BIOL 111 Lecture Notes - Lecture 20: Thermoregulation, Bipedalism, Keratin

• School: McGill University
• Department: Biology (Sci)
• Course: BIOL 111
• Professor: Rajinder Dhindsa

Document Summary

Biol 111-lecture 20-birds (more reptiles: ancestor of birds dinosaur, shared characteristics of birds and dinosaur. -parental care of eggs and juveniles: archaeopteryx ( ancient wing ) -non-avian characters (teeth & bony tail: birds (aves, amniotes, endothermic, 4-chambered heart & separate pulmonary & systemic circuits, feathers, most fly, diverse beaks adapted for diverse diets e. g. darwin"s finches, thermoregulation (body temperature control, source of body heat. -generate internal heat through metabolic processes: temporal variation of body temperature. -body temperature depends on environmental temperature: mechanisms to maintain body temperature. -orientation relative to heat source, basking, huddling & varying contact with heat surface. -too hot: increase blood flow to periphery, panting, sweating. -too cold: decrease blood flow to periphery, shiver. *flying & endothermy demand large amount of o2, system is much more complex. & efficient: unidirectional flow of air though lungs, use of numerous air sacs. Sternum enlarged and keeled increases surface area for attachment of large flight muscles.