AP® Biology: Neuron Structure and Function

What is the usual direction of information flow along a neuron?

What is the membrane of an axon called when it is at rest?

What type of gradient exists across the membrane of a resting axon?

What ions are used by neurons to establish a gradient?

What powers the Na+/K+ pump that maintains the resting membrane potential?

What causes the membrane potential to change in response to a stimulus?

What occurs in depolarization?

What is the phenomenon called when action potentials 'jump' between gaps of unmyelinated axons?

What occurs during repolarization?

What is the junction called across which transmission of a nerve impulse from one neuron to another occurs?

What are the chemical messengers released into the junction at the synapse?

What type of neurotransmitters may decrease the chance of an action potential in the postsynaptic neuron?

What occurs when neurotransmitters bind to receptors embedded in the membrane of the postsynaptic neuron?

What do many drugs, including tetrahydrocannabinol (THC) in marijuana, induce changes in?

What is the neurotransmitter important to short-term memory that THC in marijuana binds to?

Which Big Idea of the AP® Biology Curriculum Framework do the concepts outlined in the section support?

Neuron Signaling

Information flow along a neuron is unidirectional: dendrites -> cell body -> axon.
The membrane of an axon at rest is called the resting membrane.
A concentration gradient exists across the resting axon membrane.
Sodium (Na+) and potassium (K+) ions are used to establish the gradient.
Active transport powers the Na+/K+ pump that maintains the resting membrane potential.
Stimuli trigger changes in the membrane potential.
Depolarization occurs when the membrane potential becomes less negative due to the influx of positively charged ions, primarily sodium ions.
Saltatory conduction describes the "jumping" of action potentials between gaps of unmyelinated axons.
Repolarization is the return of the membrane potential to its resting state, as potassium ions move out of the neuron.
The junction across which transmission of a nerve impulse from one neuron to another occurs is called a synapse.
Neurotransmitters are the chemical messengers released into the junction at the synapse.
Inhibitory neurotransmitters, like GABA, may decrease the chance of an action potential in the postsynaptic neuron.
When neurotransmitters bind to receptors on the postsynaptic neuron's membrane, they trigger a change in the membrane potential of the postsynaptic neuron.
Many drugs, including tetrahydrocannabinol (THC) in marijuana, induce changes in synaptic transmission.
THC binds to cannabinoid receptors in the brain, particularly those involved in short-term memory.
These concepts support Big Idea 1: The process of evolution drives the diversity and unity of life, and Big Idea 2: Biological systems utilize free energy and molecular building blocks to grow, to reproduce, and to maintain dynamic homeostasis.

Test your knowledge of the structure and function of neurons in this AP® Biology quiz. Learn about the flow of information along neurons, the components of eukaryotic cells, and the propagation of action potentials.