THE STRUCTURE AND FUNCTION OF NEURONS

100 BILLION NEURONS

80% LOCATED BRAIN

TRANSMIT SINGLANS ELECTRICALLY / CHEMICALLY

PROVIDE NERVOUS SYSTEM PRIMARY MEANS COMMUNICATION

MOTOR: CONNECT CNS TO EFFECTORS SUCH AS MUSCLES / GLANDS: SHORT DENDRITES / LONG AXONS

SENSORY: CARRYS MESSAGE PNS TO CNS. LONG DENDRITES / SHORT AXONS

RELAY: CONNECT SENSORT NEURONS TO MOTOR / OTHER RELAY. SHORT DENDIRTES / SHORT AXONS

VARY SIZE FROM MM TO M LONG

CELL: NUCLEUS (DNA) / DENDRITES (CARRY NERVE IMPULSES NERUONS TOWARDS CELL BODY) 

AXON: CARRIES IMPULSES AWAY. COVERED FATTY LAYER MYELIN SPEED UP ELECTRICAL TRANSMISSION

MYELIN SHEATH CONTRINOUS WOULD SLOW DOWN ELECTRICAL IMPULSE - SEGMENTED BY GAPS NODES CALLED RANVIER

RANVIER - SPEED UP BY FORCING JUMP GAPS ACROSS AXON

NEURON RESTING STATE CELL NEGATIVLEY CHARGED COMPARED OUTSIDE

NEURON ACTIVATED STIMULUS CELL POSTIVLEY CHARGED SPLIT SECOND CAUSING ACTION POTENTIAL OCCUR

CREATES ELECTRICAL IMPULSE TRAVELS DOWN AXON TO NERUON

STIMULUS E.G. HAMMER HITS KNEE

DETECTED SENSE ORGANS PNS CONVEY MESSAGE ALONG SENSORY NEURON

MESSAGE REACHES CNS CONNECTS RELAY NEURON

TRANSFER MESSAGE TO MOTOR NERUON

CARRIES MESSAGE MUSCLE - CAUSES CONTRACT - KNEE MOVE

NEURONS COMMUNICATE GROUP NEURAL NETWORKS

NEURON SEPERATED TINY GAP SYNAPSE

SIGNALS WITHIN NEURONS TRANSMITTED ELECTRICALLY - THO CHEMICALLY ACCROSS SYNAPSE

ELECTRICAL IMPULSE REACHES END NEURON TRIGGERS RELEASE NEUROTRANSMITTER TINY SACS SYNAPTIC VESCILES

CHEMICALS DIFFUSE SYNAPSE NEXT NEURON CHAIN

CROSS GAP TAKEN BY POSTSYNAPTIC RECEPTOR SITE

CHEMICAL MESSAGE CONVERTED BACK ELECTRICAL IMPULSES

EACH NEUROTRANSMITTER SPECIFIC MOLECULAR STRUCTURE FIT POST SYNAPTIC RECEPTOR SITE

NEUROTRANSMITTERS EXCITATORY OR INHIBITORY EFFECTS

SEROTONIN CAUSES INHIBITION RECIEVING NEURON RESULT NEURON NEGATIVELY CHARGED LESS LIKELY FIRE

ADRENLINE CAUSES EXCIATION POST-SYNAPTIC NEURON INCREASING POSITIVE CHARGE - MORE LIKELY FIRE

NEUROTRANSMITTERS EXCITATORY OR INHIBITORY EFFECTS

SEROTONIN CAUSES INHIBITION RECIEVING NEURON RESULT NEURON NEGATIVELY CHARGED LESS LIKELY FIRE

ADRENLINE CAUSES EXCIATION POST-SYNAPTIC NEURON INCREASING POSITIVE CHARGE - MORE LIKELY FIRE