features:Cell bodymetabolic center of the neuronDendritesreceives connections from other neurons.Axon transmits information to other neuronsPresynaptic terminals

Synapse terminal region of the axon where one neuron forms a connection with another and conveys information through the process of synaptic transmission.

To communicate with the postsynaptic cell, the presynaptic neuron needs to release a chemical messenger.

Neurotransmitters Acetylcholine Memory

Adrenaline Dopamine Reward,

addictionHistamine

Noradrenaline Serotonin Mood

Neuroglia

Non-neuronal supporting cells

Macroglia

Microglia

Ependymal cells

PERIPHERAL NERVOUS SYSTEM

• 12 PAIRS OF CRANIAL NERVES• 31 PAIRS OF SPINAL NERVES• ASSOCIATED STRUCTURES (SUCH AS GANGLIA)

MOTOR SENSORY

SOMATIC NERVOUS SYSTEM

http://www.nature.com/nrn/journal/v4/n7/fig_tab/nrn1141_F1.html

exteroceptorsexternal stimuli (pain, touch, and temperature)

proprioceptionreceptors @tendons, joint capsules, and muscles convey position sense

http://www.med.umich.edu/lrc/coursepages/m1/anatomy2010/html/modules/NS_overview_module/NS_Overview_10.html

interoceptors in visceral organs convey stretch as well as pressure, chemoreception, and pain.

AUTONOMIC NERVOUS SYSTEMSENSORY – AFFERTENT FIBERS

Gyrus & Sulcus & Fissure

SULCI-depressions-DIVIDE THE BRAIN INTO GYRI -elevations- LOBES are MADE UP BY GYRI

Motor homunculusSensory homunculus

Motor homunculusSensory homunculus

Important station that receives the main sensory tracts (except the olfactory pathway).

A station where much of the information is integrated and relayed to the cerebral cortex and many other subcortical regions.

A key role in the integration of visceral and somatic functions.