Learn more about the fascinating functions of hydrodynamic mechanisms and hydraulics in nature.

Hypertension And Obturator Muscle Functions

Posted: December 14th, 2009 | Filed under: Extra unnatural functions | Tags: , , , , , , , | No Comments »

Nature is always striving to allot an organ certain extra unnatural functions. Although the duties of the cardiovascular system are very specific and highly responsible, it could not avoid this common plight since nature was eager to utilize the pressure in the circulation system.

Hypertension (abnormally high blood pressure) is known to be very dangerous for the organism as it may disturb the blood system and cause damage to the blood vessels. Nature, however, turned this phenomenon to advantage. Thus, the lizards, known as horned toads, inhabiting the deserts of Mexico, use the local hypertension in the blood vessels of the head as a means of defence.

Generally speaking, this phenomenon is not terribly uncommon. When the blood, under abnormally high pressure, enters the crests, spines, and other outgrowths on the head and the body, they expand, straighten out, change colour and make the animal look fearful.

This is not the only means of defence of horned toads. Nature supplied them with a wonderful mechanism: when the lizard is standing at bay, a specific muscle, known as the obturator muscle, presses against one of the major blood vessels, markedly raising the pressure in the blood vessels in the head; it proves too high for the delicate vessels in the nictitating membrane and they rupture squirting blood into the face of a predator. This unexpected shower often makes the intruder take flight. This weapon is operative within the radius of one and a half metres.

The other function of the obturator muscle is connected with moulting. The reptiles continue growing throughout their lives. Horned toads change their skin every year. Casting oil one’s clothes can sometimes be difficult. This is where the obturator muscle comes into play. When the pressure in the head vessels increases, all the blood vessels, major and minor, distend and the head expands, tearing the old skin. When the skin on the head has ruptured, the lizard simply crawls out of it through the newly formed opening.