Communication Within Neurons

These flashcards cover the key concepts related to the communication processes within neurons as described in the lecture notes.

What are ions and how are they classified?

Ions are charged atoms that can be positively charged (e.g., Na+) or negatively charged (e.g., Cl-).

What is the resting potential of a neuron?

The resting potential is -70 mV, indicating that the inside of the neuron is more negative than the outside.

What occurs during depolarization in a neuron?

During depolarization, if positive charges are injected into the cell, the internal negativity decreases, reducing polarization.

What is hyperpolarization?

Hyperpolarization occurs when positive charges are moved out of the neuron, making the inside more negative and increasing polarization.

What is the threshold potential for action potential?

The threshold potential is -55 mV, which triggers the action potential.

What is the function of sodium-potassium pumps in neurons?

Sodium-potassium pumps actively transport sodium ions out of the cell and potassium ions into the cell to maintain ion concentration and resting potential.

What happens to sodium channels during an action potential?

Sodium channels open when the membrane potential reaches -55 mV, allowing Na+ ions to flood into the cell, leading to depolarization.

What are excitatory and inhibitory postsynaptic potentials?

Excitatory postsynaptic potentials (EPSP) cause depolarization, while inhibitory postsynaptic potentials (IPSP) cause hyperpolarization of the postsynaptic membrane.

What is the significance of the all-or-nothing principle in action potentials?

The all-or-nothing principle states that action potentials occur fully or not at all; they do not diminish in strength.

What is neural integration at the axon hillock?

Neural integration is the summation of all postsynaptic potentials to determine whether an action potential will occur.

How are neurotransmitters released at the synapse?

Neurotransmitters are released by exocytosis when action potentials open voltage-gated calcium channels, allowing Ca2+ to enter the axon terminal.

What is the role of receptors on the postsynaptic membrane?

Receptors bind neurotransmitters and facilitate the opening of ion channels in the postsynaptic membrane, allowing ions to flow.

What happens when the membrane potential is changed at the axon hillock?

If the membrane potential reaches the threshold, an action potential is generated; if not, the signal may dissipate.