Temperature Regulation Flashcards
3 Sources of Heat Loss
Convection
Radiation
Conduction
Counter Current Heat Exchange
In cold, blood returns via deep veins next to arteries, so cool blood from periphery is warmed before going to heart and increasing insulation. In warmth, travels along cutaneous veins to reduce insulation/exchange heat w/ skin
Thyroxine
Increases basal metabolic rate
TRP Channels
Temperature receptors. Can be cold or warmth Rs, increasing AP freq for whichever it is
Temperature Sensing and Regulating Region
Pre optic area of ant hypothalamus and posterior hypothalamus, respectively
Temperature Regulating System
Cutaneous Temp Rs and Hypothalamic Sensory cells (measuring cutaneous and core temps, respectively) input to hypothalamic integrative cells, along with set point, which compares to set point and can initiate vasomotor, sweating, or shivering to adjust
Fever
Increase in set point, so w/ onset temp is below set point and person feels cold w/ shivering and chills. Then when breaks, person feels to hot and sweats/vasodilates
Fever Signaling Pathway
Bacterial release endotoxins/inf -> macs/other immune cells -> pyrogens -> prostaglandins (aspirin inhibits this production) -> raise set point
Reyes Syndrome
When aspirin given to children w/ viral illnesses, causing severe vomiting/lethargy and death and shit
Heat Exhaustion
Hypotension and fainting from overload in CV system from fluid loss/vasodilation. Core temp w/in normal limits
Heat Stroke
If body consistently produces more heat than it dissipates. 104+ are life threatening and 106+ cause brain daage
2 Kinds of Heat Stroke
Extertional heat stroke and non-exertional
Heaet Acclimatization (3)
Increased ability to vasodilate, and earlier onset/longer maintenance o sweating (w/ less salt too)
Cold Acclimatization (3)
Increased vasodilation, later onset of shivering, and increased production of thyroxine
