1. Table of Contents The Respiratory System Smoking and Your Health
The Excretory System

2. The Air You Breathe - The Respiratory System
The air you breathe in contains several different gases, shown in the circle graph on the left. The air you breathe out contains the same gases, but in the amounts shown in the circle graph on the right.

3. The Air You Breathe - The Respiratory System Reading Graphs:
What does each wedge of the graphs represent?
Percent of a gas breathed in or out

4. The Air You Breathe - The Respiratory System Interpreting Data:
Based on the data, which gas is used by the body? Explain.
Oxygen; less oxygen is breathed out than breathed in—meaning that some must have been used by the body.

5. The Air You Breathe - The Respiratory System Drawing Conclusions:
Compare the percentage of carbon dioxide in inhaled air with the percentage in exhaled air. How can you account for the difference?
There is a higher percentage of carbon dioxide in exhaled air. Carbon dioxide is a waste product of cellular activity.

6. The Air You Breathe - The Respiratory System Inferring:
Explain why the percentage of nitrogen is the same in both inhaled air and exhaled air.
Nitrogen is not used by the body and is not a waste product.

7. Respiratory System Functions
- The Respiratory System
Respiratory System Functions
Oxygen from the air and glucose from digested food are both carried to the cells by the blood. During respiration, oxygen reacts with glucose to release energy.

8. The Path of Air - The Respiratory System
As air travels from the outside environment to the lungs, it passes through the following structures: nose, pharynx, trachea, and bronchi.

9. Gas Exchange - The Respiratory System
After air enters an alveolus, oxygen passes through the wall of the alveolus and then through the capillary wall into the blood. Carbon dioxide and water pass from the blood into the alveoli.

10. Surface Area - The Respiratory System
Surface area refers to the total area of all the surfaces of a three-dimensional object. Consider a cube, which has six equal sides. Each side measures 2 cm by 2 cm.
1. To find the surface area of the cube, first calculate the area of one of the six sides:
Area = length X width = 2 cm X 2 cm = 4 cm2
Each side has an area of 4 cm2.
2. Then, add the areas of the six sides together:
4 cm2 + 4 cm2 + 4 cm2 + 4 cm2 + 4 cm2 + 4 cm2 =
24 cm2
The surface area of the cube is 24 cm2.

11. Surface Area - The Respiratory System Practice Problem
Calculate the surface area of a cube whose side measures 3 cm.
54 cm2

12. How You Breathe - The Respiratory System
When you breathe, the actions of your rib muscles and diaphragm expand or contract your chest. As a result, air flows in or out.

13. Breathing Process Activity
- The Respiratory System
Breathing Process Activity
Click the Active Art button to open a browser window and access Active Art about the breathing process.

14. Breathing and Speaking
- The Respiratory System
Breathing and Speaking
Two vocal cords, folds of connective tissue that produce your voice, stretch across the opening of the larynx. Air moving over the vocal cords causes them to vibrate and produce sound.

15. Sequencing - The Respiratory System
As you read, make a flowchart that shows the path of air in the respiratory system. Write each step of the process in a separate box in the order in which it occurs.
Path of Air
Air enters the nose.
To the pharynx
To the trachea
To the bronchi
To the lungs
To the alveoli

16. End of Section: The Respiratory System

17. Chemicals in Tobacco Smoke
- Smoking and Your Health
Chemicals in Tobacco Smoke
Some of the most deadly chemicals in tobacco smoke are tar, carbon monoxide, and nicotine.

18. Health Problems and Smoking
- Smoking and Your Health
Health Problems and Smoking
Over time, smokers can develop chronic bronchitis, emphysema, lung cancer, and atherosclerosis.

19. Relating Cause and Effect
- Smoking and Your Health
Relating Cause and Effect
As you read, identify the effects of smoking on the body. Write the information in a graphic organizer like the one below.
Effects
Increase in breathing and heart rate due to carbon monoxide in smoke
Cause
Damage to protective cilia and risk of cancer due to tar
Smoking
Addiction and increase in blood pressure due to nicotine
Risk over time of chronic bronchitis, emphysema, lung cancer, and atherosclerosis

20. Links on Respiratory Disorders
- Smoking and Your Health
Links on Respiratory Disorders
Click the SciLinks button for links on respiratory disorders.

21. End of Section: Smoking and Your Health

22. Filtration of Wastes - The Excretory System
Each kidney contains about a million tiny filtering units called nephrons.

23. Previewing Visuals - The Excretory System
Before you read, preview Figure 11. Then write three questions you have about the diagram in a graphic organizer like the one below. As you read, answer your questions.
How the Kidneys Filter Wastes
Q. Where are nephrons located?
A. In the kidneys
Q. What three main materials are filtered out of the blood?
A. Urea, water, glucose
Q. What happens to these filtered materials?
A. Most of the water and glucose are reabsorbed. Most of the urea remains as urine.

24. Links on Organs of Excretion
- The Excretory System
Links on Organs of Excretion
Click the SciLinks button for links on organs of excretion.

25. Click the Video button to watch a movie about sweat.
- The Excretory System
Sweat
Click the Video button to watch a movie about sweat.

26. End of Section: The Excretory System

27. Graphic Organizer Blood flows into the nephron’s capillary cluster.
Water, urea, glucose, and other materials are removed from the blood and flow into the capsule.
From the capsule, the substances flow into a long tube.
In the tube, glucose, water, and some other materials are reabsorbed.
Urine flows from the kidneys through the ureters to the urinary bladder.

28. End of Section: Graphic Organizer