Biology practical 10
January, the 28th, 2013
Respiration is the number of processes which leads to the oxidation of organic compounds to produce the energy. There are several types of respiration, and one of them is aerobic. During the aerobic respiration, human uses the oxygen from atmosphere and produce carbon dioxide. A cardiorespiratory system which includes lungs, heart, blood vessels and others is responsible for all the processes linked to the respiration and controlled by the nervous system. During rest and maximum exercise, nearly all of the ATP needed to maintain the bodily functions is produced by aerobic metabolism. The aerobic metabolism depends on the utilization of oxygen and there is a standard ratio between amount of oxygen consumed and the amount of ATP produced. Since aerobic metabolism takes place in the skeletal muscles, oxygen must be transported from the atmosphere to the muscle cells in order to replenish ATP. Because the rate of oxygen delivery must increase during exercise, the functions of the heart and lungs must also increase during exercise. Respiration exchange ratio should increase when exercises are done because the muscle cells will deliver more CO2 to the bloodstream. Human also must consume more oxygen by inhaling larger amount of air. The objective of the lab practical was to identify a breathing rate of an experimental subject, rate of oxygen consumption and CO2 production alternation regarding the changes of the physical activity level of the subject. In order to find that, also the knowledge of such criteria as a lung capacity, a resting breathing rate and a tidal volume, a blood pressure, a resting pulse rate, inspiratory and expiratory reserve volumes of lungs is needed, so that it is possible to calculate the respiratory exchange ratio. Methods and materials: stethoscope, spirometer, Douglas bag, dry gas meter, CO2/O2 analyzer, stopwatch, breathing mask, peak flow meter, breathing tube, sphygmomanometer, cuff, nose clip, mini-steppers, pulse oximeter, gas syringe. Procedure
a. Measurement of blood pressure and pulse: When the experimental subject is chosen, the sphygmomanometer should be used to measure the blood pressure. The cuff is put on the shoulder up the elbow with some space between arm and a cuff. The inflation valve must be closed. Then, it is necessary to listen to the subject’s pulse using the stethoscope. The cuff should be enlarged until the pressure of 180 mm Hg and then release the air. Note the pressure when the pulse is heard (systolic pressure) and when it is not (diastolic pressure). Stethoscope is needed to count the number of beats per minute too. b. Measurement of respiratory parameters: Switch the spirometer on. Type the information on the subject onto the display of the device. Close the nostrils with nose clip and put the sterilized mouth piece into the subject’s mouth. Before start, the subject should try to breathe through mouth steadily. When finished, push the VC button on the spirometer and the measurement starts. Keep breathing normally until the EVC/IVC appears on the display. Breathe deeply for couple of times and the measurement is over. Take the mouth piece out and push the button to print the results. Get the peak flow meter to obtain the peak expiratory flow rate. To do so, locate the sliding marker to 0, breathe deeply in and blow the air out into the flow meter at the possible maximum force. Note the marker’s showings of the biggest expiratory flow rate of the subject. c. Exercise: This part is done in 3 steps. For all of them the Douglas Bag is required to gather all the subject’s expired air. To know the expired air volume, all the expired air should be put through the dry gas meter, which calculate it automatically. Arrange all the valves between Douglas bag and the dry gas meter in that way so that air from bag could easily pass to the meter. Also, CO2/O2...
Please join StudyMode to read the full document