4.5.2.4 Control of body
temperature
By the end of this module you
understand / be able to:
• Body temperature is monitored and controlled by the
thermoregulatory centre in the brain. The thermoregulatory centre
contains receptors sensitive to the temperature of the blood. The
skin contains temperature receptors and sends nervous impulses to
the thermoregulatory centre.
• If the body temperature is too high, blood vessels dilate
(vasodilation) and sweat is produced from the sweat glands. Both
these mechanisms cause a transfer of energy from the skin to the
environment.
• If the body temperature is too low, blood vessels constrict
Why is it so important for human body temperature to be
maintained at 37oC?
Because temperature is directly linked to enzyme controlled
reactions, such as digestion, which happen all around our body and
if the temperature would be lower, those reactions wouldn’t
happen fast enough and the person would die; same as if the
temperature would get too high, the enzymes would start
denaturing and the person would also die
Thermoregulatory Centre
Core body temperature is monitored by the thermoregulatory centre, located in the
hypothalamus of the brain. The thermoregulatory centre contains receptors
sensitive to the temperature of the blood. The skin contains temperature receptors
and sends nervous impulses to the thermoregulatory centre.
, Anatomy of the skin (just need to be aware of sweat glands, hairs and
blood vessels)
Vasoconstriction & Vasodilation
VASOCONSTRICTION –
explain what is going on in the
diagram below, when the core
body temperature drops too
low
- Skin capillaries constrict
(get narrower) in order to
reduce the flow of blood
next to the surface by
capillaries
- Less heat will be lost from
the surface of the skin via
radiation
VASODILATION – explain
what is going on in the diagram
below, when the core body
temperature gets too high?
temperature
By the end of this module you
understand / be able to:
• Body temperature is monitored and controlled by the
thermoregulatory centre in the brain. The thermoregulatory centre
contains receptors sensitive to the temperature of the blood. The
skin contains temperature receptors and sends nervous impulses to
the thermoregulatory centre.
• If the body temperature is too high, blood vessels dilate
(vasodilation) and sweat is produced from the sweat glands. Both
these mechanisms cause a transfer of energy from the skin to the
environment.
• If the body temperature is too low, blood vessels constrict
Why is it so important for human body temperature to be
maintained at 37oC?
Because temperature is directly linked to enzyme controlled
reactions, such as digestion, which happen all around our body and
if the temperature would be lower, those reactions wouldn’t
happen fast enough and the person would die; same as if the
temperature would get too high, the enzymes would start
denaturing and the person would also die
Thermoregulatory Centre
Core body temperature is monitored by the thermoregulatory centre, located in the
hypothalamus of the brain. The thermoregulatory centre contains receptors
sensitive to the temperature of the blood. The skin contains temperature receptors
and sends nervous impulses to the thermoregulatory centre.
, Anatomy of the skin (just need to be aware of sweat glands, hairs and
blood vessels)
Vasoconstriction & Vasodilation
VASOCONSTRICTION –
explain what is going on in the
diagram below, when the core
body temperature drops too
low
- Skin capillaries constrict
(get narrower) in order to
reduce the flow of blood
next to the surface by
capillaries
- Less heat will be lost from
the surface of the skin via
radiation
VASODILATION – explain
what is going on in the diagram
below, when the core body
temperature gets too high?
