ANT202H5 Lecture Notes - Lecture 16: Weight-Bearing, Vasoconstriction, Vasodilation
Document Summary
Ant202 lecture 17 nov 24th, 2016 (continuation of previous lecture) Energy sparring adaptive mechanisms during pregnancy and lactation: reduction of energy during physical activity, work efficiency increased/ increase body weight/ increase weight bearing activity, efficient utilization of energy resources, inhibition of diet-induced thermogenesis. Increase in metabolic rate after food ingestion not seen in undernourished. Reduced dit for 1st 3 months of lactation: increased efficiency of dietary energy absorption. Vasoconstriction: blood vessels narrow to reduce blood flow and heat loss. Vasodilation: blood vessels open to increase blood flow and heat loss. Hunting reaction: alternating vasoconstriction and dilation in extremities exposed to cold. Radiation heat flow through electromagnetic radiation. Convection heat flow through air molecules. Conduction heat exchange through physical contract with other objects. Evaporation heat loss through conversion of water to vapor: only process that results in heat loss w/o heat gain. Ant202 lecture 17 nov 24th, 2016. Vasodilation increased transfer of internal heat to surface: radiation, convection and evaporation.