- alveoli: Tiny air sacs in the lungs where gas exchange (oxygen and carbon dioxide) occurs between the air and the blood; surrounded by capillaries.
- bronchiole: Small, thin-walled airways branching from the bronchi that lead to the alveoli; lack cartilage and are involved in air distribution.
- bronchus (pl. bronchi): Large airway tubes that branch from the trachea into each lung; lined with cilia and mucus-secreting cells to trap debris.
- diaphragm: Dome-shaped muscle below the lungs that contracts and flattens during inhalation to increase thoracic volume, enabling air intake.
- epiglottis: Flap of cartilage at the base of the tongue that covers the trachea during swallowing to prevent food and liquid from entering the lungs.
- glottis: Opening between the vocal cords in the larynx; controls airflow and is essential for voice production.
- larynx: Voice box located in the throat; contains the vocal cords and acts as a passageway for air; also protects the trachea during swallowing.
- lung: Paired organs in the chest responsible for gas exchange; contain bronchi, bronchioles, and alveoli; expand and contract with breathing.
- nasal passages: Air channels within the nose lined with mucous membranes and cilia; warm, moisten, and filter incoming air.
- nostril: External openings of the nasal cavity; serve as entry points for air into the respiratory system.
Parent Tip: Review the logic above to help your child master the concept of the human respiratory system worksheet answers.
