Thread: Lungs...???

What's the function?
What body parts are involved?
What can harm it?

How can people keep it healthy?

FUNCTION
Its the respiration organ that takes in oxygen from the air and relases it through our blood streams and gives out the CO2
PARTS INVOLVED
the respiration system
HARM
Smoking, diseases (cancer..)
people keep it healthy simple by breathing in clean fresh air!!!
hope this helped!

Respiratory function

Energy production to aerobic respiration requires oxygen and glucose and produces carbon dioxide as a waste product, creating a need for an efficient means of oxygen delivery to cells and excretion of carbon dioxide from cells. In small organisms, such as single-celled bacteria, this process of gas exchange can take place entirely by simple diffusion. In larger organisms, this is not possible; only a small proportion of cells are close enough to the surface for oxygen from the atmosphere to enter them through diffusion. Two major adaptations made it possible for organisms to attain great multicellularity: an efficient circulatory system that conveyed gases to and from the deepest tissues in the body, and a large, internalized respiratory system that centralized the task of obtaining oxygen from the atmosphere and bringing it into the body, whence it could rapidly be distributed to all the circulatory system.

In air-breathing vertebrates, respiration occurs in a series of steps. Air is brought into the animal via the airways — in reptiles, birds and mammals this often consists of the nose; the pharynx; the larynx; the trachea (also called the windpipe); the bronchi and bronchioles; and the terminal branches of the respiratory tree. The lungs of mammals are a rich lattice of alveoli, which provide an enormous surface area for gas exchange. A network of fine capillaries allows transport of blood over the surface of alveoli. Oxygen from the air inside the alveoli diffuses into the bloodstream, and carbon dioxide diffuses from the blood to the alveoli, both across thin alveolar membranes.

The drawing and expulsion of air is driven by muscular action; in early tetrapods, air was driven into the lungs by the pharyngeal muscles, whereas in reptiles, birds and mammals a more complicated musculoskeletal system is used. In the mammal, a large muscle, the diaphragm (in addition to the internal intercostal muscles) drives ventilation by periodically altering the intra-thoracic volume and pressure; by increasing volume and thus decreasing pressure, air flows into the airways down a pressure gradient, and by reducing volume and increasing pressure, the reverse occurs. During normal breathing, expiration is passive and no muscles are contracted (the diaphragm relaxes).

Another name for this inspiration and expulsion of air is ventilation. Vital capacity is the maximum volume of air that a person can exhale after maximum inhalation. A person's vital capacity can be measured by a spirometer (spirometry). In combination with other physiological measurements, the vital capacity can help make a diagnosis of underlying lung disease.

Non respiratory functions

In addition to respiratory functions such as gas exchange and regulation of hydrogen ion concentration, the lungs also:

* influence the concentration of biologically active substances and drugs used in medicine in arterial blood
* conversion of angiotensin I to angiotensin II by the action of angiotensin-converting enzyme
* filter out small blood clots formed in veins
* regulating pH of blood by regulating the bicarbonate buffering system and the partial pressure of carbon dioxide
* serve as a physical layer of soft, shock-absorbent protection for the heart, which the lungs flank and nearly enclose.
* filter out gas micro-bubbles occurring in the venous blood stream such as those created after SCUBA diving (decompression).
* The conducting zone contains the trachea, the bronchi, the bronchioles, and the terminal bronchioles
* The respiratory zone contains the respiratory bronchioles, the alveolar ducts, and the alveoli.

The conducting zone and the respiratory zone (but not the alveoli) are made up of airways.

The conducting zone has no gas exchange with the blood, and is reinforced with cartilage and smooth muscle, which are very strong. Smooth muscle has variable resistance to air flow. The conducting zone warms the air to 37 degrees Celsius and humidifies the air. It also cleanses the air by removing particles.

The respiratory zone is the site of gas exchange with blood.

The smooth muscle tone in bronchioles, and therefore bronchiolar diameter, is controlled by:

* the sympathetic nervous system via noradrenaline acting on the beta receptors and causes bronchodilation
* the parasympathetic nervous system via acetylcholine which acts on the muscarinic receptors and causes bronchoconstriction
* many other non-autonomic nervous and biochemical stimuli including, for example, carbon dioxide.

