SLE204 Lecture Notes - Lecture 4: Thermogenesis, Stapes, Deciduous Teeth
9 Aug 2018
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Phylum: chordata class: mammalia: subclass synapsida origins of mammals. 1 temporal opening behind occipital orbit associated with attachment of jaw muscles. Single jaw bone; large gape; specialised teeth. Endothermy: keep internal environment at 36-38 degrees, maintain constant body temp (homeothermy) by balancing heat produced by metabolism with heat loss to the environment, adaptations for hot environments (e. g. desert) Small animals live in ground (fossorial) or are nocturnal --> to escape the heat. Living in burrows --> higher humidity -> reduces water loss via evaporation. Glossy, pale fur to reflect direct sunlight. Heat lost by convection (air movement) and conduction from the underside of animal where fur is thin. Panting and sweating to reduce internal temp. Produce highly concentrated urine (retains water) and dry faeces. Long loop of henle (maximise water absorption) Body temp drops during cool nights to reduce water loss thru evaporation.
