Cells of the Nervous System and Resting Membrane Potential

Neuron

Excitable cells transmitting electrical impulses.

Glial Cells

Support cells for neurons.

Soma

Cell body containing nucleus and organelles.

Dendrites

Receive incoming information.

Axon

Transmits action potentials.

Axon Hillock

Initiates action potentials.

Axon Terminal

Releases neurotransmitters.

Interneuron

Connects neurons within brain and spinal cord.

Motor Neurons

Carry signals from CNS to muscles.

Sensory Neurons

Transmit signals from periphery to CNS.

Afferent Neurons

Another name for sensory neurons.

Unipolar Neurons

Sensory neurons with single axon structure.

Multipolar Neurons

Motor neurons with multiple dendrites.

Neuroglia

Supportive cells in the nervous system.

Astrocytes

Provide metabolic support to neurons.

Microglia

Remove dead cells and bacteria.

Ependymal Cells

Line cavities and produce cerebrospinal fluid.

Oligodendrocytes

Myelin-producing cells in CNS.

Schwann Cells

Myelinating cells in PNS.

Resting Membrane Potential (RMP)

Charge distribution across neuron membrane.

Polarized Membrane

Negatively charged inside, positively outside.

Na+/K+ ATPase

Pump maintaining ion concentration gradients.

Depolarization

Less negative membrane potential change.

Hyperpolarization

More negative membrane potential change.

Repolarization

Return to resting membrane potential.

Ion Channels

Membrane proteins allowing ion passage.

Passive Channels

Always open channels in neuron.

Ligand-gated Channels

Open in response to ligand binding.

Voltage-gated Channels

Open in response to membrane potential change.

Local Potentials

Sub-threshold changes in membrane potential.

Graded Potentials

Local potentials that vary in size.