What happens when you pass out

https://www.healthline.com/symptom/fainting#modal-close
https://www.webmd.com/brain/understanding-fainting-basics#1
https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/fainting
https://theconversation.com/fight-flight-or-faint-why-some-people-pass-out-when-they-see-blood-or-feel-pain-57348
https://www.medicinenet.com/fainting/article.htm#introduction_to_fainting_syncope
https://medium.com/desk-of-van-schneider/if-you-want-it-you-might-get-it-the-reticular-activating-system-explained-761b6ac14e53
http://www.health.com/mind-body/5-things-that-can-make-you-faint
https://www.sciencedirect.com/science/article/pii/S1566070214000630
https://www.nhs.uk/conditions/fainting/causes/