Invented the hourglass. Hourglass figure type: how to emphasize natural grace. Skirts for X-line
For athletes, especially swimmers, it is much higher - up to 6-7 liters. However, even after the deepest exhalation, another 1-1.5 liters of so-called residual air remain in the lungs. Even in a corpse, this air remains in the lungs, which is what causes the low specific gravity this organ. That is why the name “lungs” arose. If a person has taken at least one breath in his life, the residual air takes its place, and a piece of lung thrown into the water floats up. This is important in forensic medicine, because it allows you to determine whether the child was stillborn or died after birth.
During normal quiet breathing, a person inhales 500 ml of air. However, only about 350 ml reaches the alveoli. The remaining 150 ml of air fills the airways. This means that only 1/7 of the 3 liters of air contained in the lungs is renewed. In other words, the alveolar air is only diluted with fresh air, and not completely renewed. This makes sense: the blood flowing to the alveoli always comes into contact with air of approximately the same composition.
With 16 breaths per minute, a person makes more than 23 thousand respiratory movements per day, and over 7 thousand liters of air pass through the lungs. Muscle work causes increased and deepening of breathing. If at rest pulmonary ventilation per minute is 5-6 liters, then in well-trained athletes it can reach 140 liters when running at medium distances, i.e. it increases more than 5 times more than the minute volume of blood circulation.
The volume of air inhaled (exhaled) by a person
The amount of air consumed by an adult and a child when inhaling (exhaling)
Only when very strong physical activity we are able to increase the inhaled (exhaled) volume of air four times (i.e., up to 2/3 of three liters), thus obtaining two-thirds of the normal lung volume (2 liters - vital capacity of the lungs - vital capacity). In the same way, with a strong exhalation, a person can exhale an additional 1.5 liters of half a liter - the reserve volume. The maximum volume or total capacity of the lungs may exceed 3 liters. For some it reaches 5 or more liters (for example, trained athletes, athletes, etc.).
Minute and daily volume, taking into account different physical states of the body
So how much air does a person inhale and exhale per day? On average, we pass through our lungs 15 - 20 cubic meters air per day, and per year - approximately 6,000 cubic meters. meters. For the most long life a person is not able to use half a cubic kilometer of inhaled air.
Calculation of human need for fresh air
Diary entry created by Andrey-AA, 09/12/10
However. These data are taken for the case of carbon dioxide carryover from humans, i.e. as if in the fresh air, and therefore these figures have nothing to do with calculations for ventilation of premises.
I came up with an approach that will help determine the ventilation needs of homes, because I don’t trust SNiPs and sellers of happiness.
Briefly: oxygen is a useful gas, CO2 is harmful. It is necessary to determine for each of them, calculate the need for ventilation (cubic meters of air per hour per person), and then select the maximum figure from the two. This will be a reasonable figure for air exchange in homes.
I found this method in this article:
“If you do a little calculation, you find out the following.
For example, in a room of 33 m3, there are 10 people. 10 people exhale approximately (10X25) 250 liters of carbon dioxide per hour. As a result, the level of carbon dioxide will double in 21 minutes, and the level of oxygen will drop by a fraction of a percent over the same period of time."
"In our country, research on the effect of carbon dioxide on humans was carried out back in the 60s. O.V. Eliseeva, who used the methods of pneumography, rheovasography and electroencephalography, in the article “On the justification of the maximum permissible concentration of carbon dioxide in the air” in the journal Hygiene and Sanitation . – 1964. – No. 8., came to the following conclusions:
- Short-term inhalation of carbon dioxide in concentrations of 0.5 and 0.1% by healthy people causes distinct changes in the function of external respiration, blood circulation and electrical activity of the brain.
- Changes in these functions are more pronounced under the influence of CO2 at a concentration of 0.5%.
- The data obtained allow us to conclude that the concentration of CO2 in the air of residential and public buildings should not exceed 0.1% regardless of the source, and the average CO2 content should not exceed 0.05%."
If you believe this article, then on average a person exhales 25 liters of CO2 per hour, and its concentration should not exceed 0.1% (in nature - 0.04%). At rest - 15 liters of CO2 per hour.
Let's assume that in a dream - 10 liters of CO2 per hour, and in an active state - 30 liters / hour (small, domestic activity).
Let's try to figure out from here the need for ventilation while sleeping indoors.
