Money, resources, and the opportunity cost of time spent in the laboratory have led to a reconsideration of the validity of laboratory education. The classic manipulation of diving response in a teaching laboratory revolves around the relationship between heart rate, peripheral circulation and oxygen saturation. The brain, particularly the medulla of the brainstem, maintains the vital functions of the body functioning properly (Abrahams et al., 1991).
Peripheral vasoconstriction is one of the body's main reflexes used to conserve oxygen (Foster and Sheel, 2005). In order to conserve oxygen and preserve what is left for the brain, the exchange of oxygen must be slowed down in other parts of the body (Foster and Sheel, 2005). In an effort to address one of the core competencies established by the National Science Foundation (i.e., demonstrating a relationship between science and society; Wei, 2011), information about human uses for the immersion response was.
In a laboratory setting by manipulating multiple independent variables and measuring dependent variables, students should be able to elicit a greater range of responses compared to typical recreations of the diving response experiment that manipulate only cold water immersion. The first survey was given at the beginning of the experiment and should be completed after participants read. After completing the diving response exercise and the post-laboratory examination, participants received a pizza as a thank you.
The last question of the survey also served as baseline data to measure participants' enthusiasm for completing the lab exercise. These data, along with a semi-laboratory survey, were used to determine the effectiveness of the experiment as a teaching method. Postlaboratory surveys were administered to laboratory participants after completion of the dive response exercise and student analysis (Table 2).
Even with a small sample size, this result supports the successful didactic demonstration of the physiological phenomenon associated with the diving response. Of the 6 groups, only 4 were able to capture the exhaled air in the provided bags. The post-laboratory survey measured the participants' opinion of the knowledge gained and the enjoyment of the diving response exercise.
When asked how their pulse rate responded to breath-holding during cold water immersion, two of the groups reported in their discussion questions that they thought their pulse rate increased. This can be used to show the effect of cold water on the dive response. The students' data show that the main physiological phenomenon of the submersion response was successful, in that heart rate decreased during face immersion in cold water and peripheral oxygen saturation decreased during cold water.
The second competence, using quantitative reasoning, was used by the data analysis part of the laboratory.
Oxygen Saturation and the Dive Response
Student Handout
Oxygen saturation is a measure of the level of oxygen bound to the hemoglobin in the blood, and can be measured via a technique called pulse oximetry. When a person holds their breath, for whatever reason, one of the body's reactions is to conserve the oxygen that is still in the blood and direct it to the brain. Ultimately, less oxygen is used in the peripherals to keep saturation levels higher for brain and heart function.
This means that the oxygen left in the blood when you start holding your breath lasts even longer when the face is submerged in cold water compared to air. In the case of a drowning accident, a person drowning in ice-cold water would have several minutes longer to be rescued and revived before brain damage sets in than in warm water or a person drowning on the ground. By narrowing the blood vessels in the arms and legs, blood flow is diverted away from the limbs and towards the torso and head where more oxygen is needed.
In full-body dives, as would be the case in a drowning event, the response would be even greater with. Contrary to popular belief, the physiological response that forces a new breath is actually a high level of carbon dioxide in the blood, not a low level of oxygen. The systemic basal pressure of carbon dioxide in the body is about 40–46 mmHg, and in the cerebrospinal fluid (CSF) about 25 mmHg.
When carbon dioxide levels rise too high in the CSF surrounding the brain, the pH becomes too low. While chemoreceptors for oxygen levels exist in the aorta and carotid artery, they are not stimulated until the carbon dioxide chemoreceptors have already signaled for a new breath. To analyze the effect of apnea on peripheral circulation and blood oxygen saturation.
To observe the effect of exercise on peripheral circulation and blood oxygen saturation. Squeeze the bag as needed to ensure that the capnometer has access to all of the carbon dioxide in the bag. The equipment operator will then reopen the data collected in the first part of the experiment.
The equipment operator performs an ANOVA analysis of the data collected in the second table. Mean oxygen saturation of hemoglobin in the peripheral systemic circulation of human subjects during apnea under 3 different laboratory conditions and baseline tests.
