thermoregulation (emily)
what is the normal body temperature
36.2-37.6
what part of the body is known as the thermostat
the hypothalamus
what is the term for when the body is above normal temperature
hyperthermia
what is the term for when the body is at an extreme high temp
hyperpyrexia
what is chemicothermogenesis
when there is an increase in metabolic rate due to epinepherine
what do thermoreceptors in the skin detect to trigger heat loss responses
an increase in temperature
what are the heat loss responses triggered by increased blood temperature
vasodialation of capillaries
sweating
decreased metabolic rate
what do thermoreceptors in the skin detect to trigger heat conservation responses
a fall in temperature
what are the heat conservation responses triggered by decreased blood temperature
vasoconstriction of capillaries
shivering
erector pilli muscles contracting (hair stands up)
increased metabolic rate
which part of the body monitors blood temperature to maintain thermoregulation
the central thermoreceptors in the hypothalamus
how is thermoregulation linked in infants
closely connected to metabolism and oxgen consumption
what type of fat helps infants regulate temperature
brown fat
how does non-shivering thermogenesis help infants
it offsets heat loss by increasing metabolism and oxygen consumption
what posture helps newborns minimize heat loss
fetal position, reduces surface area
why do infants have limited insulation
they have a thin layer of subcutaneous fat
slower circulation, reduced thermoregulatory capacity of the skin, reduced heatproduction, and decreased shivering response are factors that affect thermoregulation in what population
older adults
what are thermoregulagion risk factors for children
cannot independently adjust to regulate their temperature
how is alcohol a risk factor
it is a vasodialator and may not recognize temperature
what is a pyrogen
a fever-producing agent triggering the hypothalamus to adjust heat and maintain core body temperature
how do pyrogens affect the hypothalamus
increase the hypothalamic set point, causing the body to elevate its temperature
what is a fever
natural response of the body to physiological stress, characterized by an elevation in body temperature due to a change in the hypothalamic set point
what causes the change in the hypothalamic set point during a fever
inflammatory cytokines and mediated by pyrogens acting on the hypothalamus
what are 2 types of pyrogens
endogenous : cytokines produced inside the body (IL-1, IL-6, and TNF)
exogenous : toxins from outside the body (bacterial or viral toxins)
true or false: fevers can only be caused by infectious conditions
false, can be infectious and non-infectious
what are signs and symptoms of a fever
diaphoresis, shivering, pale, flush, warmth, and syncope
which area of the body is closest to core temperature
rectal temperature
what measures can reduces fevers
antipyretics and an increase in fluid intake
what is the key difference between a fever and hyperthermia
hyperthermia= body temp above 37.6 with an unchanged hypothalamic set point
what is the cause of hyperthermia
excessive heat from surroundings or an increase in the internal heat production
what are neurogenic causes of hyperthermia
brain trauma, ischemic/hemorrhagic stroke, increased intracranial pressure
what is an endocrine cause of hyperthermia that can lead to severe hypertension
pheochromocytoma
what can a thyroid storm lead to
tachyarrhythmias like A.fib
hypotension, hyponatremia, hyperkalemia in Addisons disease are examples of ______ _____ as an endocrine cause in hyperthermia
adrenal crisis
what type of drug-induced reaction to hyperthermia is unpredictable regardless of the dose of the drug
idiosyncratic reaction
what is hypothermia
when the core body declines below 36.2 and results in excessive heat loss, insufficient production of heat
removing excess clothing, providing a cooling blanket or cool packs are interventions for:
hyperthermia
what are the cardiovascular consequences of hypothermia
arrythmias secondary to potassium loss and increased plasma viscosity
how does hypothermia affect coagulation
impairs coagulation and reduces platelet count
what are renal and metabolic effects caused by hypothermia
reduced glomerular filtration rate
metabolic acidosis
hyperglycemia secondary to glucose metabolism
effects on pharmacodynamics and pharmacokinetics
what are the cerebral consequences of hypothermia
vasoconstriction during cooling and brain injury from hyperthermia during rewarming
what are consequences of hypothermia
reduced perfusion, peripheral vasoconstriction, and reduced cognition
what are cardiovascular consequences of elevated body temperature
hypotension, tachycardia, decreased CO, reduced perfusion, and coagulation
sodium loss, dehydration, cerebral edema, degeneration of central nervous system, and renal necrosis are consequences of:
elevated body temperature
in what 4 modes does heat loss occur
convection, radiation, evaporation, and conduction
what are environmental influences of heat loss
temperature, humidity, flow, and velocity of the air
what are 3 consequences of cold stress in thermoregulation in pre-term infants
hypoxia, metabolic acidosis, hypoglycemia
how might a low body weight infant appear when experiencing thermoregulation
smaller muscle mass, less brown fat, poor reflex control
what is an indicator of hyperthermia in infants
apnea and a flushed colour
an increase in oxygen and calorie consumption is produced in:
overheating
in healthy term infants what is the recommended axillary temperature
36.5-37.5
what is the normal axillary temperature in preterm/at-risk newborns
36.3-37.2
how often should you monitor axillary temperatures postpartum
every 30 mins until stable, then every 1-4 hours
when should you bathe an infant postpartum
after thermal stability is maintained for 1hr
what are results of infants being swaddled in too many blankets
skin vessles dilate, flushed skin, warm hands and feet
constricted vessels in skin, pale, and cold hand and feet might be sign of a newborn who is:
hyperthermic because of sepsis
what can hyperthermia cause in infants
dehydration causing cerebral damage, heat stroke, and death