Nervous Tissue and Membrane Potentials

Flashcards covering key terms and concepts from lecture notes on nervous tissue, membrane potentials, and action potentials.

Neuron

Excitable nerve cell that initiates and transmits nerve impulses.

Glial cells

Non-excitable cells that support and protect neurons.

Membrane potential

Voltage measured across a membrane, reflecting the separation of charges.

Resting Membrane Potential

The membrane potential of a neuron when not actively transmitting signals, typically around -70mV.

Action potential

A significant fluctuation in membrane voltage involving depolarization and repolarization.

Graded potential

Local changes in membrane potential that vary in size and can lead to action potentials.

All-or-None Principle

The principle stating that once a threshold is reached, a neuron will fire an action potential fully, or not at all.

Sodium-Potassium Pump

A key pump in neurons that maintains ion concentration gradients by actively transporting Na+ out and K+ into the cell.

Excitatory postsynaptic potential (EPSP)

A graded potential that depolarizes the membrane towards the action potential threshold.

Inhibitory postsynaptic potential (IPSP)

A graded potential that hyperpolarizes the membrane away from the action potential threshold.

Neurolemmocyte

Also known as Schwann cell, a type of glial cell that wraps around axons to form myelin sheath.

Voltage gated channels

Channels that open or close in response to changes in membrane potential.