Central Nervous System Communication: Neurons and Glia

Central Nervous System Communication: Neurons and Glia


Cells/structures Types Functions Features
Neurons Sensory neurons Transform physical energy -> sense messages -> the brain Compose the afferent tracts of the nervous system
Motor neurons Transmit information from the brain -> muscles, organs Compose the efferent tracts of the nervous system
Interneurons Transmit communications between neurons Most plentiful in the brain
Glia/glial cells: supporting cells (composed mostly of fat) Structural support
Faster communications between neurons, e.g., via myelin
Healing from injuries and infections
Cleaning of the wastes and dead neurons



Gray Matter and White Matter


Parts Cells/structures
Gray matter Neuron
White matter Axon
Unmyelinated axon



Structures and Functions of Neurons


Structures Substructures Functions
Cell membrane Holds the cell
Nucleus Chromosomes, genetic materials Growth of nervous tissues
Cell body/soma Organelles (Mitochondria, Golgi bodies) Protein production, metabolism, waste excretion
Dendrites Receptors Receiving chemical messages
Axons Myelin (to speed transmission), nodes of Ranvier (gaps in the myelin) Sending electronic signals
Synapses (gaps between the (sending) axon and the (receiving) dendrite) Presynaptic terminal, vesicles with neurotransmitters Transmission across the synapse to the receptors



The Action Potential of Neurons



Functions States Details Features
Resting potential No communication, polarization Internal charge – negative; surrounding area – positive
Action potential Depolarization Firing; positive charge -> synapse All-or-nothing (with the stimulus threshold)
Refractory period (resting); hyperpolarized
Synaptic transmission of neurotransmitters ->reuptake -> recycled
This entry was posted in Nervous System and tagged , , , , , , , . Bookmark the permalink.

Leave a Reply