Chemical Beginnings
Early organisms relied on this physical process, where molecules move from high to low concentration, to pass signals.
What is Diffusion?
The major benefit of switching from chemical diffusion to electrical signals was a massive decrease in this "time."
What is reaction time?
Centralization means that nerve cells began clustering toward a singular section of the body to form this main organ.
What is the brain?
Closed-loop systems allow an organism to receive feedback about its own _________.
What is performance(or behavior)?
True or False: Early chemical-based nervous systems allowed animals to move and react much faster than modern animals do.
What is False?
Because diffusion is so slow, early life was severely limited in this physical attribute.
What is speed(or mobility)
These specialized, elongated cells are responsible for carrying rapid electrical impulses throughout the body.
What are neurons?
Instead of being scattered evenly across the body like a net, centralized nerves are packed tightly together in this system.
What is the Central Nervous System?
Before closed-loop systems, an entire species had to rely on this multi-million-year process to change its behavior.
What is evolution(or natural selection)?
The InformedHealth article notes that this specific part of the neuron acts like an antenna to receive incoming signals.
What is a dendrite?
Chemical signaling works fine over microscopic distances, but it fails when an organism grows to this scale.
What is macroscopic?
To send an electrical signal down a meter-long axon, neurons rely on a rapid shift of these charged particles.
What are ions?
Centralization allowed organisms to not just react to the world, but to ________ thoughts and experiences.
What is process?
Thanks to closed-loop feedback, an individual animal can change its behavior in weeks or days through this mental process.
What is learning?
This division of the involuntary nervous system prepares your body for "fight or flight" by speeding up your heart rate.
What is the sympathetic nervous system?
Even in our modern electrical brains, chemicals haven't disappeared; they are still used to cross gaps via these molecules.
What are neurotransmitters?
This long extension of a nerve cell can be up to a meter long, acting like a biological power cable.
What is an axon?
Evolutionary centralization typically moved toward the front of the animal, a trend scientists call by this "C" term.
What is cephalization?
A closed-loop system creates this type of ongoing mechanism, where the output of an action is circled back as an input.
What is a feedback loop?
This "rest and digest" system works opposite to the sympathetic system, slowing the heart and stimulating digestion.
This is the specific structural reason diffusion is incredibly slow over long distances; time increases with the ______ of the distance.
This fatty substance wraps around axons like insulation on a wire to make electrical signals travel even faster.
What is myelin?
This protective bony structure evolved alongside centralization to safeguard the main cluster of the CNS.
What is the skull?
In a closed-loop system, if an animal performs an action and experiences pain, it uses that data to do this to its future behavior.
What is modify(or change/stop) it?
While your somatic nervous system is voluntary, this nervous system controls your "autopilot" functions like breathing.