Essay on Physiology: Sharks

Submitted By Josh-Schaefer
Words: 574
Pages: 3

Physiology




Shark ears are just two small openings behind and above the eyes. They may be small, but they’re powerful. Each ear has cells that can sense even the most minute vibration in the surrounding water. Sharks also have an ‘ear stone’ that responds to gravity, telling the shark its position in the water
Although its heart and gills operate at water temperatures, portions of the Great White's circulatory system have adapted to hold body heat longer. On its way back to the heart, blood inside the veins is heated by muscle contractions. The heat is transferred to the blood as it passes through a tightly-intermeshed network of veins and arteries. These veins and arteries carry blood in opposite directions, allowing efficient transfer of metabolic heat in what is termed a "counter-current heat exchanger".



Like other sharks, the Great White has paired and unpaired fins. The pectoral and pelvic fins are paired, while the first dorsal, second dorsal, anal and tail fins are unpaired. The pectoral fins control banking, turning, ascending, descending and breaking. Plus, they act as signaling systems to other sharks. The first dorsal fin is important in preventing unwanted roll, keeping the shark level in the water. The caudal fin is the main propulsive structure, featuring an efficient crescentric shape and supported on either side by sturdy keels. All these fins allow the Great White to finely control its movement through the water. Especially when ascending and descending. Sensory structures
Vision



Sharks have developed methods of amplifying light in their eyes. They often depend heavily on eyesight when they come within short distances to any prey.
Sharks have excellent vision, in twilight hours even better than cats.



Scent



Sharks can smell certain substances 10,000 times better than humans, and can locate the smell of prey accurately over hundreds of meters. Once on a trail sharks will follow while swinging they’re head to make sure they always know in which direction to swim.



Taste



The decision on whether or not to eat a prey depends on how it tastes. Sharks have a very good sense of taste so it is not uncommon for a shark to ‘’taste test” any prey before consuming whole.

Electrosense
Probably the most interesting sensory structure