3 Fill in the blanks: The is the lungs\' outer membrane, which adheres to the inner wall of the thoracic cavity. At the lungs\' root, in itself to become the inner membrane called the it folds on which adheres to the lungs\' surface. Between the two layers of membrane is the 4 How do the respiratory zone and the conducting zone differ? 5 Number the following structures of the respiratory tract in the proper order The structure that comes into contact with oxygenated air first should be number 1, and the structures where gas exchange takes place should be number 11. oropharynx Trachea Nasal cavity Bronchiole Alveolar sac Nasopharynx Bronchi Terminal bronchiole Laryngopharynx Respiratory bronchiole 6 The piece of elastic cartilage that seals off the larynx during swallowing is called the a. uvula. b. false vocal cord. c. true vocal cord. d. epiglottis 7 Passages in the respiratory tract s than 1 mm in diameter are called a. bronchi. b. bronchioles. c. alveolar ducts. d. paranasal sinuses. Solution (1) Outer Pleural membrane and inner plural membrane and plural fluid is filled in between the two membrane its help in the protection of lungs from external injuries..