Skin and Temperature Regulation Flashcards
What is the core body temperature?
37 degrees +/- 0.5 degrees
When do proteins start to denature?
41 degrees Celsius
When do humans begin to lose consciousness?
Below 30 degrees
Define convection?
Fluid conduction hence why wind chill or water chill occurs
How does evaporation affect thermal balance?
Respiration and swearing causes 600ml of evaporation to occur. 4l/hour loss occurs at extremes
How does conduction affect thermal balance?
Heat transfer direct between touching objects
How does radiation affect thermal balance?
60% of heat is lost
Where are peripheral thermoreceptors located?
Located in the skin, especially in face and scrotum
Where are central thermoreceptors located?
Spinal cord, abdominal organs, hypothalamus
What do peripheral thermoreceptors detect?
Changes in environmental temperature?
What do central thermoreceptors detect?
A change in core body temperature
How is heat generated within the body in response to cold stress?
General metabolism increases heat by oxidative phosphorylation, voluntarily moving muscles, shivering thermogenesis and nonshivering thermogenesis in brown adipose tissue in infants
How is heat lost from the body during cold stress?
Vasomotor control - arteriolar constriction reduces delivery of blood to the skin, Behavioural Response causes us to add clothing or move to warmer environments
Who is at risk for hypothermia?
Neonates, Elderly, vagrants, cold store workers, north sea workers, outdoor pursuits
How is hypothermia treated?
Dry/Insulate to prevent heat loss, slow re-warming with bag/blankets, internal re-warming with hot drinks and/or warm air, fast re-warming by immersion in water, extracorporeal circulation
What is the vascular cause of frost bite?
Vasoconstriction, increase in viscosity, promotes thrombosis, causes anoxia
What is the cellular cause of frost bite?
Ice crystals form in Extracellular Space, increases extracellular osmolality, causes movement from Intracellular Space and this causes dehydration and death
What occurs in heat exhaustion?
Body temp raises to 37.5-40 degrees, results in vasodilation and drop in central blood volume. Is caused by a disturbance of the body’s fluid/salt balance due to excessive sweating.
What are the symptoms of heat exhaustion?
Headache, confusion, nausea, profuse sweating, clammy skin, tachycardia, hypotension, weak pulse, fainting and shock
What occurs in heat stroke ?
Body temp rises above 40 degrees, body temp control mechanisms fail,
What are the symptoms of heat stroke?
Hot dry skin and circulatory collapse
Who are most at risk of heat stress?
Neonates and the elderly, labourers in hot weather
What is a fever?
Part of the bodys mechanism for fighting infections caused by endogenous pyrogens (IL-1, IL-6)
