Respiration And Lung Volume Lab Report

Introduction

Energy is vital for life. Oxygen is necessary for the production of energy in the form of ATP within cells in the process of oxidative phosphorylation and is sourced from the atmosphere through the process of ventilation. Breathing involves the movement of oxygen in and carbon dioxide out of the lungs in a cyclic pattern which alters in response to the body’s energy requirements or may be altered by health conditions. Respiration and lung function are determined primarily by the organs ability to change their size and volume in response to pressure changes within the thoracic cavity. Lung volume can be affected by many variables as described by Poiseulles law showing the relationship between flow of air and pressure difference,

The intrapleural pressure reduces leading to an increase in transpulmonary pressure drawing the lungs outward to fill the cavity and therefore drawing air into the lungs due to the reduction in alveolar pressure. Expiration at rest is driven by the elastic recoil of alveolar tissue as well as surface tension created by water molecules in the alveoli. Obstructive pulmonary diseases cause an increase the resistance of the airways or reduction of the radius of the tube, reducing the rate at which the lungs can inspire air (FEV1) and also reducing the FEV1/FVC and the PEFR. Emphysema is an example of an obstructive pulmonary disorder where alveolar tissue is damaged resulting in a reduction in alveoli and air spaces in the lung. Restrictive pulmonary disorders result in a decrease in compliance of the lung reducing its volume (FVC and FEV1) but causing no change in PEFR. Restrictive pulmonary diseases include pulmonary fibrosis where scarring of the lungs results in stiffness and reduces the compliance of the

Pulmonary disorders such as pulmonary fibrosis are associated with ageing and so the age of a person is an important parameter to take into account. The height of a person is indicative of their size and lung volume is directly correlated with size of their organ and therefore size of the person. Men are seen to have a larger lung capacity than females which may also be associated with their size. The ethnic background of the subject is also important due to the altered altitude, cultural diet and other factors affecting their lung function. These factors were all taken into account during the