zaterdag 28 september 2013
How do turtles breathe underwater?
Certain Sea Turtle species are breath holding champions! In regards to the structure of their respiratory system, sea turtles may more closely resemble marine mammals than they do other reptiles. Sea Turtles have the highest oxygen consumption rate of any reptile. Sea Turtles store high amounts of oxygen in blood and muscle tissue. Adult Leatherback Sea Turtles can dive deeply, holding their breath for up to 70 minutes. Loggerhead Sea Turtles have been known to survive for hours under anoxic (lacking oxygen) conditions, such an adaptation may assist in overwintering and hibernation activities. Sea Turtles appear to be extremely efficient at buffering the carbon dioxide in their blood, minimizing the effect of CO2 building up within their body system. A sea turtle's lung provides more area for gas exchange then other reptiles. All Sea Turtles have multi-chambered lungs full of spongy and elastic tissue providing large amounts of surface area for oxygen and carbon dioxide exchange; this allows sea turtles to exchange oxygen at a faster rate than any other reptile. Sea Turtles also have a strongly reinforced airway which is thought to help prevent airway collapse from the increased pressures encountered during deep diving. Sea turtles breathe by moving their pectoral and pelvic muscles (think of flapping your arms and legs), which compresses the area containing the lungs and changes the pressure within the lung cavity allowing both inhalation and exhalation to occur. Shallow diving, air-breathing organisms usually inhale before a dive and store most of the oxygen for that dive within their lungs. In contrast, the leatherback sea turtle is adapted to store much more of the oxygen it needs for deep diving within its blood and other tissues. This has the advantages of making oxygen more quickly available to the body cells and keeping it available even after lung collapse associated with a deep dive would normally have cut off those oxygen stores. All of this you learn during the Sea Turtle Awareness specialty. for more information: firstname.lastname@example.org