Unit 3: Human Body Systems Review

Muscles that help the skeleton move...

Which of the following organs functions as both a respiratory organ and an excretory organ?

The blood vessels carry nutrients (like glucose) and oxygen to the muscle cells that need them. Blood vessels take away CO2 and waste from muscle cells.

The brain checks the amount of CO2 in the blood and adjusts the rate of breathing. The brain "communicates" with the lungs using nerves from the brain to the lungs.

The brain tells the stomach, intestines, and liver when to be active and when to rest. Messages to and from the brain decide when it's time to process food.

Blood vessels deliver nutrients and oxygen for all the intestinal cells to function. Blood vessels then pick up the nutrients absorbed by the intestines and carry them away to other parts of the body that need them.

Muscles in the intestines continually contract and break down food into nutrients the body can absorb.

Red blood cells go to the lungs to remove CO2 and pick up O2 that has been inhaled. The heart pumps red blood cells carrying O2 from the lungs to all cells in the body.

A friend throws you a ball. Your brain tells your hands to move to catch the ball.

When you're running, you breathe harder and your heart rate increases (pumping more blood) to get more oxygen to your cells to create energy.