Mechanism of Breathing, BSc, MSc Lecture by Dr. Priyanka Dadupanthi.
Diaphragm and Intercostals muscles are the two important factors of breathing. Intercostals muscles are of two types external and internal. During inspiration diaphram and ext I. M. contracts while int I.M. relaxed. Due to this volume of thoracic cavity increased, pressure decreased and oxygen enters into cavity. During expiration process is just opposite and due to this when volume of cavity decreased, pressure increased carbon dioxide eliminate.