Psychology = Aries is the virtue& principle of initiating and creating new of seeing things that you are passionate about (Mars). This energy makes you want to burn(Fire element) through physical reality especially things put that structure and boundaries around (Saturn Fall) This passion and desire can turn to anger and aggression if their intent(Mars) is not met. Therefore, now you know your spirit is using the Masculine side of Mars(Root Chakra) whenever you start you having visions or ideas and want to express(Cardinal) them this why people with the alto of aries energy experience headaches & migraine because they overusing an organ that corresponds to Virtue & Principal. Also, Since mars rule the night/Feminine time of Mars “Scorpio” you have a strong neurons connection to your reproductive system that's why it's easy to get aroused by sexual idea or imagination
Physiology = The brain is like a computer that controls the body’s functions, and the nervous system is like a network that relays messages for movement and basic body functions.
The autonomic nervous system has two parts:
the sympathetic nervous system prepares the body for sudden stress, like if you witness a robbery. When something frightening happens, the sympathetic nervous system makes the heart beat faster so that it sends blood quickly to the different body parts that might need it.
the parasympathetic nervous system does the exact opposite: It prepares the body for rest. It also helps the digestive tract move along so our bodies can efficiently take in nutrients from the food we eat.
The planet that the sign is on will show us the quality of that organ/nervous system.