Neural Messages

These flashcards cover key concepts related to neural messages, including axonal conduction, action potentials, and synaptic transmission.

Axonal conduction is the process by which electrical messages or action potentials move down the axon.

What is axonal conduction?

In the resting state, the inside of the axon is more negative (-70mV) than the outside due to negative protein ions.

What happens during the resting state of a neuron?

An action potential is initiated when receptors on dendrites receive more excitatory signals than inhibitory signals, reaching a threshold of -55mV.

What initiates an action potential in a neuron?

Depolarization occurs when sodium (Na+) gates open, allowing Na+ to rush into the axon, making the inside of the axon more positive (+40mV).

What is depolarization in the action potential process?

Repolarization involves potassium (K+) gates opening, allowing K+ to rush out of the axon, making the inside of the axon more negative.

What does repolarization involve?

Hyperpolarization is when potassium gates stay open too long, causing too much K+ to flow out and making the inside of the axon super negative.

What is hyperpolarization?

The refractory period is when the neuron cannot fire another action potential until it returns to -70mV.

What is the refractory period?

Neurons communicate by releasing neurotransmitters into the synaptic space, which can bind to receptors on the postsynaptic neuron.

How do neurons communicate at synapses?

Excitatory signals are 'go' signals that depolarize the neuron or allow positive ions in.

What are excitatory signals?

Inhibitory signals are 'stop' signals that hyperpolarize the neuron or allow negative ions out.

What are inhibitory signals?

After binding, neurotransmitters are released and may be degraded by enzymes or taken back into the presynaptic neuron by reuptake pumps.

What happens to neurotransmitters after they bind to receptors?