Dolpin (6) Flashcards
(30 cards)
What happens to baleen whales’ lungs at great depths?
Whales’ lungs collapse, but their ribs do not break.
Why do whale ribs not break under pressure?
The cetacean rib cage is less rigid/more flexible than that of land mammals.
- What is the significance of fats in whale blood?
- What does this help to avoid?
- They reduce the quantity of dissolved nitrogen available to nerve membranes.
- This reduces nitrogen narcosis/raptures of the deep (where you pass out from breathing in too much nitrogen in high pressure air).
How do whales eliminate excess nitrogen from their airways?
With a phlegm of fat droplets in the expired air when they surface.
What percentage of their lung capacity do whales fill with each breath?
About 90 percent.
How does whale lung capacity compare to terrestrial mammals?
Terrestrial mammals fill about 20 percent of their lung capacity.
What allows whales to take in more oxygen per breath?
They have more hemoglobin in their blood.
How does whale blood chemistry differ from that of land mammals?
Whale blood is slightly more acidic, allowing for more efficient oxygen transfer.
What temperature difference can whales face in the sea?
As much as 16 degrees Celsius lower than their own temperature.
What is the counter-current heat exchange system that’s found in whales?
A system that allows warm arterial blood to relinquish heat to incoming veins.
How does the counter-current heat exchange system help whales?
It reduces heat loss to the surrounding water.
How did the return of whales’ ancestors to the sea affect their bone structure?
They no longer needed structural support of heavy bones
What constraints on size did water’s supportive properties remove for whales?
Gravitational restraints
What is the weight comparison between a blue whale and an elephant?
A blue whale is heavier than 20 elephants
What limits the size of a whale species?
Food supplies available to its lineage
How do large whales and small whales differ in their feeding strategies?
Large whales feed on large quantities of small prey; small whales feed on smaller numbers of larger prey
True or False: All species of whales communicate and form social groups.
True (at least for some parts of their lives)
At what depth does darkness prevail in the sea?
Below about 500 feet (150 meters)
How does sound travel in seawater compared to air (in terms of speed)?
About five times the speed of sound in air
What causes sound waves to bend or refract in water?
Differences in temperature, pressure, or salinity
What effect causes shifts in the frequencies of the echos when either the target or echolocation is moving?
Doppler effect
What kind of information can the Doppler effect yield?
Relative speed and orientation of objects in three dimensions
What does the social chattiness of whales suggest about their communicative ability?
It may be better than our own in terms of information communicated and speed of transmission
What is the doppler effect?
Where there are shifts in the frequencies of echolocation sounds (changes in Hertz/Hz) that are caused by a target moving.
