| A | B |
|---|
| Nose or Nasal cavity | preferred entrance for outside air into the respiratory system. The hairs that line the wall are part of the air-cleaning system |
| Mouth or Oral cavity | another entrance for outside air, especially in people who have a mouth-breathing habit or whose nasal passages may be temporarily obstructed, as by a cold or during heavy exercise. |
| Throat or pharynx | Collects incoming air from the nose and mouth and passes it downward to the windpipe (trachea) |
| Epiglottis | flap of tissue that guards the entrance to the windpipe closing when anything is swallowed that should go into the esophagus and stomach. |
| Larynx | contains the vocal chords. It is the place wher moving air being breathed in and out creates voice sounds. |
| Trachea | Passage leading from the throat or pharynx to the lungs |
| Bronchi | When the trachea divides into two main branches |
| Mucus | Sticky phlegm or liquid which catches and holds much of the dust, germs and other unwanted material that has invaded the lungs. You get rid of this matter when you cough, sneez, clear your throat or swallow. |
| Cilia | These line the bronchi and are like very small hairs and have a wave-like motion |
| Bronchioles | Smalles subdivision of the bronchi located in each lobe of the lungs. |
| Alveoli | Air sacs at the end of the bronchioles only one cell thick |
| Air | 21% Oxygen, 78% Nitrogen and 1% other gases |
| Ribs | Bones that support and protect the chest cavity |
| Capillaries | Blood vessesl that surround the walls of the alveoli. These are only one cell thick and carbon dioxide and oxygen are exchanged here by diffusion. |
| Intercostal muscles | In between the ribs and move to a limited degree, helping the lungs to expand and contract. |
| Pleura | One membrane that is layered twice that surrounds each lobe of the lungs and separate the lungs from the chest wall.The fluid between the two memebrances helps the lungs glide easily against the chest wall during breathing. |
| Diaphragm | The strong wall of muscle that separates the ches cavity from the abdominal cavity. By moving downward, it creates suction in the chest to draw in air and expand the lungs. |
| Inhalation | The process of breathing in. Oxygen is moved into the lungs during inhalation. |
| Exhalation | The process of breathing out. Carbon dioxide is removed during exhalation. |
| Cellular respiration | The process when oxygen has diffused into the bloodstream and the oxygen and nutrients combine to release the energy needed for life activities. The waster products of cellular respiration are carbon dioxide and water. |
