REGULATION OF BODY TEMPERATURE+Discuss the role of effectors
(muscles and glands) in regulation body temperature in cold
environment.
+A) action of hair erector muscleHair erector muscles are
stimulated to contractHairs become erect/standTrap a thick layer of
air, prevent heat loss by conduction and radiationB) Action of
blood capillariesVasoconstriction occurs, blood capillaries
constrictsLess blood flows close to the body surfaceHeat loss by
conduction and radiation is reduced.C) Action of sweat glandsSweat
gland inactiveLess sweat producedRate of evaporation very lowHeat
is conserved.+D) action of musclesVoluntary muscular activity
increased such as rubbing handsInvoluntary muscles contract and
relax frequently leading to shiveringE) Action of adrenal
glandAdrenal gland stimulate the secretion of adrenaline which
causes the increase in metabolic rateMore heat is produced.F)
Action of thyroid glandThyroid gland is stimulated to secrete
thyroxineMetabolic rate increasedMore heat is produced.+Discuss the
role of effectors in regulation body temperature in warm
environment.
