Cogs17 Neurobiology of Cognition Lecture 2a: Structure & Function of Cells in the Nervous System

A set of flashcards covering key vocabulary and concepts related to the structure and function of cells in the nervous system, beneficial for exam preparation.

Soma

The cell body of a neuron, containing the nucleus and organelles.

Cytoplasm

The fluid inside a cell.

Extracellular Fluid

The fluid outside a cell.

Nucleus

The organelle where DNA is stored.

Ribosomes

The site of protein production in a cell.

Mitochondria

Organelles that produce ATP, providing energy for cell functions.

Membrane

A double-layered wall formed by lipids that controls permeability.

Glial Cells

Non-neural cells in the nervous system that support and protect neurons. They have many functions.

Astrocytes

Type of glial cell that provides nutrients to neurons and maintains the blood-brain barrier.

Microglia

Glial cells that act as the immune system of the brain, removing toxic materials.

Myelination

The process of insulating axons to increase the speed of nerve impulses.

Dendrites

Elongated structures that receive incoming signals from other neurons.

Axon

The elongated structure that transmits outgoing signals from a neuron.

Action Potential

A rapid change in membrane potential that allows neurons to 'fire' via Ionic Conduction

Where does Action Potential start?

Starting at Axon Hillock (where Axon joins Soma), Voltage-activated Na+ gates open

Depolarization

The process during an action potential where the inside of the neuron becomes more positive.

What reverses polarization?

Na+ gates open, Na+ rushes in

What happens when depolarization reaches Terminal

Ca++ gates there open & Ca++ enters cell, which influxes Neurotransmitter release

What Restores resting potential

Sodium-Potasium Pump

Refractory Period

A period after an action potential during which a neuron cannot fire again.

All-or-None Law

The principle that an action potential will either occur fully or not at all.

Myelination and Saltatory Conduction

The process that allows action potentials to jump between nodes, increasing speed.

Electrical Conudction

Flow of electron along myelinated segment

Saltatory

Jumping” Nerve Impulse in effect “jumps” from node to node as it is propagated along axon

MS (Multiple Sclerosis)

Disease destroys myelin, causing

Graded Potentials

Changes in membrane potential that vary in amplitude and do not always lead to action potentials.

Local Neurons

Neurons with short axons or no axons that communicate only with adjacent cells.