is this labelled correctly? as an undergraduate a substantially more impressive response is required, what do you know so far?
you would need to include the relative significance of different heat loss mechanisms, the role of polymodal C-fibre sensory receptors and ascending spinal pathways. The role of behavioural changes related to temperature via the somatosensory cortex. The role of the hyopothalamic nuclei in both sensing temperature (anterior, preoptic), paraventricular and sympathetic outflow and supraoptic/paravent in initiating endocrine axes (TRH etc). Autoregulation of cutaneous vasculature in addition to the role of the SNS outflow (incl. reduced sweating). could add in some pathologies such as hypothermia (incl. ecg changes etc), frostbite/trenchfoot and Raynaud's.
that makes no sense at all, the efficiency of mechanical work is around 20% but in what way does that describe the mechanism of involuntary contraction-relaxation cycles of skeletal muscle specific to cold? it doesn't, shivering is a different phenomena.
(Original post by thegodofgod)
Shivering occurs because the aerobic respiration in muscles is very inefficient (only around 20% efficiency, I think), meaning a lot of heat is lost and less ATP is generated. The heat loss from respiration is what is used to heat you up.
heat loss from respiration is an interesting one especially in light of the role of brown adipose, the thyroid hormones and the sympathetic innervation (esp in babies). are you edexcel? if so your case study briefly touches on this kind of thing.
Last edited by John Locke; 05-04-2012 at 20:11.