Organization
This part of the nervous system incudes the brain and spinal cord.
What is the Central Nervous System (CNS)?
This is the primary nervous system communicator that carries signals.
What is a neuron?
The normal resting membrane potential of a neuron is approximately this value.
What is -70 mV?
Action potentials are described as this type of event, meaning they either happen fully or not at all.
What is all-or-none?
A functional connection between a neuron and another cell is called this.
What is a synapse?
This division gathers sensory information and sends instructions outside the brain and spinal cord.
What is the Peripheral Nervous System (PNS)?
These cells provide nutrients, insulation, and structural support to neurons.
What are neuroglia (glial cells)?
This property of neurons refers to their ability to respond to stimuli and generate an action potential.
What is excitability?
This is the minimum intensity required to trigger an action potential.
What is threshold?
This type of synapse uses neurotransmitters to transmit signals.
What is a chemical synapse?
This subdivision of the PNS controls voluntary movement like walking or raising your hand.
What is the Somatic Nervous System?
These CNS glial cells act like macrophages and remove dead or dying neurons.
What are microglia?
This phase occurs when fast voltage-gated Na⁺ channels open and Na⁺ enters the cell.
What is depolarization?
These channels open when a neurotransmitter binds to them.
What are ligand-gated channels?
When an action potential reaches the axon terminal, these channels open first.
What are voltage-gated Ca²⁺ channels?
This division is responsible for fight-or-fight responses.
What is the Sympathetic division?
These PNS cells wrap around axons to form myelin in a 1:1 ratio.
What are Schwann cells?
This phase occurs when K⁺ leaves the cell through slow voltage-gated channels.
What is repolarization?
These channels open in response to changes in membrane potential.
What are voltage-gated channels?
When an action potential reaches the axon terminal, the change in membrane potential opens these specific voltage-gated channels.
What are voltage-gated Ca²⁺ (calcium) channels?
This division conserves energy and promotes rest and digest functions.
What is the Parasympathetic division?
These CNS cells form myelin and can myelinate multiple axons.
What are oligodendrocytes?
During this phase, the membrane potential becomes more negative than resting membrane potential.
What is hyperpolarization?
During this refractory period, no second action potential can occur.
What is the absolute refractory period?
After neurotransmitter binds to receptors on the postsynaptic membrane, this type of potential is produced.
What is a graded potential?