In this lesson you will learn about how an electrical signal knowns as an action potential is generated and how it travels along an axon. You will also learn about the presence of chemical messengers known as neurotransmitters and their role in the transmission of signals between neuron at the synapses.
By the end of this lesson, students should be able to
- define hyperpolarization, depolarization, resting stage, graded potential, action potential, Myelin sheath, Schwann cell, Nodes of Ranvier, Saltatory conduction, synapse.
- explain how action potentials are generated at the axon hillock and how they travel along the axon to the synaptic terminal.
- describe what occurs in each of the phases of an action potential including: resting potential phase, depolarization phase, rising phase, falling phase, undershoot and refractory phase.
- recognize all the phases on an action potential diagram.
- explain how an electrical signal triggers the release of neurotransmitters into the synapsis cleft.
- recognize the various components of a chemical synapsis on a diagram and establish the role each component plays.
- list the most common types of neurotransmitters indicating sites where they are produced and their functions.
Let’s examine how an action potential is generated in the video lesson below. Take detailed notes as you watch lesson.
Action Potentials Activity
Watch the animation below on how action potentials are generated in neurons. Next, write down a descriptive narrative of the events needed for an action potential to form in a neuron, using both the information in the video lesson above and in this animation.
This second video lesson below introduces the chemical synapses and neurotransmitters. Watch it and take detailed notes.
Chemical Synapse Activity
Watch the animation below on how information travels from neuron to neuron via a synapse. Next, write down a descriptive narrative of the events needed for a chemical synapse to transmit information between synaptic and postsynaptic neurons, using both the information in the video lesson above and in this animation.