Module 8.4: Thermoregulation

Question 1

Body temperature is homeostatically regulated by the ________

Answer 1

Body temperature is homeostatically regulated by the hypothalamus

Question 2

The ____ _______ coordinates the response to decreases in body temperature, whereas the ____ _______ coordinates the response to increases in body temperature

Answer 2

The posterior hypothalamus coordinates the response to decreases in body temperature, whereas the anterior hypothalamus coordinates the response to increases in body temperature

Question 3

Thermal information is detected by

• _____ ______ located in the hypothalamus, central nervous system, and abdominal organs
• by ____ ______ located in the skin.

Answer 3

Thermal information is detected both by

• central thermoreceptors located in the hypothalamus, central nervous system, and abdominal organs and by
• peripheral thermoreceptors located in the skin.

Question 4

Thermal information is integrated and compared to a set point in the ______\_, which then relays ______\_ information to the effectors in response to deviations from the set point

Answer 4

Thermal information is integrated and compared to a set point in the hypothalamus, which then relays efferent information to the effectors in response to deviations from the set point

Question 5

Homeostatic control system for temperature regulation.

Answer 5

Homeostatic control system for temperature regulation.

Question 6

Coordinated adjustments to both _____ ______ and ____ _____ occur in response to decreases and increases in internal core temperature

Answer 6

Coordinated adjustments to both heat production and heat loss occur in response to decreases and increases in internal core temperature

Question 7

How is heat production increased in response to cold exposure (by the Posterior Hypothalamus)? (4)

Answer 7

1. Increased muscle tone
2. Shivering
3. Increased voluntary exercise
4. Nonshivering thermogenesis

Question 8

How is heat loss decreased (ie heat conservation) in response to cold exposure (by the Posterior Hypothalamus)? (3)

Answer 8

1. Skin vasoconstriction
2. Postural Changes to reduce exposed surface area
3. Warm clothing (behavioural adaptation)

Question 9

How is heat production DECREASED (by the Anterior Hypothalamus) in response to heat exposure? (2)

Answer 9

1. Decreased muscle tone
2. Decreased voluntary exercise (behavioural)

Question 10

How is heat loss INCREASED in response to heat exposure (by anterior hypothalamus)? (3)

Answer 10

1. Skin vasodilation
2. Sweating
3. Cool clothing (behavioural)

Question 11

What is Hyperthermia?

Answer 11

A prolonged increase in body temperature above the normal range and beyond the body’s ability to compensate

Question 12

Hyperthermia may result physiologically from _____ or pathophysiologically from abnormalities associated with the ______ or ___________

Answer 12

Hyperthermia may result physiologically from exercise or pathophysiologically from abnormalities associated with the hypothalamus or metabolic rate

Question 13

Heat exhaustion involves a drop in ________ and results from overactivity of the body’s ________ such that body temperature ______ despite the normal compensatory mechanisms such as sweating and vasodilation

Answer 13

Heat exhaustion involves a drop in blood pressure and results from overactivity of the body’s heat loss mechanisms such that body temperature increases despite the normal compensatory mechanisms such as sweating and vasodilation

Question 14

Heat stroke is a more dangerous than _______

It is condition that results from a breakdown of the _______ ability of the hypothalamus such that body temperature _______ in the absence of the normal compensatory mechanisms

Answer 14

Heat stroke is a more dangerous than heat exhaustion.

It is condition that results from a breakdown of the thermoregulatory ability of the hypothalamus such that body temperature increases in the absence of the normal compensatory mechanisms

Question 15

Hyperthermia does not include fever.

Fever is an increase in body temperature that results from an ________ to _____ or _______ and involves the release of ___________ from ______.

Answer 15

Hyperthermia does not include fever.

Fever is an increase in body temperature that results from an immune response to infection or inflammation and involves the release of endogenous pyrogens from macrophages.

Question 16

are responsible for changing the set point of the hypothalamus

Answer 16

endogenous pyrogens are responsible for changing the set point of the hypothalamus

Question 17

In a fever, the hypothalamus initiates compensatory mechanisms that increase internal body temperature to match the ______\_set point caused by ________\_

Answer 17

In a fever, the hypothalamus initiates compensatory mechanisms that increase internal body temperature to match the altered (increased) set point caused by endogenous pyrogens

Question 18

Figure 8.4.2 – Mechanism of fever.

How is a fever brought about?

Answer 18

Figure 8.4.2 – Mechanism of fever.

Question 19

_______\_ is a prolonged decrease in body temperature below the normal range and beyond the body’s ability to compensate

Answer 19

Hypothermia is a prolonged decrease in body temperature below the normal range and beyond the body’s ability to compensate

Question 20

_____\_ refers to tissue damage associated with excessive cooling of the skin and the underlying tissue

Answer 20

Frostbite refers to tissue damage associated with excessive cooling of the skin and the underlying tissue

Question 21

In more extreme cases of frostbite, cellular death takes place due to___________ or a ________\_

Answer 21

In more extreme cases of frostbite, cellular death takes place due to ice crystal formation or a lack of liquid water