The intrapleural space is the potential space between the pleura lining the inner wall of the thoracic cage and the pleura lining the lungs.


* The conducting zone contains the trachea, the bronchi, the bronchioles, and the terminal bronchioles
* The respiratory zone contains the respiratory bronchioles, the alveolar ducts, and the alveoli.

The conducting zone and the respiratory zone (but not the alveoli) are made up of airways.

The conducting zone has no gas exchange with the blood, and is reinforced with cartilage and smooth muscle, which are very strong. Smooth muscle has variable resistance to air flow. The conducting zone warms the air to 37 degrees Celsius and humidifies the air. It also cleanses the air by removing particles.

The respiratory zone is the site of gas exchange with blood.

The smooth muscle tone in bronchioles, and therefore bronchiolar diameter, is controlled by:

* the sympathetic nervous system via noradrenaline acting on the beta receptors and causes bronchodilation
* the parasympathetic nervous system via acetylcholine which acts on the muscarinic receptors and causes bronchoconstriction
* many other non-autonomic nervous and biochemical stimuli including, for example, carbon dioxide.

The intrapleural space is the potential space between the pleura lining the inner wall of the thoracic cage and the pleura lining the lungs.
Diseases of the human lung belong to respiratory diseases. The following is a list of important medical conditions involving the lung. Many of these are caused or worsened by smoking.

* Lung cancer
* Emphysema is an enlargement of the air spaces in the lung, making it hard to breathe.
* Asthma is an immunological disease which causes the bronchioles to narrow by inflammation and spasm of the lining of the airway wall.
* Cystic fibrosis is a hereditary disease which causes the lung to produce abnormally viscous mucus.
* A pulmonary embolism occurs when a blood clot obstructs an artery leading to the lung.
* Tuberculosis is a transmittable bacterial infection of the lung, the most common infectious disease today.
* Pneumonia is an infection of the lung, caused by bacteria, viruses or fungi.
* Pneumoconiosis, an occupational lung disease caused by the inhalation of dust.
* Bronchitis is an inflammation of the bronchi.
* A collapsed lung (pneumothorax) can occur when one or both walls of the pleural cavity are penetrated by injury, allowing air to enter.
* In pulmonary edema fluid from the capillaries enters the alveoli. This can be caused by weakness of the left side of the heart (resulting in a blood holdup in the lung), altitude sickness, or rarely inhaling toxic gases.
* Lung pinprick condition is a hereditary disease which results in decreased lung capacity and occasional shortness of breath.

Transplantation now allows for a person to have a single lung transplant, a double-lung transplant, or a transplant of both the heart and lungs.
Total lung capacity (TLC) includes inspiratory reserve volume, tidal volume, expiratory reserve volume, and residual volume.[2] The total lung capacity depends on the person's age, height, weight, sex, and normally ranges between 4,000 and 6,000 cm3 (4 to 6 L). For example, females tend to have a 20–25% lower capacity than males. Tall people tend to have a larger total lung capacity than shorter people. Smokers have a lower capacity than nonsmokers. Lung capacity is also affected by altitude. People who are born and live at sea level will have a smaller lung capacity than people who spend their lives at a high altitude. In addition to the total lung capacity, one also measures the tidal volume, the volume breathed in with an average breath, about 500 cm3. For a detailed discussion of the various lung volumes, see the article on lung volumes.[3]


Typical resting adult respiratory rates are 10–20 breaths per minute with 1/3 of the breath time in inspiration.

Human lungs are to a certain extent 'overbuilt' and have a tremendous reserve volume as compared to the oxygen exchange requirements when at rest. This is the reason that individuals can smoke for years without having a noticeable decrease in lung function while still or moving slowly; in situations like these only a small portion of the lungs are actually perfused with blood for gas exchange. As oxygen requirements increase due to exercise, a greater volume of the lungs is perfused, allowing the body to reach its CO2/O2 exchange requirements.

Lungs is basically for breathing and purifying the air which you breath.... all parts depends upon it's operation.... the things like smoking, regular exposure to smoke will lead to failure.... be away from peoples who smoke.. don't smoke....