Hormones & Evolution

Describe the electrical stage of neuronal communication

An electrical action potential travels rapidly down the myelin-covered axon when a neuron is stimulated past its threshold.

Describe the chemical stage of neuronal communication

The action potential forces terminal buttons to release chemical neurotransmitters across the microscopic synaptic cleft to bind to post-synaptic receptors.

The difference between Excitatory and Inhibitory neurotransmitters

Excitatory chemicals increase the likelihood that the next neuron will fire an action potential; inhibitory chemicals decrease that probability.

The synaptic mechanism of reuptake

Transporter molecules on the pre-synaptic membrane vacuum up remaining neurotransmitters from the cleft to recycle them into vesicles.

How psychoactive drugs cause biological addiction

They hijack the mesolimbic dopamine pathway by blocking reuptake, flooding synapses with dopamine to create artificial euphoria and reinforcement.

The biological process of Tolerance in drug addiction

Long-term drug abuse causes down-regulation, where the brain removes dopamine receptors, meaning the user needs larger doses to get the same high.

The neurological explanation linking the Amygdala and Prefrontal Cortex to aggression

The amygdala generates rapid survival emotional rage; a damaged prefrontal cortex loses its top-down executive control to inhibit those aggressive surges.

The dual-hormone hypothesis regarding human violence

High levels of testosterone only lead to overt aggressive behavior when baseline levels of the stress hormone cortisol are low.

The evolutionary explanation of human physical aggression

Aggression evolved as an adaptive mechanism to secure scarce food resources, defend land, and establish high social status for reproductive success.

The evolutionary explanation of male sexual jealousy

Evolution triggered male mate retention strategies to prevent cuckoldry, ensuring a man did not waste resource investments on a rival's offspring