Just doesn’t make sense
Our temperature is higher
We should feel hot (IMO) 🤷♂️
Edit 1: With that why do we feel so weak and tired when sick/have a fever
In: 3288
There are multiple different mechanisms at play here, because… the body is COMPLEX! lol. I’m gunna break it down physiologically
1) – An infection is caused by a pathogen (bacteria, virus, fungi, etc..) This pathogen is recognized by the immune system as foreign. Immune cells then are triggered, which causes a release of chemicals from those cells that will cause a physiological response (these chemicals can be cytokines, Interleukins, Interferons, etc..).
2) Some of these chemicals (specifically Interleukin- 1, Interleukin – 6, Interleukin -8, Interferon- Gamma) flow through your body and reach your brain.
3) Your body temperature is regulated by a “thermostat” in the brain ( specifically the hypothalamus, of which temperature regulation is just one of the functions). The chemicals released into the body due to infection will go to the hypothalamus and tell it to “raise the temp, we got bugs causing some shit somewhere. Cook em up”. This causes a rise in body temperature from its normal resting temp to a higher one, which we call a fever.
4) Along with this, we have a function of the human body to regulate how our blood vessels work. Blood vessels can constrict and can expand depending on how much blood is needed in a particular organ. Blood carries white blood cells, red blood cells, basically everything you need to live and fight off disease, and it is *warm (*and blood cools itself when it flows through the skin to allow heat to dissipate). In certain conditions, such as eating, blood vessels supplying the skin will constrict in order to ensure more blood is sent to the gut to provide energy for digestion of food. In an infection, blood vessels keep more blood around the “vital” organs (heart, brain, lungs, etc) because these organs are a necessity for the body to function. This further increases core body temperature.
5) So now you have blood concentrated in the core organs internally and chemicals causing your thermostat to raise the temperature. The difference between the temperature between the internal organs and outermost organs (skin) is greater. This difference is what causes the feeling of “cold” as sensory receptors on and around the skin and other outer organs send signals to the brain via a spinal cord nerve tract called the “spinothalamic tract” that the difference between the environment and internal temperatures is greater. Think about when you go from inside your house in winter versus in summer. In winter, the outside temperature is lower than your internal temperature, thus you feel “cold”. Where as in summer, the outside temperature can be greater than the inner temperature, so you feel hot.
This difference is what is the cause of shivering. Shivering is one of the body’s mechanisms to raise it’s temperature via muscle activity. As muscles work they use energy from glycogen and other substances derived from the food we eat. This energy usage is not 100% efficient, and the un-used energy is given off as heat (Newton’s law of thermodynamics). This is the body’s way of attempting to heat the outer organs, as the skeletal musculature is closely attached to the skin via the subcutaneous tissue and fascia and shivering lets heat to flow out to the outer portion. Think about it. When was the last time you felt cold and then felt your liver or spleen or pancreas shaking inside you trying to stay warm? they don’t.
6) Weakness and tiredness are also related to these mechanisms. When those chemicals (cytokines, Interleukins, interferons) are released, some of them cause weakness and tiredness as well. This has a very good purpose: when fighting an infection, the body wants you to use all your resources to overcome this infection as fast as possible. Weakness is there to ensure you do not do something dumb, like a boxing match or run a marathon, while fighting the infection. Body doesnt want to share resources for unnecessary activities. Tiredness is to promote sleep. During sleep, your body releases more chemicals (complement system, etc) to fight infection. basically your immune system is MORE active while you are asleep than when you’re awake. Basically the body wants you to be in bed and asleep so it doesn’t have to divert energy towards frivolous junk activities while it is busy slaughtering foreign pathogens.
Latest Answers