When our bodies demand high blood input, our veins expand, since more blood flows through them to nurture our muscles. This, in turn demands more heat rate. The brain detects this increase in heart rate and it sends chemical messages to turn it down. So the correct option is C. the heart beat. The other options does not have a role with blood pleasure regulation, although they might influence its performance.
Animal cells don't have mitochondria and have smaller vacuoles than plant cells <span />
Jupiter. The largest planet in our solar system by far is Jupiter which beats out all the other planets in both mass and volume. Jupiter's mass is more than 300 times that of Earth and its diameter at 140,000 km is about 11 times Earth's diameter
I believe the correct answer is d.
