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.
