Hydrotour - The dromedary

True miracle on legs, the dromedary surprises, astonishes but cannot leave indifferent. It has the stupid air, it is not very accessible and especially, it flees the caresses, which makes it rather antipathetic (it makes some is very câlin, but does not like the unknown ones). And they all are there criticisms which one can make him. Large, slim, majestic when it is in its environment, it impresses by its step, its ceaseless work which it carries out without seeming to notice that it makes more 40°C around him.
We saw it in transport of tourist and we gallopped on his back in Jordan with Petra, we saw it into large méharée going up the Nile, we saw it being rolled in sand, to drink 100 Liters of water in a few minutes, to wait the sun. In short from Syria the dromedary accompanies us in our voyage, it became an element of the decoration which we will miss thereafter.

Not to forget it and especially for its admirable management of water, we present this mythical animal below to you.
Called Camelus dromadarius by the scientists, it was introduced domesticated in Africa 5000 years ago by the south of the Arabic peninsula. 80% of the 20 million listed in the world live on the African ground, precisely in the most desert zones (Somalia, Sudan, Ethiopia...). The heat strength of the dromedary is proverbial. Whereas 15 to 30% of the goats and sheep and 20 to 50 % of the bovines die in the event of strong dryness, 95% of the dromedaries survive.

The dromedary developed a whole arsenal of combat to live in the desert:

An internal thermostat : By strong heat It raises its temperature up to 42 °C. What to differ its perspiration and the hydrous losses which result from it. Conversely it can lower its temperature to 30 °C to coldest of the night because it can make -10°C in the desert.
A stomach with any test : This ruminant is able to digest plastic and copper! Its stomach with 4 pockets stores up to 50 kilos of food and 136 liters of water (in the cells of the walls). As all the ruminants the stomach contains bacteria but it has the characteristic to have digestive glands.
An insulating fur : Doubled of under hairs, it enables him to resist the extreme climates (fur of 2,5kg). His/her cousin, the camel (Camelus bactrianus), thus tolerates temperatures from + 50 °C with - 50°C!
A bump pantry : While drawing from this reserve of grease, the dromedary manages to survive 3 weeks of jeun. Its bump to him provided energy and water drawn from the transformation of grease. In extreme situations, the man can carry out an incision and take grease to nourish himself. Well recousu the dromedary generally goes back from there without problem.
Tight eyelids : Furnished with the 2 lines of lashes in the shape of comb, they are closed again instantaneously in the event of danger and preserves the eyes of the least sand grain.
A nasal mucus cooling : This natural lubricant is thicker than that of the human nose. It humidifies the inhaled air, limiting the steam losses. Recovered water goes down in the mouth by the central furrow.
Utra-resistant lips : As firm as rubber, they graze without damage the bushes of thorn-bush. Distinctive mark of camélidés, a furrow splits the upper lip.
Air filters : Indeed in naseaux and the ears, a long barrier of hair, prevents sand and dust to penetrate in the conduits.
A purifier in the liver : This body decreases the liquid rejections by recycling urea (being able to be mortal in the event of excess in blood) in the form of water and of proteins.


	Caution, Dromedary! it changes us dry land...		The young Bedouin who is at the wheel of Adrienne rented his dromedary for a turn of ruin in the Oasis of Palmyre in Syria.

	The engine of our car is air cooled. There was thus no radiator containing of water.... a little as the dromedary which almost does not perspire.		These camel drivers lead a whole herd of dromedaries of Sudan towards Egypt while going along the Nile To Egypt the dromedary is very appreciated for its meat.

	In a few minutes the dromedary reloads and absorbs 100L water, these dromedaries are high for their meat.		Blocked kind the dromedary hardly can far away from the place where its camel driver put there. In full sun, it is put vis-a-vis at the sun to limit the impact of it.

Some technical details :

Recovery of the steam
In heat, the camel halète not and its rate of respiration is slowed down between 8 and 16 movements per minute. It thus exhales little steam. Moreover, it contracts the muscles of its nostrils to cool the steam nevertheless expired. Water resulting from this condensation is reabsorbed by the nasal mucous membrane.
The air which enters at the time of the inspiration undergoes the same treatment and, when the steam condenses in front of its naseaux, the water droplets made up are guided to the mouth by the furrows of the upper lip.

A recycling of water !
The water which circulates in the intestine and the kidneys is partly reabsorbed thanks to the combined action of two hormones released in greater quantity: the aldosterone and the ADH, antidiuretic hormone.
The reduction of blood volume for lack of water, stimulates the secretion of ADH which supports, on the level of the intestine, the reabsorption of water coming from the gastric juices and food. The saddles are thus almost dry. This hormone increases the cellular permeability and also acts on the kidneys to support the reabsorption of the water of the urine, from the urinary tubes towards blood. The quantity of urine is also to the minimum reduced.
Vegetable food bringing proteins little, contrary to a flesh-colored food, the liver has few amino acids in excess to degrade out of urea and acid uric. The urine, charged to disencumber blood of these highly toxic substances, can thus be very concentrated in the camel.
At the same time, the quantity of sodium decreases in blood and water is not fixed in fabrics. The blood pressure decreasing, the aldosterone is released to support the sodium retention on the level of the kidneys and, consequently, the water fixing in the body.

Renewal of water
When the requirements out of water strictly necessary are not brought by water and food (in the desert for example), camélidé drains water present in plasma, the interstitial lymph then the cellular cytoplasm, but also on that which comes from chemical reactions of the decomposition of greases of the bump: it is metabolic water (work of Knut and Bodil Schmidt-Nielsen).

A blessed bump
In the dromedary, grease in fact is accumulated in only one point for the period when food is abundant. It forms this famous bump which can weigh up to 14 kg.
It is an energy reserve which the camel burns in the absence of green food. This chemical reaction brings a small quantity to him, but how much invaluable, of metabolic water: each kilo of grease consumed brings 2 liters of metabolic water.
The decomposition of grease produces hydrogen which combines with dioxygene absorptive by inspiration to form water.
By combining this metabolic water with water present in the cells, the interstitial lymph and plasma, the camel can behave normally for a long period, even while working. If the fast is prolonged about fifteen days, the bump becomes soft, narrows, can melt of half and, so too much grease left, the splendid bump becomes a small cluster which hangs sadly on the side of the back of the camel. In an old camel, the bump being low in grease, the extreme conditions are badly supported. Over one lifespan 50 years, the camel thus takes its retirement at 25 years.
The chamelle one uses also water to manufacture milk after the birth, in wet period, of small or twins, after 12 months of gestation. The milk which it produces is rich in potassium which takes part in the retention of water in fabrics, so that a nomad needs only 2 to 4 liters of this invaluable beverage instead of 12 liters of water per day. Milk contains also little grease and lactose but much iron and vitamin C. The chamelle one produces some even in period of dryness whereas the other species (goats, ewe and others) stop producing some.