Physiology Action Potential Quiz

Study Notes

Neurons consist of a cell body (soma) containing the nucleus and ribosomes for protein synthesis.
Processes include dendrites and axons that facilitate communication between neurons.
Dendrites are short branches that receive signals; their branching increases surface area for signal reception.
Axons, longer than dendrites, transmit signals to other neurons and connect at the Axon Hillock.
Collaterals are branches of the axon, enhancing the neuron’s functional influence.
Axon terminals are responsible for releasing neurotransmitters into the synaptic cleft.

Electrochemical Potential Difference and Equilibrium Potential are crucial for nerve function.
Resting Membrane Potential is established by ion distribution across the membrane.

Graded potentials are local changes in membrane potential that vary in amplitude and can initiate action potentials.
Types of graded potential include depolarization and hyperpolarization, with properties such as summation effects.

Action potentials are rapid changes in membrane potential that propagate along axons.
These are generated at the Axon Hillock and involve voltage-gated ion channels influencing phases of depolarization and repolarization.
The refractory period follows an action potential, preventing immediate re-excitation.

Threshold potential is the minimum level of stimulation required to trigger an action potential.
Resting membrane potential stabilizes the neuron before it responds to stimuli.

Synapses are junctions where neurons communicate through neurotransmitter release.
Types of synaptic transmissions include excitatory and inhibitory actions influencing postsynaptic potentials.
Presynaptic vesicles contain neurotransmitters that fuse with the membrane for release.

Myelin sheath around axons increases conduction speed by enabling saltatory conduction, where action potentials jump between nodes of Ranvier.
Increased degrees of axon branching result in a broader sphere of influence for signal transmission.