First, I see no italics. Second, your sentence looks like it has no errors.
Well the hormone would be one thing. I'd say because it strengthens our heart muscles and trains our breathing pattern to be more effective. These would lead to more efficient transportation of blood and hence oxygen to our whole body including our brain. Our brain becomes more alert, and our body more energetic.
Help her sit down,Call an ambulance, keep her talking dont let her fall asleep, if she falls unconscious check iif she is breathing and if she isnt immediately start CPR <span />