Respiratory Conducting Zones Respiratory zone Site of gas

Respiratory & Conducting Zones Respiratory zone - Site of gas exchange • Consists of bronchioles, alveolar ducts, and alveoli Conducting zone • Provides rigid conduits for air to reach the sites of gas exchange • Includes all other respiratory structures (e. g. , nose, nasal cavity, pharynx, trachea) • Respiratory muscles – diaphragm and intercostal muscles that promote ventilation

Respiratory Functions I. Provide surface area for the diffusion of gasses A. Oxygen (To be transported to the cells for aerobic respiration) B. Excrete carbon dioxide II. Warm, moisten, and filter inspired air III. Regulate blood p. H

• Respiratory Organs Breathing structures Nose (Filters air) Sinuses (Warm and moisten air) Pharynx Trachea Lungs a. Bronchi b. Bronchioles c. Alveoli

Respiratory Organs Accessory structures Diaphragm Contraction results in inhalation Relaxation results in exhalation Vocal cords

Pulmonary Ventilation • A mechanical process that depends on volume changes in the thoracic cavity • Volume changes lead to pressure changes, which lead to the flow of gases to equalize pressure V P F (flow of gases)

Boyles Law • Boyles law – the relationship between the pressure and volume of gases P 1 V 1 = P 2 V 2 • • • P = pressure of a gas in mm Hg V = volume in cubic millimeters Subscripts 1 and 2 represent the initial and final conditions, respectively

KNOW THESE CHEMICAL REACTIONS!!!! At the alveoli of the lungs At the somatic cells

Healthy Lungs and Smokers Lungs

Pseudostratified Ciliated Columnar Epithelia

3 lobes of a lung on the right and 2 on the left…WHY?