Thermoreceptors are:
activated only by severe cold or severe hot
located on the superficial layers of the skin
a subtype of nociceptors
on dendritic endings of A6 fibres and C fibres
all of the above
The most significant heat source in the body is:
cellular respiration
conductive heat loss
convective heat loss
evaporation
shivering
A major means for conserving heat is:
vasodilatation of coetaneous blood vessels
increased metabolic rate
vasoconstriction of coetaneous blood vessels
enhanced sweating
increased convective loss
The thermoregulatory center is located in:
cortex
vascular system
septal region
amygdale
hypothalamus
What is the normal body temperature?
81.1°C
36.9°C
98.6°C
21.7°C
39.5°C
At which temperature does the excitation of the thermoreceptors begin to cause pain?
at the temperature which causes tissue damage
over 45°C
at 30°C
at 5°C
b, and d
Heat stroke is characteristically associated with:
profuse sweating
elevated basal metabolic rate
hot dry skin
a and b
b and c
As ambient temperature increases, heat loss increases by:
radiation
convection
conduction
none of the above
Which of the following is not a function of skin?
respiration
excretion
sensation
thermoregulation
protection
Following adaptation to a hot climate there is an increase in:
basal metabolic rate
heat loss by radiation and convection
urinary output
the ability to lose heat by sweating
decreasing arteriovenous shunting of blood to venous plexus near the surface of the skin
Heat - loss mechanisms:
by radiation and convection increase when the ambient temperature decreases
by evaporation; depend on the activity of sweat glands being under sympathetic muscarinic control
are controlled by the anterior hypothalamus
cause an increase in sympathetic tone to skin blood vessels
decrease arteriovenous shunting of blood to venous plexus near the surface of the skin
The set-point temperature of the hypothalamus, triggering heat - loss or heat - generating mechanisms is:
34° C
37° C
20° C
36.3° C
30° C
When the temperature of environment is above 34°C, the only heat-loss mechanism is:
radiation and convection
The set point level for body temperature is situated in:
anterior hypothalamus
skin
spinal cord
posterior hypothalamus
brown mast tissue
The most potent mechanism for increasing heat production is:
activation of the parasympathetic nervous system
thyroid hormone increasing the metabolic rate
decrease in sympathetic tone to skin blood vessels
