|
|
|
World's Tallest's Headache !!!
 |
| Photo Information |
Copyright: Subhash Ranjan (sranjan)
(1176) |
| Genre: Animals |
| Medium: Color |
| Date Taken: 2008-01-24 |
| Categories: Mammals |
| Photo Version: Original Version |
| Date Submitted: 2008-07-07 9:30 |
| Viewed: 225 |
| Points: 10 |
|
| [Note Guidelines] Photographer's Note |
The giraffe heart is probably the most powerful in the animal kingdom, because about double normal pressure is required to pump blood up that long neck to the brain. But the brain is a very delicate structure which cannot stand high blood pressure. What happens when the giraffe bends down to take a drink? Does he ‘blow his mind’? Fortunately, three design features have been included in the giraffe to control this and related problems.
In the first place, the giraffe must spread his front legs apart in order to drink comfortably. This lowers the level of the heart somewhat and so reduces the difference in height from the heart to the head of the drinking animal. The result is that excess pressure in the brain is less than it would be if the legs were kept straight.
Second, the giraffe has in his jugular veins a series of one-way check valves which immediately close as the head is lowered, thus preventing blood from flowing back down into the brain.
But what of the blood flow through the carotid artery from the heart to the brain?
A third design feature is the ‘wonder net’, a spongy tissue filled with numerous small blood vessels located near the base of the brain. The arterial blood first flows through this net of vessels before it reaches the brain. It is believed that when the animal stoops to drink, the wonder net in some way controls the blood flow so that the full pressure is not exerted on the brain.
Scientists also believe that probably the cerebrospinal fluid which bathes the brain and spinal column produces a counter-pressure which prevents rupture or leakage from the brain capillaries. The effect is similar to that of a G-suit worn by fighter pilots and astronauts. The G-suit exerts pressure on the body and legs of the wearer under high acceleration and prevents blackout. Leakage from the capillaries in the giraffe’s legs, due to high blood pressure, is also probably prevented by a similar pressure of the tissue fluid outside the cells. In addition, the walls of the giraffe’s arteries are thicker than those in any other mammal.
Source:http://www.answersingenesis.org/creation/v14/i2/giraffes.asp |
parthasarathi, CeltickRanger has marked this note useful Only registered TrekNature members may rate photo notes. |
|
|
| Discussions |
| None | | You must be logged in to start a discussion. |
|
Nice shot. As you are a person from medical field your informations are more accurate.
Hi Subhas...Very good portrait ...Look pretty too....Information interesting......Excellent patten...Regards, Leyla
- lousat
(9197) - [2008-07-07 16:27]
-
Hi,just marking no time,excellent pic,be back tomorrow,Luciano
- arfer
(0) - [2008-07-08 8:00]
-
Hello Subhash
A lovely capture of this giraffe.
The details are good.
Very good pov and dof.
A lovely perspective.
TFS
Rob
Hello Subhash
excellent portrai shot of the Giraffe, with fine POV and DOF,
excellent sharpness and details of the subject,
also very educative notes, TFS
Asbed
Great Photo. Stunning. You have the most unique pictures.