Q: Which equation best describes the relationship between temperature and the rate of chemical reactions in the body?

$$\text{Rate}_{\text{new}} = \text{Rate}_{\text{original}} \times 2$$^{\frac{\Delta T}$${10}}$$

Question 1

Which of the following mechanisms is primarily responsible for heat loss from the human body when sitting in a cool room, and why?

Accepted Answer

Radiation, because heat is emitted from the body as infrared waves to cooler surroundings.

Question 2

A person is submerged in a hot tub. Which mechanism of heat exchange is most enhanced in this scenario?

Accepted Answer

Conduction, because heat is transferred directly from the hot water to the body.

Question 3

Which equation best describes the relationship between temperature and the rate of chemical reactions in the body?

Accepted Answer

$$	ext{Rate}_{	ext{new}} = 	ext{Rate}_{	ext{original}} 	imes 2$$^{\frac{\Delta T}$${10}}$$

Question 4

During vigorous exercise, which organ system is responsible for the greatest increase in heat production?

Accepted Answer

Skeletal muscles

Question 5

Why is rectal temperature considered a better indicator of core body temperature than oral temperature?

Accepted Answer

The rectum is less affected by environmental temperature changes.

Question 6

Which of the following best explains why the hypothalamus is considered the major integrating center for thermoregulation?

Accepted Answer

It receives input from both central and peripheral thermoreceptors and initiates appropriate heat-loss or heat-promoting mechanisms.

Question 7

A person is exposed to cold weather for an extended period. Which sequence of physiological responses is most likely to occur to conserve heat?

Accepted Answer

Vasoconstriction, shivering, and increased thyroxine release

Question 8

Which of the following is an example of nonshivering thermogenesis?

Accepted Answer

Increased heat production due to brown adipose tissue metabolism stimulated by norepinephrine

Question 9

Why is evaporative heat loss less effective in a humid environment?

Accepted Answer

The air is already saturated with water vapor, reducing the rate of evaporation.

Question 10

A patient presents with a core body temperature of $$41^\circ C$$ and hot, dry skin. Which condition is most likely, and what is the underlying mechanism?

Accepted Answer

Heat stroke; hypothalamic heat-control mechanisms are depressed, leading to a positive feedback cycle

Question 11

Which behavioral modification would most effectively reduce heat gain on a hot, sunny day?

Accepted Answer

Wearing light-colored, loosely-fitting clothing

Question 12

Which of the following best describes the role of blood in thermoregulation?

Accepted Answer

Blood acts as a major heat transfer agent between the body core and shell.

Question 13

If a person loses 1.5 L of sweat per hour during vigorous exercise, approximately how much heat energy is removed from the body per hour? (Assume 0.5 kcal heat loss per gram of water evaporated; 1 L water = 1000 g)

Accepted Answer

$$1.5 	imes 1000 	imes 0.5 = 750$$ kcal

Question 14

Which of the following is NOT a mechanism of heat loss from the body?

Accepted Answer

Nonshivering thermogenesis

Question 15

Why is body cooling better tolerated than body heating during certain surgical procedures?

Accepted Answer

Lower temperatures slow metabolic reactions, reducing tissue damage risk.

Question 16

Which of the following statements about shell and core temperatures is correct?

Accepted Answer

Core temperature remains relatively constant, while shell temperature fluctuates widely.

Question 17

Which physiological response is most likely to occur when the shell temperature drops but the core temperature remains constant?

Accepted Answer

The hypothalamus initiates heat-promoting mechanisms to preserve core temperature.

Question 18

Which of the following best explains why wind increases heat loss from the body?

Accepted Answer

Wind enhances convection by moving warm air away from the body surface more rapidly.

Question 19

Which hormone is primarily responsible for increasing metabolic rate and heat production in response to chronic cold exposure in infants?

Accepted Answer

Thyroxine (T4)

Regulation of Body Temperature (Thermoregulation)

Study Guide - Practice Questions

Study Guide - Flashcards