However, they are absorbed, usually as methyl mercury, by algae at the start of the food chain. This algae is then eaten by fish and other organisms higher in the food chain. Fish efficiently absorb methyl mercury, but excrete it very slowly. Methyl mercury is not soluble and therefore not excreted.
For example, a 10- to 15-minute brisk walk typically elevates the heart rate to 110 to 120 beats per minute. Also, the sinus node increases the heart rate when the body is stressed because of illness. In all of these circumstances, the heart rate increase is a normal response. Likewise, the sinus node signals the heart to slow down during rest or relaxation.
Exercise increases the rate at which energy is needed from food. This increases the need for both food and oxygen in the body. This is why your pulse rate and breathing rate increase with exercise.Your pulse is just an indication of your heart rate as your arteries expand each timethe ventricles pump blood out of the heart.xercise increases the rate at which energy is needed from food. This increases the need for both food and oxygen in the body. This is why your pulse rate and breathing rate increase with exercise.