The action potential

• What does the action potential refer to in neurons?


  It refers to the method that nerve impulses pass down the axon to stimulate the release of neurotransmitters.
• What triggers an action potential in a neuron?


  A change in the electrical potential of the neuron itself triggers an action potential.
• Do all action potentials have the same voltage?


  Yes, all action potentials have the same voltage.
• What factors affect the speed of action potential travel?


  The presence of myelin sheath affects the speed of action potential travel.
• What is the resting membrane potential of a neuron?


  About -70 mV.
• What does a resting membrane potential of -70 mV indicate?


  It indicates that there is a slight negative charge inside the neuron in relation to the outside.
• What happens when a neuron receives a chemical message?


  It can stimulate an excitatory postsynaptic potential or an inhibitory postsynaptic potential.
• What is the effect of excitatory postsynaptic potential on a neuron?


  It slightly depolarizes the neuron, reducing the charge.
• What is the effect of inhibitory postsynaptic potential on a neuron?


  It hyperpolarizes the neuron, increasing the charge.
• What is the term used for the speed at which a neuron sends out signals?


  Firing rate.
• What is meant by upstream and downstream in neuronal signaling?


  Upstream refers to the sending neuron, while downstream refers to the receiving neuron.
• How does the firing rate change in a neuron?


  It changes based on the balance of excitatory and inhibitory messages received.
• What triggers an action potential in a neuron?


  When the neuron's charge reaches approximately +55 mV.
• What happens when an action potential is triggered?


  An impulse is sent along the axon of the neuron towards the axon terminals.
• What are the key components of action potential in neurons?


  • Method for nerve impulses to pass down the axon
  • Triggered by a change in electrical potential
  • All action potentials have the same voltage
  • Speed depends on the presence of myelin sheath
  • Resting membrane potential is about -70 mV
  • Can be stimulated by excitatory or inhibitory messages
  • Action potential triggered at approximately +55 mV
• What are neurotransmitters?


  Chemical messengers that transmit signals across a synapse.
• What is depolarization in the context of neurons?


  It is the process of reducing the charge inside the neuron, making it less negative.
• What is hyperpolarization in the context of neurons?


  It is the process of increasing the charge inside the neuron, making it more negative.
• How does the myelin sheath affect action potential propagation?


  It increases the speed of action potential travel along the axon.