Skin And Temperature Regulation Flashcards
What is the normal core body temperature?
37 +/- 0.5
Why does our core body temperature have to stay within a narrow range?
Because over 41 degrees proteins start to degenerate
And below 30 degrees we start to lose conciousness
Where are the central and peripheral thermoreceptors located?
Central - spinal cord, abdominal organs, hypothalamus
Peripheral - skin, especially face and scrotum
Where does information from the peripheral and central thermoreceptors send information to?
Hypothalamic thermoregulatory center
How is heat that is generated by the body increased?
General metabolism
Voluntary muscular activity
Shivering thermogenesis
Non shivering thermogenesis (infants)
How is heat loss from the body reduced?
Vasomotor control - sympathetic arteriolar constriction reducing delivery of blood to the skin
Behavioural reponses
What is hypothermia ?
Drop in core body temp below 35
Who are at risk of hypothermia?
Neonates Elderly Cols store workers Outdoor pursuits North sea workers etc
What is the treatment for hypothermia?
Dry / insulate to prevent further heat loss
Slow re warming with blankets
Fast re warming by immersion in water
Internal re warming with hot drinks / warm air
How does frost bite occur as a response to cold stress?
Cold causes vasoconstriction and incrreased viscosity which promotes thrombosis = anoxia
Ice crystals form in the extracellular spaces which increases extracellular osmolarity. This causes movement of water from intracellular space = cell dehydration & death
Why is there an increase in strokes and heart attacks in the winter months?
Cold weather = vasodilatation and increased viscosity = thrombosis = ischaemia
How is heat production minimised?
Reduced food intake
Decreased physical activity
How is heat loss from the body increased?
Vasomotor control - arteriolar dilation
Sweating - sympathetic cholinergic fibres increase evapourative heat loss
Behavioural responses
At what body temperature results in heat exhaustion?
37.5 - 40
How does heat exhaustion occur?
Body temperature rises there is a disturbance in the bodys fluid/salt balance due to excessive sweating
What are the symptoms of heat exhaustion?
Headache Confusion Nausea Profuse sweating Tachycardia Hypotenion (arteriolar dilatation = drop in central blood volume) Clammy skin Weak pulse Fainting & collapsing
What is heat stroke?
Body temperature raised above 40 and it causes the bodys temperature control mehcnaisms to fail
What are the symptoms of heat stroke?
Hot, dry skin
Circulatory collapse
Who are most at risk of heat stroke / heat exhaustion?
Neonates and elderly
People doing physical work in humid environments
What is the treatment for heat stroke?
Fluids
Fan
Sponge with tepid water
What is repsonsible for causing fever when our body is fighting infection?
Endogenous pyrogens
They cause local production of prostaglandin’s by cyclo-oxygenase in the hypothalamus
