Drowning

Why are our muscles/blood red? -presence of myoglobin in the blood -haemoglobin is myoglobin's cousin -when running very fast, there is not enough time for oxygen to be transported so the body will take oxygen debt from myoglobin -when too much oxygen debt, lactic acid will be produced due to in-aerobic respiration -may cause fainting or spasms -after stopping exercise, you pant to compensate for the oxygen -lactic acid will go to the liver and is deemed as a poisonous substance in the body -will become water and oxygen

Cockroaches don't drown easily because of their respiratory system, they need very little oxygen to survive Their tracheal is fully filled up with water, then the oxygen in the water diffuses into the body Oxygen has to enter our body by dissolving We breathe in air, not oxygen Haemoglobin will bind to the oxygen but nothing will bind to nitrogen(which is present in air as well)

Properties of gas exchange surfaces -large surface area to volume ratio -thin membranes -moisture -ventilation system -concentration gradient from -efficient transport system (circulatory system)