1.1 Cellular Components

Flashcards covering key vocabulary and concepts related to neurons, glial cells, and neural circuits.

Glial Cell

Supportive cells in the nervous system that assist neurons and maintain homeostasis.

Oligodendrocyte

A type of glial cell in the Central Nervous System (CNS) that forms myelin sheaths.

Astrocyte

A type of glial cell in the CNS that forms support for the CNS and blood-brain barrier, secretes neurotrophic factors and takes up K+ neurotransmitters.

Microglia

Immune cells in the CNS that act as scavengers to clean up debris.

Dendrites

Extensions of a neuron that receive signals from other neurons.

Axon

The long, slender projection of a neuron that conducts electrical impulses away from the cell body.

Synapse

The junction between two neurons where communication occurs.

Excitatory Neuron

A neuron that increases the activity of the target neuron when activated.

Inhibitory Neuron

A neuron that decreases the activity of the target neuron when activated.

Tripartite Synapse

A synapse structure involving a pre-synaptic neuron, a post-synaptic neuron, and an astrocyte. The astrocyte acts as a gliotransmitter, which increases the activity of the adjacent neurons and astrocyte.

Gliotransmitter

Chemical transmitters released by astrocytes that communicate with neurons.

Neurovascular Unit

The functional relationship between neurons, astrocytes, and blood vessels that regulates blood flow. Increase in neuronal activity leads to a increase in arterial dilation and therefore increase in blood flow.

Feedback Neural Circuit

A neural circuit where the output of a neuron influences its own activity.

Convergent Neural Circuit

A neural pathway where multiple neurons synapse onto a single neuron.

Divergent Neural Circuit

A neural pathway where a single neuron synapses onto multiple other neurons.

What are the key classifications of neurons?

Morphology (structure), Location, Function (phenotype - e.g. excitatory), Chemical (phenotype - e.g. releases Acetylcholine, therefore Cholinergic)

What are the common regions of neurons?

Common regions of neurons include the dendrites, cell body (soma), axon hillock, axon, and synapse.

What is the relationship between glial and non-glial cells?

Glial cells support and protect neurons (non-glial cells) by providing structural support, insulation, and nutrients.

What is the importance of glia within the CNS?

As the complexity of the nervous system increases (e.g. from mouse to human), the ratio of astrocytes to enurons increases with complexity of the nervous system.

What is meant by an excitatory or inhibitory neuron?

Excitatory neurons increase the likelihood of the firing of an adjacent neuron, while inhibitory neurons decrease that likelihood.

How do you determine the output of a simple neural circuit?

The output of a simple neural circuit is determined by the combined excitatory and inhibitory inputs it receives, influencing the firing rate of the final output neuron.

What are the features of some complex neural circuits?

Features of complex neural circuits include synaptic plasticity, feedback loops, and multiple pathways influencing the overall output.

What is spatial buffering with regard to astrocytes?

Astrocytes prevent potassium poisoning connecting with each other by gap junctions.

Gap Junctions

Spaces between adjacent cells (astrocytes) that buffer extreme concentrations.