5.5 Check Your Understanding
CHECK YOUR UNDERSTANDING—SUGGESTED
ANSWERS
1. There are three ways your body gets rid of wastes in the
blood. Blood carries carbon dioxide to the lungs, where it is
exhaled. Sweating gets rid of salts. The urinary system gets
rid of wastes in urine.
2. Your kidneys leave nutrients and most of the water in the
blood. They filter out wastes and some of the water.
3. Your kidneys return more water to the blood if the body
doesn’t have enough water. If there is too much water, your
kidneys remove the extra water in urine.
4. If your kidneys stopped working, the waste materials
would build up in your blood and you would get sick.
5.6 Check Your Understanding
CHECK YOUR UNDERSTANDING—SANSWERS
1. The digestive system releases the nutrients from the food
you eat and passes them to the blood in the circulatory
system through the walls of the small intestine.
2. The respiratory system delivers oxygen to the blood
through the air sacs in the lungs and removes the carbon
dioxide at the same time.
3. The excretory system filters all of the blood in the
circulatory system to remove wastes. It also keeps the right
amount of water in the blood.
Chapter 5: Review Key Ideas and Vocabulary—
Suggested Answers
Pg. 115
1. Blood vessels move blood to and from your body cells. Blood
cells and plasma in the blood pass oxygen and nutrients into a cell
through the cell’s membrane. The cell passes carbon dioxide and
wastes into the blood the same way.
2. Blood from the body returns to the right side of the heart in
veins. It has a lot of carbon dioxide. The right side of the heart
pumps blood to the lungs where it exchanges the carbon dioxide
for oxygen. The blood with oxygen returns to the left side of the
heart. The left side of the heart pumps this blood to the body in
arteries.
Students’ diagrams should be similar to the diagram on page
104 of the student book.
3. All of the blood in the body is filtered through the kidneys.
The kidneys remove the waste and any extra water and send it to
the bladder, where it is released from the body.
4. The blood in the circulatory system transports the oxygen from
the respiratory system and the nutrients from the digestive system
to the cells of the body. Cells burn the oxygen and nutrients to
release energy. This produces waste. One waste is carbon dioxide.
Blood carries carbon dioxide back to the lungs where it is exhaled.
The other wastes in the blood go through the excretory system
where the kidneys filter them out of the blood.
5
Meeting Individual Needs