Thermoregulation and Fever

Question 1

The body core temperature remains very constant within ____

Answer 1

+/- 1°F
(+/- 0.6°C)

Question 2

The ____ rises and falls with the temperature of the surroundings

Answer 2

skin temperature

Question 3

The average normal core temperature is:

Answer 3

98.0° - 98.6°F orally

Question 4

Body temperature ____ when the rate of heat production in the body is greater than the rate of heat loss

Answer 4

increases

Question 5

Body temperature ____ when the rate of heat production in the body is less than the rate of heat loss.

Answer 5

decreases

Question 6

Heat production, also called the metabolic rate of the body, is influenced by various factors

Answer 6

○ Basal rate of metabolism
○ Muscle activity (including shivering)
○ Thyroxine, and other hormones
○ Epinephrine, norepi, and sympathetic metabolism of the cells
○ Increased cellular chemical activity
○ Digestion, absorption, and storage of food (thermogenic effect of
food)

Question 7

Heat loss is determined by

Answer 7

○ How rapidly heat can be conducted from where it is produced in the body core to the skin
○ How rapidly heat can be transferred from the skin to the surroundings

Question 8

Heat loss from skin to surroundings occurs by

Answer 8

○ Radiation
○ Conduction
○ Evaporation
○ Convection

Question 9

Thermoregulatory Set Point - an
important temperature level at which the
body works to maintain a balance between
____ and ____.

Answer 9

heat production and heat loss

Question 10

The body temperature of humans changes ____°C for each 25-30°C change in environmental temperature

Answer 10

1

Question 11

____ set point is the temperature set-point where above sweating begins and below shivering begins

Answer 11

Hypothalamic

Question 12

The ____ is the most effective mechanism for heat transfer from the body core to the skin

Answer 12

flow of blood to the skin

Question 13

The sweat gland has two parts

Answer 13

○ A deep coiled portion that secretes sweat
○ A duct portion that passes outward

Question 14

There are _____ located in other parts of the body, specifically the skin and some deep tissues (including spinal cord, abdominal viscera)

Answer 14

temperature receptors

Question 15

T/F The skin has cold and warmth receptors.

Answer 15

T

Question 16

T/F the skin has many more cold receptors than hot

Answer 16

T - focus on preventing hypothermia.

Question 17

There are several mechanisms the body uses to reduce body heat if body temperature is too great

Answer 17

Vasodilation of skin blood vessels
Sweating
Decrease in heat production

Question 18

reflexes to increase the body temperature:

Answer 18

○ Causes shivering (increases rate of body heat production)
○ Inhibits sweating
○ Promotes skin vasoconstriction (diminishes loss of body heat from
skin)

Question 19

______- traps a layer of “insulator
air” next to the skin so less heat is
transferred to surroundings (more
important in animals)

Answer 19

Piloerection

Question 20

There are several mechanisms the body uses to increase body heat
if body temperature is too low:

Answer 20

Skin vasoconstriction
Piloerection
Increase in heat production (thermogenesis)

Question 21

_____ - area of activation is located in the posterior hypothalamus

Answer 21

Shivering

Question 22

Circulating epinephrine or norepi can cause an increase in the rate of _____

Answer 22

cellular metabolism

Question 23

_____ - a body temperature higher than normal. Can be caused by brain abnormalities or toxic substances that affect the temperature regulating centers

Answer 23

Fever

Question 24

With fever, Various substances, called _____, can cause the set-point of the hypothalamic thermostat to rise.

Answer 24

pyrogens

Question 25

____ (an antipyretic) impedes the
formation of prostaglandins

Answer 25

Aspirin (f prostaglandin formation is blocked by medications, the fever is reduced.)