The characteristic that the nurse will describe is HIGHER PITCHED.
When it comes to heart beating in children and adults, one major difference between the two is that, the heart sound typically auscultated in children has higher pitch than that of the adults.
When it triggers an abnormal or vigorous immune responce, treating the antigen that would normally cause no threat as something harmful.
Femur which is the thigh bone is the strongest largest and longest bone of human skeleton