Introduction to Brain and Behavior – Section 3.1: The Nervous System's Functional Units

Vocabulary flashcards covering the cells of the nervous system, neuron structure, glial cells, membrane biology, and basic protein synthesis.

Golgi method (Golgi staining)

Silver staining technique that reveals individual neurons in tissue, supporting the neuron doctrine.

Neuron doctrine

Idea that neurons are discrete units that transmit signals, not a continuous nerve net.

Brainbow

Modern method using fluorescent proteins to visualize individual neurons and trace their connections.

Neuron

The basic functional cell of the nervous system that transmits information.

Glia

Non-neuronal cells that support, nourish, insulate, and repair neurons; outnumber neurons.

Astrocyte

Star-shaped glial cell that nourishes neurons, helps form the blood-brain barrier, and interacts with blood vessels.

Microglial cell

Glial cell that acts in CNS defense and debris cleanup; small and derived from blood.

Oligodendroglial cell (oligodendrocyte)

Glial cells in the CNS that form myelin around axons.

Schwann cell

Glial cells in the peripheral nervous system that form myelin around peripheral nerves.

Ependymal cell

Glial cell that moves cerebrospinal fluid.

Blood-brain barrier

Barrier formed by tight junctions in brain vessels; astrocyte end feet help regulate nutrient entry.

Membrane

Phospholipid bilayer that encloses the cell, separating intracellular from extracellular fluids.

Nucleus

Structure containing chromosomes and genetic material.

Mitochondrion

Organelle that provides energy for the cell.

Ribosomes

Sites where proteins are synthesized.

Endoplasmic reticulum

Membrane network where proteins are assembled and transported.

Golgi body

Organelle that packages proteins for transport to their destinations.

Lysosomes

Vesicles containing enzymes that digest waste material.

Dendrite

Neuron extension that collects information from other cells.

Dendritic spine

Small protrusion on a dendrite that increases surface area for synapses.

Soma (cell body)

The core region of a neuron containing the nucleus and cytoplasm.

Axon

Extension that transmits information from the cell body to other neurons.

Axon hillock

Junction of soma and axon where the action potential begins.

Axon collaterals

Branches of an axon.

Terminal button

Knob at the tip of an axon that conveys information to other neurons; also called end foot.

Synapse

Gap between two neurons where communication occurs.

Presynaptic terminal

End point of an axon where neurotransmitters are released.

Postsynaptic neuron

Neuron that receives chemical transmission from a nearby neuron.

Nodes of Ranvier

Gaps in the myelin sheath along an axon that facilitate rapid signal conduction.

Myelin sheath

Glial insulation around axons that speeds transmission; produced by Schwann cells in the PNS and oligodendrocytes in the CNS.

Sensory neuron (afferent)

Neuron that carries information from sensory receptors to the CNS.

Interneuron

Association neuron that connects neurons within the CNS.

Motor neuron (efferent)

Neuron that sends signals from the CNS to muscles.

Channel

Opening in a membrane protein that allows ion passage.

Gate

Membrane protein that opens or closes to regulate passage.

Pump

Membrane protein that actively transports substances across the membrane.

Phospholipid bilayer

Two-layer cell membrane with hydrophilic heads facing water and hydrophobic tails inward.

Hydrophilic heads

Water-attracting parts of phospholipids facing the aqueous environment.

Semipermeable

Membrane property that allows some substances to pass while blocking others.

Chromosome

Double-stranded DNA molecule that carries genetic information.

DNA

Deoxyribonucleic acid; molecule encoding genetic information.

Transcription

Process of copying a gene’s DNA sequence into mRNA.

mRNA

Messenger RNA that carries genetic information from DNA to ribosomes.

Translation

Process by which ribosomes read mRNA and assemble amino acids into a protein.

Amino acid

Building blocks of proteins.

Polypeptide chain

A chain of amino acids that folds into a protein.

Protein

Molecule that performs a wide range of cellular functions; determined by amino acid sequence and folding.

Protein folding

Process by which a protein attains its functional three-dimensional shape.