Lecture 8 Thermoregulation In Children & Adults

Question 1

Which of the following stuff regarding thermoregulation in children versus adults is incorrect?

A) at a given work rate, children generate more heat per kg of body mass than adults
B) children have a relatively larger body surface area for dissipating heat
C) sweating rate is significantly greater in children than adults
D) children rely more on convective heat loss from increased cutaneous blood flow

Answer 1

C) sweating rate is significantly greater in children than adults

Question 2

Name factors that contribute to the reduced ability of older adults to thermoregulate during cold stress and heat stress

Answer 2

Older adults under cold stress:

• less shivering
• less peripheral vasoconstriction
• lower resting metabolic heat production
• sarcopenia

Older adults under heat stress:

• lower cutaneous perfusion/ inability for peripheral vasodilation
• smaller increase in cardiac output/ stroke volume
• less redistribution of blood flow from renal and sphlanchnic regions

Question 3

Children have more effective heat loss via convection than adults because of their:

a) Greater density of sweat glands
b) Large blood vessels
c) Sensitivity to changes in temperature
d) Greater body surface area relative to body mass

Answer 3

d) Greater body surface area relative to body mass

Question 4

Older adults are less effective at maintaining their core body temperature during cold stress due to less peripheral vasoconstriction and less metabolic
heat generation through:

a) hyperventilation
b) activation of the parasympathetic nervous system
c) shivering
d) the chemoreflex

Answer 4

c) shivering

Question 5

When comparing the responses to heat stress
between young and older adults, which of the
following is false?
a) Older adults sweat less
b) Older adults have lower levels of skin blood flow
c) Older adults have a smaller increase in cardiac output
d) Older adults have more effective blood flow
redistribution

Answer 5

d) Older adults have more effective blood flow redistribution

Question 6

Which of the following statements about sweating is
false?
a) The number of sweat glands is fixed early in infancy.
b) The density of sweat glands on the skin increases
with age.
c) An increase in body surface area is associated with
an increase in the output from each sweat gland.
d) Sweat rate per gland is positively correlated with
pubertal status.

Answer 6

b) The density of sweat glands on the skin increases with age

Question 7

Which of the following is a physiological adaptation
that results from heat acclimatisation?
a) Increase in resting core temperature
b) Decrease in the temperature threshold for
vasodilation at the skin
c) Decrease in resting and maximal stroke volume
d) Increase in resting heart rate

Answer 7

b) Decrease in the temperature threshold for vasodilation at the skin

Question 8

In the study by Gonzalez-Alonso (1999), cyclists
exercising in the heat fatigued at what point?
a) All fatigued once they reached 60 minutes of
exercise.
b) All fatigued at the same critical core temperature
of 40.1- 40.2 degrees Celcius.
c) All fatigued when they reached maximal sweat
rates.
d) All fatigued when skin temperature exceeded
ambient air temperature by 10 degrees Celcius.

Answer 8

b) All fatigued at the same critical core temperature of 40.1- 40.2 degrees Celcius.