1.
Everyone’s body function depends on blood circulation and many chemical
reactions that occur when they body is at a temperature of 98.6 degrees. The
body has natural ways of gaining or losing heat to maintain that normal
temperature. Heat for anybody
can bring illnesses, injuries, and death. When heat stresses the body it
makes the body weaker. Some of the stresses we face when working in a hot
area are temperature, humidity, radiant heat, and wind speed. To ward off
any danger our body must defend itself through breathing, sweating, changing
the blood flow, and constantly staying hydrated. If someone sweats a lot and
does not drink enough fluids, heat exhaustion can happen and if not cared for
can lead to heat stroke. Heat stroke is the most serious heat-related illness. It occurs when the body becomes unable to control its temperature. The body's temperature rises rapidly, the
sweating mechanism fails, and the body
is unable to cool down. Body
temperature can rise to over 100 degrees in a short time frame. When you sweat, more blood
goes toward your body surface for cooling and less is available to serve your
muscles, brain and other internal organs. Prolonged sweating draws a lot of
water from the bloodstream, reducing its capacity to deliver nutrients, clear
out wastes, lubricate joints and cool you later.
2. Short Term- An
example of short-term adaption is sweating. Sweating allows our body to return
to its normal temperature in order to avoid heat stroke. Also, hydrating will
help bring the sweating down.
Facultative- A
facultative adaption example is vasodilatation, which is the dilatation of blood
vessels, which decreases blood pressure. When we are too hot, blood vessels supplying blood to the skin can
swell or dilate. This allows warm blood to flow near the surface of the
skin, which can result to red skin color when people get very hot.
Development- A
developmental adaption example would be weight. Someone who weighs 300 pounds
will sweat much easily than someone who weighs 150 pounds. This is because the more body fat equals more pumping
of your heart, which has to do in order to get blood to all the parts of your
body. The more activity the body has, the higher the temperature, which is why
people sweat much easily.
Cultural-
Cultural adaptation can vary because in some religions or cultures, people are
not allowed to wear tank tops, or short shorts to help with the cooling. But
without short clothing, people can always use a fan.
3. The benefits of studying human variation from this perspective across environmental areas are that it can help us to better understand each other. I have many friends that have a different skin colors for a reason as I can learn from it and understand why. Another benefit can show others and me where we got to, where we are, and where we are headed in the future.
4. Race is not a word that describes a person’s environmental influences. Culture can only define environmental influences, whether it is mine, or others. Culture upbringings allows for variation where race just separates people. Studying the environmental influences can better help us to understand each other, where we come from, and they way we grew up.
Good description of the negative impact on heat stress. Recognize that dehydration is a separate secondary stress. When we talk about heat stress, we are focusing on the impact on the body temperature. Dehydration is the result of of the body trying to adapt to heat stress.
ReplyDeleteGood discussion on your short term and facultative adapations.
The way you describe your developmental trait actually makes it a short term or even a facultative trait. From the information provided in this assignment folder, you should have become familiar with Bergman and Allen's rules, describing how body shape is adaptive to cold or hot climates. Long lean body shapes are adaptive to hot climates (rounder ones to colder). This is related to the issue of heat dissipation (or retention), with long, lean body shapes providing more surface area for releasing excess heat out of the body. Excess weight would not be adaptive in a hot environment. It would trap heat in the body, and the process of sweating is actually costly to the human body in terms of loss of energy and dehydration (as you point out). This is something you would only want to do in the short term.
Good section on cultural adaptations.
More information and knowledge is always a good thing, and I do appreciate your discussion of the social benefits of this approach, but can you think of a more concrete way this information can be used? Can understanding the way heat stress impacts the body have any medical implications, such as in treating heat stroke? Can new clothing that helps deal with heat stress be developed?
I think you are headed in the right direction in your final section, but I'm confused with the reference to culture, since we are really focusing on physiological/biological adaptations here. Back up and think about what race actually is and if it is even possible to use race as an objective basis for understanding human variation. In order to use one factor (i.e., the environment) to explain another (adaptations) you need to have a causal relationship between the two. We see that with the environment, which causes our adaptations to appear. Does race have that causal relationship as well? No, it doesn't. Race doesn't cause adaptations. In a sense, adaptations "cause" race, since they are used as the basis to define race which is just a social construct, subject to bias and interpretation, based upon external phenotypes. Without that causal relationship, race is useless in explaining human variation.
Good images.
Hi Nicole, I got so excited when I saw pictures! I liked the images you chose. Question one, you did a very detailed explanation that I enjoyed reading. I liked that you mentioned a break down of what heat can do to a person when they cannot adapt properly. In your development part of question two, i understand what you meant that heavier people get hot easier forcing them to sweat, but I thought that people would be skinnier in warmer environments and heavier in colder environments since they are trying to retain heat. Other than that, good job!
ReplyDeleteYou did your research for this blog and I had no idea that your blood moves towards your body surface so that it can help you cool down. Its true you learn something new everyday.
ReplyDeleteHey Nicole,
ReplyDeleteGreat Post! I thought your response for a short term adaptation was very precise covering all the points. it is clear you took the time to fully understand the post. I never knew what Vasodilation was until now.