Neurons and Synapses

Types of nervous systems

Central nervous system and peripheral nervous system

Neuron

Cell body sending axons and receiving dendrites

Distribution of ions

Neuron at rest differs from neuron transmitting pulse

Neuron at rest

carries negative charge ready to be used

Depolarization

Na gates open and immediately close to let some Na ions get in

When does depolarization occur

When a Stimulus/signal arrives

Myelin sheath

Fatty neuroglia wrap around axons

Nodes of ranvier

Gaps with high density of sodium channel

Synapse

Non physical junction when a neuron with another cell

What does synapse trigger

Release of neurotransmitters from synaptic terminal

Synaptic Transmission

Presynaptic (sends message), postsynaptic (receives), synaptic cleft (space between neurons)

Last event in a synapse

Depolarization causes Ca to enter synaptic terminal and open Na channels