Hypothalamic thermoregulation The temperature regulation of the body is an essential factor for the survival in mammals. The key role in these processes play the hypothalamus, the part of the brain that links the nervous system with the endocrine system (everything related to hormonal messengers). Depending on the sensation that sensors across our body transmit to the hypothalamus, cooling or heating can be induced.
If critically high temperatures are sensed, the following effects are induced: Sweating (to cool the skin by evaporation of water from the surface) and vasodilation (widening of blood vessels to transport more blood to the skin where the body loses heat through radiation). If critically low temperatures are sensed, the following effects are induced: Vasoconstriction (narrowing of blood vessels leads to reduction of blood flow in the extremities to keep the warm blood closer to the vital organs), shivering (heating through increased muscle movement) and hormonal thermogenesis (where the thyroid gland releases hormones to upregulate the metabolism). The complex interaction of all factors in hypothalamic thermoregulation is still not fully elucidated. Take home message for this course is the fact that the low temperature sensation triggers a cascade to induce fever via biosynthesis of prostaglandines. COX inhibitors suppress the eicosanoid biosyntesis and thus help against critically high fever. |