Chapter 14

Choose the correct statement. a. During quiet breathing, expiration does not usually involve the contraction of muscles. b. Expiration occurs when the diaphragm and the rib muscles contract. c. Expiration occurs as the chest (thoracic) cavity enlarges. d. The larynx acts like a suction pump to pull air into the lungs.

You should be able to hold your breath longer than normal after you hyperventilate (breathe rapidly for a while) because hyperventilating a. decreases blood oxygen levels. b. decreases blood carbon dioxide levels. c. increases blood oxygen levels. d. increases blood carbon dioxide levels.

Which structure is specialized to produce the sound of your voice? a. trachea b. larynx c. bronchiole d. epiglottis

As a molecule of oxygen enters the body and is delivered to the cells, it passes through many structures. Which sequence shows the correct pathway? a. nose, pharynx, larynx, alveolus, bronchus, trachea b. pharynx, bronchiole, larynx, alveolus, bronchus, trachea c. larynx, pharynx, alveolus, trachea, bronchus d. nose, pharynx, trachea, bronchus, bronchiole, alveolus

What is the most important cue that prompts you to breathe again after holding your breath? a. the decrease in carbon dioxide levels b. the increase in carbon dioxide levels c. the increase in oxygen levels d. the decrease in oxygen levels

What is the reason why we must breathe oxygen? a. Oxygen is broken down to yield energy. b. Oxygen allows us to get more energy (in the form of ATP) out of the food molecules we break down for energy. c. Oxygen stimulates enzyme activity. d. Oxygen is the chemical detected by chemoreceptors that keeps us breathing.

Choose the correct statement: a. Cartilage rings keep the alveoli open. b. The temperature and humidity of the air are adjusted as the air flows through the nasal cavities. c. The larynx changes shape as we speak, creating resonance chambers of different sizes. d. The center of each lung contains a large hollow area in which most of the gas exchange occurs.

Choose the incorrect statement about the production of sound called the voice: a. Speaking sounds are produced when the epiglottis vibrates. b. Thicker vocal cords produce deeper voice sounds. c. Laryngitis results when the vocal cords become swollen and thick and cannot vibrate easily d. There are only two true vocal cords.

When you swallow food, why does it not usually enter the respiratory system? a. The Heimlich maneuver prevents it from doing so. b. The bronchioles produce mucus. c. The diaphragm contracts. d. The epiglottis covers the opening to the respiratory system. e. The vocal cords block the opening to the respiratory system.

In a healthy person, most of the particles that are inhaled into the respiratory system. a. are trapped in the mucus and moved by cilia to the pharynx (toward the digestive system). b. pass through the alveoli into the circulatory system, where they are engulfed by white blood cells. c. are caught on the vocal cords. d. are trapped in the sinuses.

In emphysema, a. the number of alveoli is reduced. b. cartilage rings in the trachea break down. c. the diaphragm is paralyzed. d. the epiglottis becomes less mobile.

The enzyme in red blood cells that reversibly converts carbonic acid to bicarbonate ions and hydrogen ions is ______.