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jus gimme a few lines......thxxxx.bibi

2007-01-28 22:58:10 · 6 answers · asked by Anonymous in Environment

6 answers

This web page should give you a very clear description :
http://en.wikipedia.org/wiki/Lung

2007-01-28 23:01:41 · answer #1 · answered by Indychen 6 · 8 0

The lungs are a pair of spongy, air-filled organs located on either side of the chest (thorax). The trachea (windpipe) conducts inhaled air into the lungs through its tubular branches, called bronchi. The bronchi then divide into smaller and smaller branches (bronchioles), finally becoming microscopic. The bronchioles eventually end in clusters of microscopic air sacs called alveoli. In the alveoli, oxygen from the air is absorbed into the blood. Carbon dioxide, a waste product of metabolism, travels from the blood to the alveoli, where it can be exhaled. Between the alveoli is a thin layer of cells called the interstitium, which contains blood vessels and cells that help support the alveoli. The lungs are covered by a thin tissue layer called the pleura. The same kind of thin tissue lines the inside of the chest cavity -- also called pleura. A thin layer of fluid acts as a lubricant allowing the lungs to slip smoothly as they expand and contract with each breath.

2016-03-15 01:43:18 · answer #2 · answered by ? 3 · 0 0

The lung is the essential respiration organ in air-breathing vertebrates. Its principal function is to transport oxygen from the atmosphere into the bloodstream, and to excrete carbon dioxide from the bloodstream into the atmosphere. This exchange of gases is accomplished in the mosaic of specialized cells that form millions of tiny, exceptionally thin-walled air sacs called alveoli. The lungs also have nonrespiratory functions.

Much more: http://en.wikipedia.org/wiki/Lungs

2007-01-28 23:01:36 · answer #3 · answered by Anonymous · 0 0

Lungs take in oxygen from air, expel CO2 and other gasses,oxygen from air is taken in by the tiny blood vessels in the lungs and is passed through your heart and pumped through out the rest of your bodies circulatory system where the oxygenated blood supplies energy for muscles and organs, back to your heart and lungs where blood is again oxygenated and and CO2 expelled and it starts all over again around and around
Also, plants give off O2 as a waste product which we need to live, we give off CO2 as waste which plants need to survive (just thought I'd throw that in
PS go to Wikipedia for a much better more complete answer, am sure my def is far from perfect, but I gave you what I could remember from school, hope helped, GL

2007-01-28 23:15:01 · answer #4 · answered by GreyGHost29 3 · 1 0

lungs are the essential respiration organ in air-breathing vertebrates. the function is to transport oxygen from the atmosphere to the bloodstream, also to excrete carbon dioxide from the bloodstream into the atmosphere. exchange of gases is accomplished in the mosaic of specialized cells that form millions of tiny, exceptionally thin-walled air sacs called alveoli.

2007-01-28 23:02:19 · answer #5 · answered by Anonymous · 0 0

"The substance of the lung is dilatable and extensible like the tinder made from a fungus. But it is spongy and if you press it, it yields to the force which compresses it, and if the force is removed, it increases again to its original size." -- Leonardo da Vinci, late 15th century

Early descriptions of the lungs emphasized their importance as cooling agents that maintained the balance of the human body by counteracting the hot temperament of the heart. They also understood that breathing occurred in the lungs, in essence, that the lungs acted like a pair of bellows firing and cooling a furnace. Galen's description, for example, of the lung emphasized that it "has all the properties which make for easy evacuation; for it is very soft and warm and is kept in constant motion." He further specified the function of the lungs in relationship to the movement of the blood as follows: "Blood passing through the lungs absorbed from the inhaled air, the quality of heat, which it then carried into the left heart." From such passages, we can see that the idea of respiration was primarily influenced by humoral theories of the body.

Medieval medical practitioners continued to be fascinated by the unusual anatomy of the lung. They noted its unusual moisture, for example, as a feature of its complexion. In the early eleventh century, the Islamic medical philosopher Avicenna wrote in his Canon of Medicine: "In the case of the lung the moisture is not inherent in its nature but is derived from the nourishment which comes to it. The lung is fed by a very 'hot' blood, because there is much bilious humor in the blood going to the lung. A great excess of moisture accumulates in the lung from the gaseous products of the whole body as well as from the materials which flow down to it from the "head." By the late twelfth century, Master Nicolaus summarized well the qualities of the lung: it was built to "withstand the warmth of the heart," its soft, spongy tissue facilitated motion, it was hollow in order to retain air "for cooling the heart and renewing the vital spirits," and it exhibited a twofold motion that further facilitated its role as "the flail of the heart."

