Tag: respiratory system

Respiratory System, Part 1: Crash Course A&P #31

September 15, 2019 Nicole Stewart

Pretend for a minute that you can’t breathe. Like, you just don’t have lungs anymore. You are some bizarre evolutionary oddity — a huge, human-shaped organism that doesn’t have a respiratory system. Instead, you get all of your oxygen the way that your oldest, smallest evolutionary ancestors did — by simple diffusion.