Lab 6 – The Respiratory System: Spirometry
Akkaraju, Liachovitzky, & McDaniel 2014/15 Experiment by Wolf & Liachovitzky 2014/15
Objectives Checklist - After completion of this lab, you should be able to: describe the mechanics of ventilation: differentiate between static pulmonary changes in volume, pressure and flow tests and dynamic pulmonary function tests identify the muscles involved in ventilation; distinguish those involved in perform pulmonary function tests, and inspiration from those involved in describe the common measurements expiration. made from them (PIF, PEF, FVC and FEV1). distinguish between inspiration & expiration and resting & forced breathing distinguish between restrictive and in terms of energy requirements obstructive lung disorders define the various respiratory volumes describe the effect of airway restrictions and capacities. on PIF, PEF, FVC and FEV1
Pre-Lab Activities A. Ventilation 1. Look at the diagram to the right showing the position of the relaxed diaphragm relative to the ribcage, Demonstrate where the relaxed diaphragm is on your own body. Where will the diaphragm will be when it is contracted? 2. If the diaphragm were to contract, i. what would happen to the volume (space) of your thoracic cavity (increase/decrease)? __________ ii. what would happen to the pressure (increase/decrease)? __________ iii. which way will the air flow (inward/outward)? __________ 3. If the diaphragm were to relax, iv. what would happen to the volume (space) of your thoracic cavity (increase/decrease)? __________ v. what would happen to the pressure (increase/decrease)? __________ vi. which way will the air flow (inward//outward)? __________ 4. Based on your answers to the previous two questions, and the fact that muscle contraction requires ATP, what can you say about the energy requirements of inspiration and expiration (normal quiet breathing using only the diaphragm)? Is inspiration active or passive? What about expiration? • Inspiration: • Expiration: 5. Under conditions where normal breathing isn’t sufficient, other muscles will assist the diaphragm in changing the volume of the thoracic cavity. A muscle that increases the volume of the thoracic cavity will cause pressure to ( / ) which means that it is helping with forced (inspiration/expiration). A muscle that decreases the volume of the thoracic cavity will cause pressure to ( /) which means that it is helping with forced (inspiration/expiration). - 85 -