Environmental Stress: Heat
Heat is an environmental stressor that can be detrimental to the human race, possibly even resulting in death. Although adapting to the cold weather is more difficult psychologically then adapting to extreme heat conditions, more people die from heat then they do from intense cold. Hyperthermia occurs when the body temperature of a human rises to 105-107 degrees Fahrenheit. When an individual experiences this type of heat paired with humidity, the body cannot cool itself by releasing sweat, due to the fact the sweat can no longer evaporate because of the humidity surrounding the individual. However, in dry heat, the sweat is evaporated too quickly, resulting in the body losing the needed water and salts from the body. Hyperthermia can result to death in a matter of a few days, or even as less as 24 hours.
Adaptations
1. Short-term: Evaporative cooling is a physiological mechanism in which the body helps prevent itself from overheating. Perspiration is produced from sweat glands and then evaporates from the surface of the skin.
2. Facultative: Vasodilation is the expansion of blood vessels, permitting increased bloodflow to the skin. This is an involuntary response to warm temperatures, which warms the skin and facilitates radiation of warmth, as a means of cooling. Blushing is an example of this.
3. Developmental: One example of this is body size and proportion, to regulate body temperatures. For warm temperatures, the ideal body shape is linear with long legs and arms, because it promotes heat loss.
4. Cultural: The use of clothing one example of a cultural adaptation. The Tuareg who inhabit the nations of Mali, Algeria Niger and Libya, wear loosely fit clothing and head scarfs, which covers most of their bodies. This allows their skin to be safe from the heat radiation, while also giving air flow to the skin to allow necessary sweat to occur.
Although most of us have the ability to adapt to extreme heat sources, we do not know the cultural aspect of this stressor. I believe cultural adaptation is the most important when it comes to heat. It is very important to know the ways of the people who live in these climates on a day to day basis. If we are ever in a climate or environment of this sort, it is not only important for us to be able to use our natural adaptations, but it is also important to know the cultural aspect of it as well in order for survival.
In researching and conducting this blog post, I can now truly understand why it is much more important to study environmental influences on adaptations, rather than the race of the humans whom reside there. Each and every one of us, regardless of skin color or background, all have the ability of evaporative cooling and vasodilation, which are extremely important tools when dealing with extreme heat temperatures. Although we cannot necessarily change our body type, this is something in which is developed due to a need of survival in a certain climate. In this case, it is a tall and slender body type, which can reduce heat. However, this is not developed due to race, it is developed due to environmental influences. In order to develop any of these adaptations, you do no need to be a certain race, it is a matter of adapting to a certain environment in order to survive. Overall I have come to the conclusion that race does not aid in helping us understand human variation.
Good discussion on each adaptation and great images. On correction: Blushing is an example of increased blood flow to the skin surface, but this isn't an adaptation to heat. It is a physiological response to emotional stress of some sort, but the biological process involved is similar in terms of the end result.
ReplyDeleteI think you misunderstood the question in #3, but you ended up addressing this question of the value of the adaptive approach in your response to #4, which was well-argued. Great conclusion as well to the issue of race and very brave of you to say so! The temptation to find some value to race is difficult to overcome.
Well done.
This post is very interesting, I didn't know that those clothes were for keeping cool, I always thought it had to do with sand and UV radiation from the sun. Those head scarves look warming, but like hats, actually seems to cool down at times. I also did heat, so it's good to see another post on the topic.
ReplyDeleteIt's also interesting with your last point that although we may be suited to different climates, we still have the ability to deal with each climate and have a common bond in how our bodies work.
Good Post
I enjoyed reading your blog, however it was my understanding that blushing was a response to emotion to ambient temperatures. I do believe that if you were to be embarrassed in 40 degree temperatures you would still blush.
ReplyDeleteI also found it interesting that you opined that understanding cultural aspects are vital for survival. I think we change culturally as individuals are groups based on what we need not necessarily based on what already exists in the culture we are coming into. Just my humble opinion.
Melissa,
ReplyDeleteGreat discussion on heat adaption! I looked into that one as well and found it to be quite interesting. I thought you brought out some great points and gave great examples for each adaption. I enjoyed your closing paragraph. I too believe that in these times cultural adaption is the most used and most prevalent type of adaption. I like that you mentioned how blushing is a response to your body letting off heat and therefore warming itself. Blushing causes excitement and excitement causes heat. Its a great example of how the body works even on a small daily basis to keep your body regulated. Great job!
I liked that you brought up the point that it is equally important to make ourselves aware of the cultural adaptations so that we can better adjust to the environment we have found ourselves in. I also found it interesting that vasodiliation not only occurs when one is trying to keep cool, but also when one is trying to stay warm as is the case when you drink an alcoholic beverage. The blood vessels widen to allow better blood flow which can be hard to do during times of great cold when that is hard to do. The blood rushes to the surface providing temporary warmth. I too brought up the point that these bodily functions that try to keep us at a state of homeostasis are intrinsically in all of us and race doesn't define our ability to adapt as human beings. Looking at these issues across environmental clines allows us to see how people of different geographic locations adapt to their environments but deep down, all of our bodies are equally equipped to handle foreign situations because our main goal is to survive. Good job
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