Neurophysiology and Biopsychology Quiz

Study Notes

Myelination and Neuron Function

Oligodendrocytes in the central nervous system and Schwann cells in the peripheral nervous system are responsible for myelinating neurons.
Myelin functions as an insulating layer that enhances the speed of electrical signal transmission along axons.

Myelinated vs. Unmyelinated Neurons

Myelinated nodes, called nodes of Ranvier, allow for saltatory conduction, where action potentials jump between nodes, speeding up transmission.
Unmyelinated fibers propagate action potentials more slowly and continuously along the entire length of the axon.

Postsynaptic Potentials

During excitatory postsynaptic potential (EPSP), neurotransmitters bind to receptors, causing depolarization and bringing the neuron closer to the action potential threshold.
Inhibitory postsynaptic potentials (IPSPs) cause hyperpolarization, making it less likely for a neuron to fire an action potential.

Neural Integration

Neural integration refers to the summation of EPSPs and IPSPs, determining whether a neuron reaches the threshold for firing an action potential.

Summation Types

Temporal summation occurs when multiple EPSPs are generated at a single synapse in quick succession, leading to a cumulative effect that may trigger an action potential.
Spatial summation involves the simultaneous activation of multiple synapses on a neuron, contributing to the net change in membrane potential.

Neuron Communication

Action potentials are triggered by voltage changes, influenced by the openings and closings of ion channels, particularly sodium and potassium channels.
Synapses play a critical role in neuron communication by allowing neurotransmitter release, facilitating signal transmission between neurons.

Membrane Potential and Ion Channels

The resting membrane potential is typically around -70 mV, maintained by the sodium-potassium pump and ion distribution across the membrane.
Voltage-gated ion channels are essential for action potential initiation and propagation, opening in response to changes in membrane potential.

Action Potential Phases

During the absolute refractory period, a neuron cannot fire another action potential, regardless of stimulus strength, due to inactivated sodium channels.

Multiple Sclerosis

Multiple sclerosis is caused by the immune system attacking myelin, leading to disrupted signal transmission and neurological symptoms.

Description

Test your knowledge on neurophysiology and biopsychology with this quiz! Learn about the basics of neurons, how they communicate through action potentials, and the role of neurochemistry in this process. Challenge yourself and see how well you understand the fascinating world of neuron communication.