The parasitic relationship can be defined as the relation in which one organism feeds on the other organism for their nutritional purpose. It can also harm the other organism by any means. Here, tick on the dog is dependent on the dog for its nutritional requirement. This is an example of parasitic relationship between dog and tick.
Parasympathetic will return her heartbeat back to normal. This nervous system is responsible for regulating the body's unconscious actions, and stabilizes it.