Question

does anaerobic conditions also present in human body
please explain in which part

Answer 1

anaerobic take place in muscles during vigorous exercise

Answer 2

Carbon dioxide is a byproduct of aerobic respiration in humans. Yes. When humans and other animals lack sufficient oxygen, they'll create ATP through a form of anaerobic respiration that produces lactic acid as a byproduct. Lactic acid fermentation is a form of anaerobic respiration.