Pressure changes

1. Internal respiration(Inhalation)- Results of cellular respiration; involves the uptake of 02 & production of co2 within individual cells

1.1. The diaphragm contracts and pulls downward while the muscles between the ribs contract and pull upward. This increases the size of the thoracic cavity & decreases the pressure inside. As, a result air rushes in a fills the lungs

2. External respiration(Exhalation)-Includes all processes in exchanging 02 & Co2 with the environment

2.1. Durning expiration, the diaphragm relaxes and the volume of the thoracic cavity decreases while the pressure within it increases. As, a result the lungs contract and air is forced out

2.1.1. 3 process of external respirations

2.1.1.1. Pulmonary ventilation-Breathing

2.1.1.2. Gas diffusion-Across membranes and capillaries

2.1.1.3. Transport of 02 & Co2- Between the alveolar capillaries; between capillary beds in other tissues