Medieval and Renaissance physicians understood the connection between the lungs and respiration and between life and breath. They associated life with a vitality that coursed throughout the body, a Galenic pneuma. But they had no specific understanding of the role that oxygen played, since they had no chemical understanding of air which was one of the four basic "elements" of nature in traditional Greek science. Despite this fact, they did understand that the lung discharged wastes. Leonardo da Vinci describes the process as follows in his unpublished notebooks of the late fifteenth century: "From the heart, impurities or 'sooty vapors' are carried back to the lung by way of the pulmonary artery, to be exhaled to the outer air." His contemporary, the physician Alessandro Benedetti concurred, writing in 1497, "The lung changes the breath, as the liver changes the chyle, into food for the vital spirit."

Despite Leonardo's carefully drawn images of the anatomy of the lungs, as seen in the illustration here, he did not yet understand the relationship between form and function in any great detail. What he, like many early anatomists, had grasped was the lung's important role as an organ that worked cooperatively with closely allied organs and structures in the human body. What he understood, as the passage below suggests, is the mechanical process of breathing but not the actual mechanisms at work in creating a breath. "The gust of wind driven out of the lung in the generation of a large breath comes from the aid of the abdominal wall which compresses the intestines, and they elevate the diaphragm which compresses the lungs."

Renaissance anatomists stuck closely to a complexion theory of the lungs that also gave them a role in the psychology of the human body. Leonardo's contemporary, the physician Alessandro Benedetti, wrote in 1497 that the lungs controlled emotions such as anger by placating the passions " with the breath of the spirit from the hollow fistulae of the lungs. Thus anger, otherwise implacable, is easily calmed." Similarly, some anatomists endowed the lungs with powers of discernment that prevented them from accepting "bad air" into the human body. Just as the lungs could make "food" for the body, they could also prevent poisonous thoughts and substances from overwhelming it.

The more careful anatomical studies of the human body conducted by Renaissance anatomists yielded a more precise physical description of the lungs. Whereas Master Nicolaus had described the human lung as having seven lobes, early sixteenth-century anatomists reduced that number to five. They noted that the sponginess of the lungs facilitated breathing, though the nature of breathing was still described much as Galen had done: "so that they may more easily draw the spirit into themselves," was how Andreas de Laguna put it in 1535. Yet only a few decades later, we can begin to see emerging doubts about the kind of spirit flowing through the lungs. "This air is not a pure element but an airy body and thus can nourish," wrote Vesalius' contemporary Niccolo Massa in 1559, "although Galen, that great philosopher, thought he understood it in another sense, for air prepared in the lung itself nourishes or restores the spirit."

Writing from an entirely different philosophical tradition, the German mystic and medical reformer Paracelsus made the study of lung diseases at the beginning of the sixteenth century a case study in understanding how disease might be localized to a specific organ rather than a general imbalance of the body. In his On the Miner's Sickness, he identified lung-related ailments, especially silicosis, as a direct product of working in the mines. Such research further emphasized the importance of the lungs to the overall health of the body.

By the early seventeenth century, the new anatomy of the lung was in place. William Harvey concurred with his Renaissance predecessors on the five-lobe structure of the lungs. Yet he took their views several steps further in describing the significance of the lungs. Having already established a new physiology of the body in his On the Circulation of the Blood (1628), Harvey had a different understanding of the relationship between arteries and veins -- no longer separate circulatory systems within the body but a unified system. As a result, he had a question: what makes arterial blood different from venous blood? In his famous work, Harvey had described in great detail pulmonary transit in the lungs. As a result, he had the following to say about the lungs in his Lectures on the Whole of Anatomy (1653):

"Pre-eminence [of the lung]: nothing is especially so necessary neither sensation nor aliment. Life and respiration are complementary. There is nothing living which does not breathe nor anything which breathing which does not live."

This insight was followed by a strong critique of Galen, who had argued that the liver was the first and most important organ of the body. Harvey concluded the opposite: "The lungs make the spirits and indicate the nourishment wherefore more worthy than the liver if honor is judged by benefit." Instead he drew inspiration from Aristotle in arguing that spirit was not a product of air but of blood, and the lungs were therefore indicative of a person's temperament. Bold people have hot lungs, timid people have cold lungs. While creating a new physiology that gave greater importance to the lungs, Harvey was nonetheless deeply indebted to older traditions of thought. As a practicing physician, he also recognized that healthy lungs were essentially to the overall health of the body. In anticipation of more modern attitudes towards this organ, he wrote that exercise was important to the maintenance of this organ. He still, of course, had no idea about oxygen, nor even knew this word.

2007-01-28 23:10:20 · answer #6 · answered by venkey30 2 · 0 1

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