Thermoregulation Flashcards
(14 cards)
Why is homeostasis important
- Metabolic processes require an optimal temperature
- At temperatures higher than 37 degrees, enzymes begin to denature
- At temperatures lower than 37 degrees, chemical reactions in the body start to slow
- Cell function maybe compromised
How much temperature variation is too much
A rise of only 2 degrees will make a human feverish and unwell. Temperatures reaching 43 to 45 can cause death.
Tolerance to lower temperatures is much greater and temperatures need to fall below 23 degrees for it to be fatal.
Daily fluctuations
Lower in morning
Monthly fluctuations
Women hormonal
Behavioral response
Where we consciously change our behavior
Physiological response
Where our body automatically alters it’s functioning without conscious control
Temperature receptors
Peripheral and central
Peripheral receptors
Located in skin and mucous membranes, send message to hypothalamus
Either
1. Cold receptors
2. Heat receptors
Central receptors
Located in hypothalamus (some in spinal cord and abdominal organs)
Methods of heat transfer conduction
- Direct
- Convection
- Radiation
- Evaporation
Direct heat transfer
Contact between particles. Reverse happens when you touch something hotter than your body
e.g. If you touch a cold object heat passes from your body to the object
Convection
An object will heat or cool the air as it passes over the object. the opposite applies to warm air.
e.g. A cold breeze or fan passing over skin will cool down the area
Radiation
The movement of heat from a warmer object to a cooler object across apace (no contact)
Evaporation
This occurs when liquid water is converted into water vapor. As we sweat the evaporation from the skin cools the body.
