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Information about Zones Of The Lung

The zones of the lung proposed by West in 1964,[1] divide the lung into three vertical regions, based upon the relationship between the pressure in the alveoli (PA), in the arteries (Pa), and the veins (Pv):
  • #1: alveolar > arterial > venous
  • #2: arterial > alveolar > venous
  • #3: arterial > venous > alveolar
The ventilation/perfusion ratio is higher in zone #1 (the apex of lung when a person is standing) than it is in zone #3 (the base of lung.)

References

1. ^ West J, Dollery C, Naimark A. "Distribution of blood flow in isolated lung; relation to vascular and alveolar pressures". J Appl Physiol 19: 713-24. PMID 14195584. 

External links

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Respiratory system, physiology: respiratory physiology
Volumeslung volumes - vital capacity - functional residual capacity - respiratory minute volume - dead space - spirometry - body plethysmography - peak flow meter
Airwaysventilation (V) (positive pressure) - breath (inhalation, exhalation) -respiratory rate - respirometer - pulmonary surfactant - compliance - hysteresivity - airway resistance
Bloodpulmonary circulation - perfusion (Q) - hypoxic pulmonary vasoconstriction - pulmonary shunt
Interactionsventilation/perfusion ratio (V/Q) and scan - zones of the lung - gas exchange - pulmonary gas pressures - alveolar gas equation - hemoglobin - oxygen-haemoglobin dissociation curve (2,3-DPG, Bohr effect, Haldane effect) - carbonic anhydrase (chloride shift) - oxyhemoglobin - respiratory quotient - arterial blood gas - diffusion capacity - Dlco
Control of respirationpons (pneumotaxic center, apneustic center) - medulla (dorsal respiratory group, ventral respiratory group) - chemoreceptors (central, peripheral) - pulmonary stretch receptors - Hering-Breuer reflex
Insufficiencyhigh altitude - oxygen toxicity - hypoxia
lungs flank the heart and great vessels in the chest cavity.[1]]]

The lung is the essential respiration organ in air-breathing vertebrates, the most primitive being the lungfish.
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alveolus (plural: alveoli, from Latin alveus, "little cavity"), is an anatomical structure that has the form of a hollow cavity. Mainly found in the lung, the pulmonary alveoli
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Arteries are muscular blood vessels that carry blood away from the heart.[1] All arteries, with the exception of the pulmonary and umbilical arteries, carry oxygenated blood.

The circulatory system is extremely important for sustaining life.
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vein is a blood vessel that carries blood toward the heart. The majority of veins in the body carry low-oxygen blood from the tissues back to the heart; the exceptions being the pulmonary and umbilical veins which both carry oxygenated blood.
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In respiratory physiology, the ventilation/perfusion ratio (or V/Q ratio) is a measurement used to the efficiency and adequacy of the matching of two variables:[1]
  • "V" - ventilation - the air which reaches the lungs

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The apex of the lung is rounded, and extends into the root of the neck, reaching from 2.5 to 4 cm. above the level of the sternal end of the first rib.

A sulcus produced by the subclavian artery as it curves in front of the pleura runs upward and lateralward immediately
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The base of the lung is broad, concave, and rests upon the convex surface of the diaphragm, which separates the right lung from the right lobe of the liver, and the left lung from the left lobe of the liver, the stomach, and the spleen.
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Medical College of Georgia is the smallest of four research schools in the University System of Georgia (USG). MCG currently has 5 undergraduate and graduate schools on campus: The School of Medicine, School of Dentistry, School of Nursing, School of Allied Health, and Graduate
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respiratory system generally includes tubes, such as the bronchi, used to carry air to the lungs, where gas exchange takes place. A diaphragm pulls air in and pushes it out. Respiratory systems of various types are found in a wide variety of organisms.
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Human physiology is the science of the mechanical, physical, and biochemical functions of humans in good health, their organs, and the cells of which they are composed. The principal level of focus of physiology is at the level of organs and systems.
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Respiratory physiology is the branch of human physiology focusing upon respiration.

Topics include:

Volumes

  • lung volumes
  • vital capacity
  • functional residual capacity
  • dead space
  • spirometry
  • body plethysmography
  • peak flow meter


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Larger volumes Smaller volumes
males females
taller people shorter people
non-smokers heavy smokers
professional athletes[1] non-athletes
people living at high altitudes people living at low altitudes
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Vital capacity is the maximum volume of air that a person can exhale after maximum inhalation. It can also be the maximum volume of air that a person can inhale after maximum exhalation.
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Functional Residual Capacity (FRC) is the volume of air present in the lungs at the end of passive expiration. At FRC, the elastic recoil forces of the lungs and chest wall are equal but opposite and there is no exertion by the diaphragm or other respiratory muscles.
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Respiratory minute volume (or minute ventilation, or flow of gas) is the volume of air which can be inhaled (inhaled minute volume) or exhaled (exhaled minute volume) from a person's lungs in one minute.
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dead space is air that is inhaled by the body in breathing, but does not partake in gas exchange.

In adults, it is usually in the range of 150ml.[1]

Understanding dead space


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Spirometry (meaning the measuring of breath) is the most common of the Pulmonary Function Tests (PFTs), measuring lung function, specifically the measurement of the amount (volume) and/or speed (flow) of air that can be inhaled and exhaled.
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Please help [ improve the introduction] to meet Wikipedia's layout standards.

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A peak flow meter is a small, hand-held device used to manage asthma by monitoring airflow through the bronchi and thus the degree of restriction in the airways. The peak flow meter measures the patient's maximum ability to expel air from the lungs, or
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ventilation (or ventilation rate) is the rate at which gas enters or leaves the lung. It is categorised under the following definitions:

Measurement Equation Description
Minute ventilation = tidal volume * respiratory rate[1]
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Positive pressure ventilators help patients with respiratory problems to breathe easier. They use high pressure gas at the opening of the patients lungs in order to mobilize oxygen flow down the pressure gradient, and into the patient's lungs.
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Breathing transports oxygen into the body and carbon dioxide out of the body. Aerobic organisms require oxygen to create energy via respiration, in the form of energy-rich molecules such as glucose. The medical term for normal relaxed breathing is eupnoea.
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Inhalation (also known as inspiration) is the movement of air from the external environment, through the airways, into the alveoli during breathing.

Inhalation begins with the onset of contraction of the diaphragm, which results in expansion of the intrapleural space
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Exhalation (or expiration) is the movement of air out of the bronchial tubes, through the airways, to the external environment during breathing.

Exhaled air is rich in carbon dioxide, a waste product of cellular respiration during the production of ATP.
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respiratory rate (or respiration rate) is the number of breaths a living being, such as a human, takes per minute.

There is only limited research on monitoring alien respiratory rate, and these studies have focused on such issues as the inaccuracy of respiratory rate
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A respirometer is a device used to measure the rate of respiration of a living organism by measuring its rate of exchange of oxygen and carbon dioxide. They allow investigation into how factors such as age or the effect of light affect the rate of respiration.
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Pulmonary surfactant is a surface-active lipoprotein complex formed by type II alveolar cells. The proteins and lipids that comprise surfactant have both a hydrophilic region and a hydrophobic region.
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158 (4): 1052-60. PMID 9769260.
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“Hysteresivity” derives from “hysteresis”, meaning “lag”. It is the tendency to react slowly to an outside force, or to not return completely to its original state.
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Airway resistance is a concept used in respiratory physiology to describe mechanical factors which limit the access of inspired air to the pulmonary alveoli, and thus determine airflow.
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