Our bodies, when you think about it, have to deal with very different sets of challenges at different times: fending off tigers (or opposing players on the hockey team) is a very different activity than recuperating after a tiger-attack
Our bodies, when you think about it, have to deal with very different sets of challenges at different times: fending off tigers (or opposing players on the hockey team) is a very different activity than recuperating after a tiger-attack or hockey-blow. So throughout the day (or hour, or minute), our bodies move on a spectrum between two key states: “rest and digest” and “fight or flight”
In the “rest and digest” state, our bodies are being kept well-fed and grounded. The walls of the esophagus, stomach, and intestines to keep on churning. Glands that aid in digestion, like the gallbladder, pancreas, and salivary glands become more active.
Since we’re at rest, we don’t really need to work too hard. Our heart muscles start beating slower and less forcefully. We don’t need to breath so hard, so the pathways leading to our lungs constrict.
In the “fight or flight” state, we are on our toes and ready for battle. At a moments notice, we’re ready to pounce - or quickly retreat. When we say a stressful/high pressured activity gives us a “rush of adrenaline” - we’re actually being literal since adrenaline is a family of chemical signals that can stimulate a flight-or-fight response.
We don’t need digestion so all that gets shut off. The digestive system comes to a stop, the glands decrease in activity. Our heart muscles start beating faster and more forcefully. We need a lot of oxygen so those pathways into the lung dilate. We need to make sure that every organ has enough blood and oxygen. To do this, we clamp down on those low-yield arteries of our periphery, keeping most of the blood in the higher-yield central ones. We also open up the arteries leading to important organs (i.e. brain, heart, lungs) and also leading to our skeletal muscles (so that we can actually move with haste).
And in a funny twist of nature, control over sexual function is split between the two systems. Evolution must have thought it both both exciting and restful.
How does our body “make” us go into the right state of being? Basically, the body has two keys systems, and which of them is relatively more active at any given time determines which state we are in. When the Parasympathetic Nervous System (PNS) is relatively more active we will be in the “rest and digest” state; when the Sympathetic Nervous System (SNS) is relatively more active we will be in “fight or f