B&B Thermoreception Flashcards
Why is sensing of temperature important?
Helps us react to noxiously cold and hot objects
Helps us maintain constant body temperature
What is thermoregulation?
The maintenance of body temperature
What is homeostasis?
Active maintenance of a relatively constant internal environment
How do we warm our bodies?
Through metabolic activity
Shivering
Cutaneous vasoconstriction
Seeking warmth
How do we cool our bodies?
Evaporative mechanisms
Panting,sweating
Cutaneous vasodilation
Seeking cool,shady places
What is heterothermy?
Animals that vary between self-regulating their body temperature, and allowing the surrounding environment to affect it
What is a homeotherm and a poikilotherm?
H =Maintains a constant internal body temperature, usually within a narrow range of temperatures
P = An animal that varies its internal body temperature within a wide range of temperatures, usually as a result of variation in the environmental temperature
What are some factors that contribute to heat death?
Denaturation of proteins
Thermal inactivation of enzymes exceeding rates of formation
Oxygen limitation
Effects on membrane structure
Different processes in metabolic networks have different temperature dependence
What is the Q10?
Temperature increases accelerate many processes
This increase in rate caused by a 10c increase is the Q10
Q10 = (R2/R1)^10/(T2-T1) where R2 and R1 are rate values of a process measured at temperatures T1 and T2
What are typical Q10 values for biological processes?
Between 2 and 3
There is an exponential relationship between rate and temperature
Are the following processes thermosensitive?
Q10 < 4
Q10 > 7
Not particularly
Yes
What is a fever?
Increase in body temperature usually associated with an infection
What is 0 K in C
-273.15
How many joules is 1 cal?
4.184
Heat is measured in calories where 1 calorie is the energy required to raise the temperature of one gram of water by one degree Celsius.
What is the specific heat capacity?
The amount of heat required to raise the temperature of 1 kilogram of a substance by 1 kelvin
1.0 cal g-1 c-1. It is 0.8 for the mammalian body
J kg−1 K−1