Lecture Notes on Neuron Function & Action Potentials

These flashcards cover key concepts related to neuron function, ion gradients, action potentials, synaptic transmission, and important definitions.

Where is sodium more concentrated in a resting state, inside or outside the cell?

Sodium is more concentrated outside the cell.

Where is potassium more concentrated in a resting state, inside or outside the cell?

Potassium is more concentrated inside the cell.

What is the charge of chloride ions?

Chloride ions have a negative charge.

What are the three types of gated channels in cell membranes?

The three types are: chemically gated, voltage-gated, and mechanically gated channels.

What causes the depolarization of a neuron?

Depolarization occurs due to the influx of sodium ions into the cell.

What does the term 'hyperpolarization' refer to in neuronal activity?

Hyperpolarization refers to the membrane potential becoming more negative than the resting membrane potential.

What is the typical resting membrane potential of a neuron?

The typical resting membrane potential of a neuron is around -70 mV.

What is 'threshold' in the context of action potentials?

Threshold is the minimum change in membrane potential that must be reached to trigger an action potential, usually around -55 mV.

What is the 'all or none' principle in action potentials?

The all or none principle states that an action potential will occur fully or not at all, depending on whether the threshold is reached.

What is the role of calcium ions in synaptic transmission?

Calcium ions trigger the exocytosis of neurotransmitters at the synaptic junction.

Define the difference between excitatory and inhibitory post-synaptic potentials.

Excitatory post-synaptic potentials (EPSPs) bring the membrane closer to threshold, while inhibitory post-synaptic potentials (IPSPs) move the membrane further from threshold.

What are the nodes of Ranvier?

Nodes of Ranvier are gaps in the myelin sheath where action potentials are regenerated in myelinated neurons.

What is the primary difference between graded potentials and action potentials?

Graded potentials are localized changes in membrane potential that vary in magnitude, while action potentials are uniform and propagate along the neuron.

What happens at the peak of an action potential?

At the peak of an action potential, sodium channels close and potassium channels open, leading to repolarization.

What neurotransmitter is released at the neuromuscular junction?

Acetylcholine is the neurotransmitter released at the neuromuscular junction.