1) which choice lists the structures adapted for permitting air flow from the external environment to the human lungs in the correct order? a) nasal cavity, bronchi, bronchioles, pharynx, trachea b) nasal cavity, trachea, pharynx, bronchi, bronchioles c) nasal cavity, pharynx, trachea, bronchi, bronchioles d) nasal cavity, bronchioles, trachea, pharynx, bronchi 2) a structural difference between the trachea and esophagus that prevents the trachea from collapsing is the presence of: a) smooth muscle b) skeletal muscle c) respiratory cilia d) rings of cartilage 3) in order for gas exchange to take place, alveoli must be closely associated with: a) capillaries b) villi c) veins d) arteries 4) deposits from cigarette smoke interfere with the normal functioning of cilia in the: a) trachea b) esophagus c) bronchioles d) pharynx 5) the exchange of air between the human body and the environment is the result of coordinated contractions of the muscles of the rib cage and the: a) lung b) diaphragm c) heart d) pleura 6) the site of gas exchange in humans is the: a) nasal cavity b) trachea c) pleura d) alveoli 7) a disease involving the breakdown of the air sacs in the lungs is: a) asthma b) emphysema c) pneumonia d) bronchit 12) which structure warms & filters air as it is inhaled?