Neurons and Action Potentials

These flashcards cover key concepts and terminology related to neurons and their functions, including neuron structure, action potentials, neurotransmission, and sensory coding.

What is the basic structure that transmits electrical signals in the body?

Neuron.

What are the key components of a neuron?

Cell body, dendrites, and axon.

What type of neurons respond to environmental stimuli?

Sensory neurons.

What part of a neuron receives stimulation from other neurons?

Dendrites.

What is the part of the neuron that conducts nerve impulses?

Axon.

What is the resting potential of most nerve fibers?

Approximately -70 mV.

What occurs during the depolarization phase of an action potential?

The inside of a neuron becomes more positive.

What is the threshold in neuron firing?

The minimum stimulus energy necessary to trigger an action potential.

What defines an action potential?

A rapid increase in positive charge in a nerve fiber that travels down the fiber.

What is the peak size of an action potential?

+40 mV.

What is the refractory period?

The time needed for a nerve fiber to recover from conducting a nerve impulse.

What allows for spontaneous activity in neurons?

Nerve firing that occurs in the absence of environmental stimulation.

What are ions?

Charged molecules, such as sodium (Na+), potassium (K+), and chlorine (Cl-).

What is the significance of sodium channels during an action potential?

They open to allow sodium ions to enter the neuron, increasing membrane potential.

What happens during the falling phase of an action potential?

The neuron becomes more negative as potassium ions leave the cell.

What structures at the end of axons release neurotransmitters?

Terminal buttons.

What is synapse?

A small space between the end of one neuron and the cell body of another neuron.

What is the role of receptor sites in neurotransmission?

They are sensitive areas on the postsynaptic neuron for neurotransmitters to bind to.

What triggers an excitatory response in a neuron?

An increase in firing rate or chance of firing due to neurotransmitter binding.

What defines sensory coding?

How neurons represent various characteristics of the environment.

What is specificity coding?

A type of neural code where different perceptions are signaled by activity in specific neurons.

What is sparse coding?

The idea that a particular object is represented by the firing of a relatively small number of neurons.

What defines population coding?

Representation of a particular object or quality by the pattern of firing of a large number of neurons.

What is modularity in the brain?

The idea that specific areas of the cortex are specialized to respond to specific types of stimuli.

What is neuropsychology?

The study of the behavioral effects of brain damage in humans.

What does fMRI measure?

Brain activity in awake, behaving organisms in response to changes in blood flow.

What is distributed representation?

When a stimulus causes neural activity in different areas of the brain, with the activity being distributed across multiple regions.

What is the mind-body problem?

The challenge of how physical processes translate into perceptual experiences.

How many neurotransmitters are identified in humans?

Over 100.

What leads to an action potential?

A strong enough excitatory signal surpassing the threshold.

What is hyperpolarization?

When the inside of a neuron becomes more negative.

What is the relationship between stimulus intensity and action potential firing rate?

Greater stimulus intensity leads to a faster firing rate.

What occurs once the membrane potential returns to resting levels?

Potassium channels close and the neuron recovers after hyperpolarization.