BIOLOGY 2A03 Lecture Notes - Lecture 66: Marine Mammal, Cytoglobin, Neuroglobin
Document Summary
Diving mammals don"t have gills - have to hold breath for long periods under water while exercising. Flexible ankle/wrist joints able to walk on land. Large, extended, flattened fore flippers, used for swimming rely on pectoralis muscles to propel under water. Fur absent on underside of fore flippers like to be outside water so this absence of fur helps grip on rocky coasts better. No external pinnae can still hear, just don"t have funnel flap. Ankle/wrist joints not flexible use undulatory motion on land (similar to worm, but still fast) Small fore flippers; hind flippers used for swimming. Fur on entire fore flipper & terminal claws ice surfaces. Difference between terrestrial exercise response and dive response: Increased ventilation: increasing movement of oxygen throughout body; increased breath. Increased heart rate (tachycardia) moving more blood throughout body. Peripheral vasoconstriction: decreasing blood flow and oxygen + metabolite delivery. Diving mammals have special adaptations for breath-hold exercise.