Exam 2 (Thermoregulation)

Question 1

What does Q₁₀ measure and what is the equation for it?

Answer 1

How many times faster a reaction occurs when the temperature is increased by 10 C

Q₁₀ = (R₂/R₁)^{(10/T₂ - T₁)}

Question 2

Which type of metabolism is temperature dependent?

Answer 2

Aerobic

Question 3

What is the difference between temperature and heat?

Answer 3

Temperature is the mean KE of molecules in a system; heat is the total KE in a system

Question 4

What is the equation for the rate of heat exchange between two objects?

Answer 4

rate = kA(T₂ - T₁)/d

Question 5

What are the two types of convection?

Answer 5

Free: heat flow due to temperature differences

Forced: heat flow due to an external force

Question 6

What is the equation for thermal radiation?

Answer 6

H_rad = Œσ(T_s⁴)

Question 7

What is Gular flutter?

Answer 7

Bird panting; a strategy for evaporative heat loss

Question 8

What are the involuntary methods of thermogenesis?

Answer 8

• shivering
• uncoupling proteins
• brown adipose tissue
• futile cycles

Question 9

What part of the hypothalamus manages temperature regulation?

Answer 9

pre-optic area (POA)

Question 10

What are the set point and sensors for temperature in the POA?

Answer 10

SP: temperature-insensitive neurons (Q₁₀ = 1)

warm-sensitive neurons (Q₁₀ > 1)

cold-sensitive neurons (Q₁₀ < 1)

Question 11

What is the function of motor neurons in thermoregulation?

Answer 11

connect hypothalamic neurons to effectors; integrate information from multiple hypothalamic neurons

Question 12

What is the function of PGE?

Answer 12

increase T_set in POA

[PGE] is increased by pyrogens

Question 13

What pyrogens increase PGE?

Answer 13

IL1; IL6 from white blood cells

LBS from exogenous sources

Question 14

What is the point of a fever?

Answer 14

increases the growth rate of gram+ bacteria, which use up the iron supply in the blood

subsequent lack of iron causes population crash