GENERAL HISTOLOGY

Detailed explanation-1: -Smooth muscle tissue in both bronchioles and arterioles controls those structures’ diameters. Just as vasodilation and vasoconstriction of the arterioles regulate blood flow and distribution, bronchodilation and broncholconstriction control the amount of resistance to air flow and the distribution of air in the lungs.

Detailed explanation-2: -Albuterol is an inhaled short-acting beta-2 agonist that stimulates beta-2 receptors on the surface of airway smooth muscle. The increased sympathetic tone causes the relaxation of airway smooth muscle, which causes dilation of the bronchi and bronchioles, reducing airway resistance.

Detailed explanation-3: -Larger airway diameter results in greater turbulence for the same relative flow velocity (e.g., between a particle and air) . Therefore, flow may be turbulent in the large airways of humans, whereas for an identical flow velocity, it would be laminar in the smaller experimental animal .

Detailed explanation-4: -Nervous System Control The autonomic nervous system usually determines airway diameter. Sympathetic innervation causes relaxation of bronchial smooth muscle via beta-2 receptors, which causes an increase in airway diameter to allow more airflow.