Hot Adaption and Acclimation Tutorial Flashcards
What is one of the main difficulties in evaluating population differences in heat acclimation? How is this rectified?
- The diversity of techniques and reference populations.
- Researchers evaluate thermoregulatory responses to work in heat stress of different populations under the same conditions of temperature and workload
Bantus: Environment?
Summer: 25˚C min 31.1˚C max
Relative humidity: 45-68%
What are the anthropometric characteristics of the Bantus population in comparison to white populations?
- Shorter
- Lighter
- Leaner
- Greater surface area per unit of body
Bantus vs white exercise hot test results
Bantus: 20/20 completed
White: 10/20 completed
Acclimated and non-acclimated Bantus sweated at lower rate + maintained lower rectal temperature + maintained lower heart rate.
Bushmen: Location
Kalahari Desert
Bantus Location:
Central and sub-sahara africa
Bushmen: Location Temperature
Kalahari:
Summer: 18˚C min 32.5 ˚C max
Winter: 3.2˚C min 22.5 ˚C max
Bushmen: Environment
- Annual rainfall
- Highest recorded temp
Annual Rainfall: 400-600mm
Highest temp <60˚C
What is the most important factor for bushmen subsistence:
Distribution of waters sources
What is the predominant food of the Bushmen?
Mongongo nut - hella energy
Bushmen diet:
1/3 mongongo, 1/3 meat, 1/3 veg
Which population do the river Bushmen have similar genetic constitution to and why?
- Bantu population due to proximity and hybridisation.
Difference between Desert and river bushmen
Desert bushmen shorter and lighter. Greater SA/Wt then river bushmen.
Compare the thermoregulatory characteristics of white populations, river and desert bushmen.
River/Desert - Bushmen have similar sweat and rectal temperatures
Desert B = Lower heart rate
Rectal temp and HR of all busmen intermediate of acclimated and non-acclimated white pop.
Bushmen as whole sweat less than whites.
BUSHMEN PARTIALLY ACCLIMATED
Aboriginal: Environment?
Summer 22˚C min 37˚C Max
Winter: 4˚C min 21˚C max
What is the subsistence economy of Indigenous populations?
- Capture of small game and gathering of wild roots and fruit plants.
Are Bushmen or Indigenous Australian’s in a more ‘stressful’ environment in terms of resources, water availability and presence of high temperatures?
Australian Indigenous
Bantus, Bushmen, Aboriginal anthropometric characteristic comparison:
Aboriginal = Tallest of three (Tall as white population), lightest in weight of the three, thus Aboriginal populations have the highest SA/Wt ratio (sans desert bushmen)
Compare the thermoregulatory characteristics of the Indigenous Australians to the Bantus, Bushmen and white populations.
- Rectal temp + HR higher than acclimated whites.
- Sweat rates lower than acclimated whites
- Similar results to Bantus and Bushmen
Chaamba Arabs: Location
Sahara
Sahara vs Kalahari environment:
Saha has higher temperatures and lower humidity.
Chaamba Arabs: Environment
- summer temps,
- annual rainfall
Sahara:
- Summer: 26˚C min 37.5˚C max
- Annual Rainfall: 100mm
Compare the anthropometric characteristics of the Chaamba Arabs to whites:
- CA has higher SA-Wt ratio
- 2.91 vs. 2.60 cm2/kg`
Compare the thermoregulatory characteristics of the Chaamba Arabs (and French whites for this experiment) to the acclimated whites from the African experiments:
- CA and french whites had higher rectal temperatures and higher heart rates.
- In last 2hrs, CA had lower sweat rates than French whites
- CA response to heat stress inferior to whites
Why do Chaamba Arabs have poorer thermoregulatory responses to heat than the white control population:
- Poor physical conditioning
- CA clothing reduces heat stress by trapping stale air between skin and cloth → Insulates skin from ambient temperature and solar radiation.
- Thus protected themselves effectively enough that normal state has seldom exposure to heat stress temperatures/prolonged dehydration.
- Cultural adaption, not physiological
