Nora asked in Science

Help me on this also please

Thank You

Alisha Guglani answered this

Dear student
(a) As breathing rate increases, so does the pulse rate but it is lower than breathing rate. Breathing rate increases to provide the body (exercising muscles) with oxygen at a higher rate. Heart rate increases to deliver the oxygen (and glucose) to the respiring muscles more efficiently.
(b) Muscle contracts when we exercise. Contracting muscle consumes large amounts of oxygen to replenish ATP that is hydrolyzed during contraction; therefore, contracting muscle needs to be able to increase its blood flow and oxygen delivery in order to support its metabolic and contractile activities.