Exam 1: Structure & Function Flashcards
Dendrites
Collect incoming signals from other neurons.
Soma/Cell Body
Where the nucleus resides/integrates information from dendrites.
Axon Terminals
Contains neurotransmitters, optimized for signal ouput
Nucleus
Houses the cell’s genome, the nucleus serves both as the repository of genetic information and as the cell’s control center.
Axon Hillock
Enlargement on cell body, where neurons axon projects away.
-Gathers & integrates information from synapse
Axon
Nerve fiber extension from the soma, allowing communication over long distances.
Axon Terminals
Contain neurotransmitters optimized for signal output.
Sensory Neurons
Convey information from sense organs to the brain, taking many different shapes depending on whether they signal the presence of light or sound or touch and so on.
Motor Neurons
The neurons that trigger movements are large with long axons reaching out to synapse on muscles, causing muscular contractions.
Interneurons
Receive information from other neurons, process it, and pass the integrated information to other neurons.
Unipolar Neurons
Have a single extension, typically identified as an axon for its entire length.
At one end are the branching dendrite-like input zone and integration zone.
Transmit touch and pain information from the body into the spinal chord.
Bipolar Neurons
Have a single dendrite at one end of the cell and a single axon at the other end. Are common in sensory systems, such as vision.
Multipolar Neurons
Have many dendrites and a single axon. Most common type of neuron.
Pre-synaptic
Refers to the “transmitting” side of a synapse.
Postsynaptic
This refers to the region of a synapse that receives and responds to neurotransmitters.
Synapse
The junction between neurons where they communicate with each other.
Vesicle
A small spherical structure that contains molecules of neurotransmitters
Nodes of Ranvier
A gap between successive segments of the myelin sheath where the axon membrane is exposed.
Neurotransmitter
The signaling chemical released from the presynaptic axon terminal that diffuses across the synaptic cleft to alter the functioning of the postsynaptic neuron, which serves as the basis of communication between neurons.
Receptor
A specialized protein, embedded in the cell membrane, that selectively senses and reacts to molecules of a corresponding neurotransmitter.
Oligodendrocytes
A type of glial cell that forms myelin in the CNS.
Schwann Cell
A type of glial cell that forms myelin in the PNS.
Myelin
A fatty insulation around an axon, is formed by glial cells. This sheath boosts the speed at which nerve impulses (action potentials) are conducted.
Microglia
Extremely small motile glial cells that remove cellular debris from injured or dead cells.
Astrocytes
A star-shaped glial cell with numerous processes (extensions) that run in all directions.
NG2 Cells
Possess some functional receptors, and contact neurons at Nodes of Ranvier or via synaptic terminals. Some NG2 cells can even fire action potentials.
Santiago Ramon y Cajal
Discovered that although neurons come very close together, they are not quite continuous with one another. Established the “Neuron Doctrine”
Neuron Doctrine
- Neurons and other brain cells are structurally, metabolically, and functionally independent.
- Information is transmitted through synapses from neuron to neuron.
