Module 2 week 3 Mechanism of thermoregulation

Goal: 3: The student can explain the mechanism of thermoregulation in humans to professionals, caregivers and older people.

Thermoregulation is a dynamic interaction between an organism’s internal processes and its external environment to maintain a stable physiological temperature. Humans strive to regulate body temperature within a narrow range (∼36.5–37.0°C). This process is a so-called homeostatic process: the human body adjusts itself to conditions with self-regulating processes. Heat puts a great effort into the body to maintain this stable physiological temperature. In the underlying figure, this is explained. If you want to understand more deeply how thermoregulation works you may want to read the following article by Robert D. Meadea et all (2020). https://doi.org/10.1016/j.envint.2020.105909

 

Source: Meadea et all (2020) https://doi.org/10.1016/j.envint.2020.105909

 The regulation of body temperature is overseen by a segment of the brain known as the hypothalamus. It receives feedback on body temperature via the nervous system, triggering compensatory adjustments in breathing rate, blood sugar levels, and metabolic rate. Additionally, the circulatory system plays a crucial role: baroreceptors within blood vessels sense pressure changes and relay this information to the brain, while also transporting hormones from the hypothalamus and thyroid gland to regulate metabolism. Humans dissipate heat through reduced activity, perspiration, and mechanisms facilitating increased blood circulation near the skin surface. Conversely, insulation, reduced circulation to the skin, and cultural practices like wearing clothing or seeking shelter conserve heat. The spectrum between high and low body temperature defines the homeostatic plateau— the "normal" range vital for sustaining life. When either extreme is approached, negative feedback mechanisms kick in to restore the system to its normal range. The regulation of the Human temperature is also nicely described in the video below.

 

 

Deterioration in the regulation of body temperature and maintaining stable blood pressure and organ perfusion are believed to contribute to increased susceptibility to heat as individuals age. The physiological mechanisms that uphold homeostasis during heat exposure are described in the figure below.  It's important to note that the physiological changes associated with ageing and subsequent vulnerability to heat are gradual and closely linked to both genetic factors and lifestyle choices.

Both figures are explained in the following video:

    

   

 Figure: the mechanisms that control the body temperature

Source: Meadea, 2020 https://doi.org/10.1016/j.envint.2020.105909

 



   # References

  • Robert D. Meadea , Ashley P. Akermana , Sean R. Notleya , Ryan McGinnb , Paul Poirierc , Pierre Gosselind , Glen P. Kennya,e, (2020). Physiological factors characterizing heat-vulnerable older adults: A narrative review In Environment International Volume 144, November 2020, 105909 https://doi.org/10.1016/j.envint.2020.105909
  • Eva V. Osilla; Jennifer L. Marsidi; Karlie R. Shumway; Sandeep Sharma. (2023) Physiology, Temperature Regulation. In Statpearls. https://www.ncbi.nlm.nih.gov/books/NBK507838/

 


Última alteração: sexta-feira, 12 de abril de 2024 às 23:32