Physiology, Hormones, and Neurons

These flashcards cover various aspects of the physiology of neurons, including their structure, function, communication, and the effects of different factors on neuronal activity.

Neuron

A nerve cell that receives and sends electrical signals.

Glial cells

Non-neuronal cells that support and protect neurons.

Central Nervous System (CNS)

The part of the nervous system consisting of the brain and spinal cord.

Peripheral Nervous System (PNS)

The part of the nervous system consisting of nerves that connect the CNS to the rest of the body.

Membrane Potential

The difference in charge across the cell membrane, expressed in millivolts.

Resting Membrane Potential

The membrane potential of a neuron at rest, typically around -60 mV.

Depolarization

A decrease in membrane potential, making the inside of the cell less negative.

Hyperpolarization

An increase in membrane potential, making the inside of the cell more negative.

Action Potential

A rapid change in membrane potential that propagates along the axon.

Na+/K+ pumps

Mechanisms that move Na+ out of the cell and K+ into the cell to establish concentration gradients.

Synapse

The junction between two neurons where neurotransmitters are released.

Excitatory Post-Synaptic Potential (EPSP)

A neurotransmitter-induced change that makes a neuron more likely to fire an action potential.

Inhibitory Post-Synaptic Potential (IPSP)

A neurotransmitter-induced change that makes a neuron less likely to fire an action potential.

Voltage-gated Na+ channels

Channels that open in response to membrane depolarization, allowing Na+ to enter the neuron.

Voltage-gated K+ channels

Channels that open in response to depolarization, allowing K+ to leave the neuron.

Saltatory Conduction

The process by which action potentials jump from node to node along a myelinated axon.

Myelin Sheath

An insulating layer around axons that speeds up electrical signals.

Oligodendrocytes

Glial cells that form the myelin sheath in the Central Nervous System.

Schwann cells

Glial cells that form the myelin sheath in the Peripheral Nervous System.

Astrocytes

Glial cells that support neurons and help maintain the blood-brain barrier.

Microglia

Glial cells that act as immune cells in the Central Nervous System.

Action Potential Stages

1. Depolarization to threshold, 2. Complete depolarization, 3. Repolarization, 4. Restoring resting potential.

Absolute Refractory Period

The period during which a neuron cannot fire another action potential.

Relative Refractory Period

A period following an action potential during which a neuron can fire again, but only with stronger-than-normal stimulation.

Neurotransmitter

Chemical messengers released by axon terminals that transmit signals between neurons.

Calcium Channels

Channels that open to allow Ca2+ into the neuron, triggering neurotransmitter release.

Neuronal Communication Overview

The process of signal transmission between neurons, involving excitation, action potentials, and synaptic transmission.

Dendrites

Projections that receive signals from other neurons.

Axon

The part of a neuron that transmits electrical signals away from the cell body.

Signal Integration

The process by which a neuron sums multiple inputs to determine if an action potential should be fired.

Neurotoxins

Substances that disrupt neuronal function.

Tetrodotoxin

A neurotoxin that blocks voltage-gated Na+ channels, preventing action potentials.

Dendrotoxin

A neurotoxin that blocks voltage-gated K+ channels, leading to prolonged depolarization.

Resting Potential Restoration

The process by which a neuron's membrane potential returns to its resting state after an action potential.

Neuron Structure

The physical configuration of a neuron, including its cell body, dendrites, and axon.

Neural Networks

Interconnected groups of neurons that process and transmit information.

Multiple Sclerosis (MS)

A disease characterized by the degeneration of the myelin sheath in the CNS.

Concentration Gradient

A difference in the concentration of ions across a membrane.

Receptor Sites

Locations on dendrites where neurotransmitters bind to trigger physiological responses.

Neurophysiology

The study of the functions and activities of the nervous system.

Feedback Mechanisms

Processes by which the output of a system regulates its own activity.

Neural Plasticity

The ability of the nervous system to adapt and change in response to experience or injury.

Homeostasis

The maintenance of a stable internal environment within an organism.

Myelination

The process of forming a myelin sheath around a neuron.

Axon Terminals

The end part of an axon where neurotransmitters are released.