How does our body respond when adrenaline is secreted into blood?

Adrenalin hormone is secreted in small amount all the time but in large amount, when a person is frightened. As a result, the heart beats faster to supply more oxygen to our muscles.

The blood supply to the digestive system and skin is reduced and more blood is diverted to our muscles.

The breathing rate also increases. It also allows more glucose to go into the blood to give us a lot of energy quickly to fight or run away from the frightening situation. Therefore, it is often called emergency hormone.

both anaerobic and aerobic respiration use glucose (or other carbohydrates), proteins and lipids to produce atp and nadh. cell uses those energy molecules, obtained from food and   breaks them down during the chemical reactions of respiration. in anaerobic respiration, nadh is regenerated to nad+ by enzymes lactate dehydrogenase (lactate is produced, e.g. in muscle cells) or by alcohol dehydrogenase where ethanol is produced (alcohol fermentation), while in aerobic respiration, electrons from nadh are deposited in the mitochondria to regenerate nad+ (electron transport chain. anaerobic respiration produces 2 atp per molecule of glucose compared to aerobic respiration where about 38 atp molecules are produced.