Monday, December 9, 2019

Human Dive Response free essay sample

To characterize the dive response, we measured subjects’ heart rates at rest and with their face submerged under a tub full of room temperature water. After that initial step of the experiment, two more treatments were tested to see whether or not it would affect the dive response; when resting, the subject would be able to breath during the thirty seconds, and when submerged, the subject could move their feet slowly as if they were swimming. The latter treatment experiments were then compared to the first experiment done, where the result was used as a control to the new experiments. The purpose of the experiment was to see if there was a difference between the control and experiment; the experiment being movement and breathing. We found that there was a significant difference between the resting and submerged treatments when there is no movement and breathing; (0. 009lt;0. 05; Plt;0. 05). With the breathing experiment; (P=0. We will write a custom essay sample on Human Dive Response or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page 18, Plt;0. 05), there is no significant difference between the control and the experiment, and with the movement experiment; (P=0. 08; Plt;0. 05); this experiment also showed that there is no significant difference in heart rate when moving ones feet and not moving. We were concluded that movement and breathing does not decrease the heart rate for the dive response, but not moving and not breathing during the resting and submerged treatments does change the heart rate for the dive response. Introduction The human dive response was characterized by breath holding, slowing of the heart rate (diving bradycardia). A number of experiments have been conducted over the years, and have shown that the elements of the dive response and breath holding have reduced heart rate. Scientists have been researching topics related to the dive response in both vertebrates that are know for their diving, like seals, and also species that do not have very much diving abilities like humans. Pasche and Krog (1979) conducted an experiment to see the heart rate of resting seals on land and water without the use of restraints on the seals, in order to compare the observed bradycardia in the animals during apneic periods of the two different environmental conditions. Apneic periods are temporary cessation of breathing. Earlier experiments have use restraints on mammals to determine whether or not heart rate decreased or increased when submerged under water. Pasche and Krog found that even though their results showed a more noticeably slower heart rate when the seals dived compared to when on land, there was not a significant difference on a 5% level. As mentioned before, experiments in the past have used restraints on the animals. Animals were restrained and forcibly submerged under water or subjected to forced breathing conditions. Butler and Woakes (1975) have shown that there is a significant difference in the bradycardia during those forced testing’s compared to the natural unrestrained dives. Butler and Woakes used ducks in their experiment. With knowledge of how other experiments were conducted in the past, it gave us a basic understanding of what we could do to make our own experiment. In the first part of the experiment, we wanted to characterize the human dive response in terms of the change of heart rate when submerged and not submerged. We predicted that the heart rate would decrease over a time period of 30 seconds when submerged in water while holding their breath. When in the resting position, each subject held their breath as if they were submerged under the water. They had the same body posture but the only difference was not actually being submerged. The first part of this experiment was used as a control for the second and third experiment done. The second and third experiments had different treatments and were compared to the first experiment. The purpose of our latter portion of the experiment was to t-test the prediction that movement when submerged and breathing while on land can cause the heart rate to decrease in the dive response. Material and Methods Each student got a white tub and filled it up with tap water from the sink. Students were paired with two or three other people and formed their groups. Each group got 1 stopwatch, 1 thermometer, and also learned how to each other’s pulse. The temperature of the water used from the sink were adjusted beforehand to about 23Â °C; room temperature. Water temperature was not re-adjusted to be hotter or colder. All tests were conducted in the same posture; leaning over the lab table with elbows resting on the table and the head down. Students worked in groups of three to four, and each one took turn being the experimental subject, taking the pulse and handling the stopwatch. To measure the radial pulse manually, the subject’s palm was facing upward. The index and middle fingers were used to locate the pulse between the radial bone, which is on the same side as the thumb, and with a slight pressure, the pulse could be found. Each test lasted 30 seconds. Before this experiment began, the students agreed to toss a coin to see which treatment to start off with, to randomize the experiment. One side of the coin was to start the experiment off in a resting posture while holding ones breath and the other side of the coin was to be submerged under water while holding ones breath. During the 30 seconds of the experiment, the first 15 seconds were used to allow the heart rate to adjust and slow down while in the resting and submerged treatments. After all the data was collected, we got the means of the averages and used a data analysis, paired t-test to test whether or not our experiment showed a significant difference, which then would support or reject our hypothesis. Results From the experiment used to distinguish the dive response, the mean heart rates with the subject in a resting position while holding their breath was 63. 89 BPM, and the average heart rate while submerged under water holding breath was 57. 11 BPM (Plt;0. 05) (Table 1). We have concluded that there is indeed a significant difference in the heart rates found in this experiment. In the breathing experiment, the average heart rate mean of not holding ones breath was 61. 25 BPM and the mean heart rate of holding ones breath was 74. 25 BPM (Plt;0. 05, p=0. 18) (Table 2). We can conclude that there is not a significant difference between the two treatments. In the movement experiment, the average mean heart rate of shuffling feet while submerged under water was 69. 2 BPM and the mean average heart rate of the control; not moving feet while submerged under water, was 60 BPM (Plt;0.. 05, p=0. 08) (Table 3). We can conclude from the paired t-test that there is no significant difference between the two different submerged treatments in this experiment. Figure 1. The bars show the means of the heart rate during the resting and submerged treatments are shown. Error bars show the standard error. Table 1. Results of the paired t-test between the two sample for me ans.

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