Neurons and Neuroglia Overview

Neurons are cells that transmit information electrically and chemically in the nervous system. They have a cell body, dendrites, and an axon.

Short, branched extensions of a neuron that receive signals from other neurons.

A long, single extension of a neuron that transmits electrical signals (action potentials) to other cells.

The central part of a neuron containing organelles necessary for the neuron's survival.

A neuron with one dendrite and one axon.

A neuron with a single extension that acts as both dendrite and axon.

Part of the body that uses electrical/chemical processes in cells to manage sensory/motor actions

Electrical signal transmitted along a neuron's axon.

Neurons with multiple branching dendrites and a single axon.

Support neuronal function and is about 50% of the brain's cell population.

Regulate the chemical environment surrounding neurons.

Myelinating glial cells in CNS/PNS respectively. Myelinates neurons.

Phagocytic cells that engulf cell debris in the brain.

Actively transports sodium out of and potassium into the cell against their concentration gradients.

The membrane potential at which the net movement of an ion across the membrane is zero.

Membrane potential at which the movement of potassium ions is equal in both directions; approximately -90mV.

Membrane potential at which the movement of sodium ions is equal in both directions; approximately +60mV.

The steady voltage difference across the cell membrane in a resting neuron; primarily influenced by potassium concentration gradients, and slightly less by sodium.

Proteins in the cell membrane that allow ions to passively move across the membrane.

The movement of ions down their concentration gradients across the membrane.

Changes in ion movement across the plasma membrane create electrical signals.

A tiny gap between the axon terminal of one neuron and the dendrite of another, where chemical communication occurs.

Small sacs within the axon terminal that store and release neurotransmitters into the synaptic cleft.

The process by which neurotransmitters are released from synaptic vesicles into the synaptic cleft.

Ions that trigger the release of neurotransmitters from synaptic vesicles.

Channels in the axon terminal that open when a neuron receives a signal, allowing calcium ions to flow in.

A chemical messenger released from the axon terminal of a neuron that transmits information to the next neuron.

A protein on the postsynaptic membrane that binds to neurotransmitters, triggering a response in the receiving neuron.

A temporary depolarization of the postsynaptic membrane, making it more likely for the neuron to fire an action potential.

A temporary hyperpolarization of the postsynaptic membrane, making it less likely for the neuron to fire an action potential.

The process of combining multiple EPSPs and IPSPs to determine whether a neuron will fire an action potential.

Many neurons synapsing on one neuron.

One axon branching to synapse on many neurons.

The pump has 3 high-affinity binding sites for sodium ions (Na+) and 2 low-affinity binding sites for potassium ions (K+).

Gaps in the myelin sheath of an axon, where action potentials are regenerated. Sodium and potassium channels are concentrated in these areas.

Slow propagation of an action potential along an unmyelinated axon, where the signal spreads continuously.

Fast propagation of an action potential along a myelinated axon, where the signal jumps from node to node.

Junction between two neurons where information is transmitted from one neuron to another.

A type of synapse where neurons are connected directly by gap junctions. This type is relatively uncommon in humans.

A type of synapse where chemical messengers called neurotransmitters transmit information from one neuron to another.