Structural imaging aims to reveal brain anatomy, and MRI excels at this because it provides extremely detailed pictures of brain tissue with high spatial resolution. MRI uses strong magnetic fields and radio waves to differentiate between different soft tissues, giving clear, crisp images of structures like gray and white matter without exposing the brain to ionizing radiation. CT also shows anatomy and is quick, but it has lower soft-tissue contrast and uses X-rays. Functional imaging, such as fMRI, is about detecting activity by measuring blood flow changes, not the static structure, while EEG records electrical activity with limited detail about where in the brain things are occurring. So for showing the brain’s anatomy, MRI is the best choice.

Pheromone signaling uses the vomeronasal system, where the vomeronasal organ detects pheromones and sends the signals to the accessory olfactory bulb. This is the first relay in that pathway, making it the direct brain region linked to pheromone processing. From there, information moves to areas like the amygdala and hypothalamus, which helps drive instinctive social and reproductive behaviors. The primary olfactory cortex handles general odors from the main olfactory system, not pheromones; the hippocampus is more about memory; the amygdala is involved downstream in emotion and behavior but is not the initial relay.

Endocrine signaling uses chemical messengers that travel through the bloodstream to reach distant tissues. These messengers are hormones produced by endocrine glands such as the pituitary, thyroid, adrenal glands, and pancreas. Once in the blood, hormones bind to receptors on target cells to regulate processes like metabolism, growth, and reproduction. This system differs from neurotransmitters, which are released at synapses to produce rapid, local effects on nearby neurons or muscles, and from pheromones, which are chemicals released into the environment to influence other individuals rather than the body's own tissues. Because hormones travel via the bloodstream, their effects are typically slower to start but longer-lasting.

Emotion and memory are tightly connected through the limbic system. The amygdala evaluates how emotionally significant a moment is and communicates with the hippocampus to boost memory encoding when arousal is high. This means emotionally charged events tend to be remembered more vividly because the amygdala enhances the consolidation processes in memory formation. The hypothalamus then translates that emotional state into physiological arousal and autonomic responses, so the body prepares for action while the memory is being formed. The hippocampus supports forming and organizing the memory itself, giving it context and detail. In short, the limbic system links what we feel with how we remember and responds to that emotion with bodily changes. Functions like coordinating movement, balancing, or processing vision involve other brain areas such as the cerebellum or occipital lobe.