BPK 142 Lecture Notes - Lecture 9: External Intercostal Muscles, Alveolar Pressure, Thoracic Cavity

• School: Simon Fraser University
• Department: Biomedical Physio & Kines
• Course: BPK 142
• Professor: Craig Asmundson

Document Summary

Pulmonary structure and function: anatomy of the respiratory system. Respiratory system consists of nose, pharynx, larynx, trachea, bronchi, and lungs. Bronchi - primary, secondary, and tertiary bronchi ---> terminal and respiratory bronchioles ---> alveolar ducts ---> alveoli. With branching, supportive cartilage is gradually replaced by smooth muscle. Contraction and relaxation of this smooth muscle constricts or dilates the bronchioles --> major effects on airway resistance. The conducting airways lead inspired air to the alveoli. Volume of conducting airways = anatomic dead space (vd) - 150 ml. Alveoli - small, thin walled sacs that have capillary beds in their walls; site of gas molecule (o2 & co2) exchange between air and blood; there are millions of alveoli. Respiratory membrane alveolar-capillary membranes that separate the air molecules in the alveoli from the blood in the capillaries - average thickness is 0. 6 micrometers.