Let's assume we have a sealed room - 20 square meters. meters (= 50 cubic meters). If, for example, it is well ventilated before going to bed, the CO2 concentration will be 0.04%. After 8 hours of sleep, a person will exhale 0.08 cubic meters of CO2, which is 0.16%, and in the morning there will be 0.2% CO2 (0.16% + 0.04%), which exceeds valid value 2 times, but presumably not fatal.
That is, during sleep, air exchange should be no less than 50/8 = 6.25 cubic meters per hour. And for healthy sleep - approximately 15 cubic meters per hour.
Let's determine the need for CO2 ventilation during wakefulness (exhalation - 30 liters of CO2 per hour).
With a room volume of 50 m3, an hour of breathing will add 0.06% to the CO2 concentration. In total with the initial concentration (0.04% + 0.06%) - 0.1%. Those. fresh air It's only enough for an hour.
Thus (in terms of CO2), air exchange during active home activity should be 50 cubic meters per hour per person (with a maximum CO2 content of 0.1%, since the average “hospital” value is not suitable here).
You probably need to look for and buy a CO2 meter and slowly figure out what’s going on in the apartment and at the dacha.
For example, Smart-2C02 (thanks for the tip - Master Master). A little expensive, really.
Found and added later:
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- How many liters of oxygen does a person consume per day?
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The amount of oxygen consumed by a person
If a person stands under the stream of a cold or fairly cool shower, the amount of oxygen he consumes will increase by almost 100%, and the release of carbon dioxide will increase by 150% (compared to conditions with room temperature air). Consequently, the increase in the frequency of respiratory processes is influenced by an increase in human heat loss.
Human lung capacity
The capacity of a person’s lungs is significantly influenced by the activity of his respiratory processes. The lung capacity of athletes exceeds the norm by 1-1.5 liters, and the lung capacity of professional swimmers can reach 6 liters. Accordingly, an increase in lung capacity reduces the respiratory rate and increases the depth of inspiration.
How long will one cubic meter of air last for a person?
How long will 1 m³ of air last for an adult without dying or suffocating?
The time for which one cubic meter of air is enough for a person depends on many factors, in particular:
- air temperature and humidity. If the air is colder, it contains more oxygen;
- on the physical parameters of a person. All people are different, and therefore have different lung volumes;
- frequency of breaths. The less you inhale, the more long time enough air;
- physical condition of a person. Most ideal option- this means lying quietly and not moving;
- emotional and psychological state of a person. In a state of calm, air consumption will be less.
On average, a person inhales liters of air per minute. If you calculate the maximum, that is, 10 liters of air per minute, then 1000 liters will be enough for 100 minutes. It should also be taken into account that the exhaled air contains carbon dioxide, therefore, we count the amount of air inhaled to the maximum.
There is an interesting film on the topic of the issue called “Buried Alive”.
By the way, when I read the question I immediately remembered the famous song “Breathing”:
One cubic meter of air can last indefinitely if you install an air regeneration unit.
Or another option is possible: pump into a container with a volume of one cubic meter compressed air With to a large extent compression and using it autonomously will also last for a long time. And if you also limit physical activity, the need for oxygen will decrease significantly.
In any case, the “survival time” under such conditions will increase significantly.
So it is simply impossible to say specifically that such and such an amount of air will be enough for such and such an amount of time, unless certain conditions of use are highlighted.
if you focus on normal life and focus on existing regulatory documents RF, then one person needs 60 m3/h (without the possibility of natural ventilation) - THEN 1 m3 is enough for one minute.
If a person plays sports (80m3/h), then less than a minute is 40 seconds.
But people are different in weight and therefore this is an average norm.
A person needs not air but oxygen; the air may initially contain a large percentage of carbon dioxide; such air will last for less time than air with a low carbon dioxide content. On average, a person needs 360 l/day for life, that’s 0.36 cubic meters, but I don’t think it’s 1 cubic meter in a confined space. enough for 2 days, perhaps a maximum of a day, since with each breath the amount of oxygen will decrease and carbon dioxide will increase
it all depends on the volume of a person’s lungs and how often he inhales air, that is, on the characteristics of his body and also on the state in which the person is in motion or at rest - on average, about 1 to 2 hours
..how many liters of air does a person need per day?
Also, the norms for shelters (without ventilation, i.e., boxes) are 2 cubic meters per person per hour per day.
So, if I understood your question correctly, then 8.6-16.0 cubic meters will be pumped through a person’s lungs per day. m of air (if it was not plowed).
If a person sits in an unventilated room, then this is a completely different problem, also easily solved. In its standard form, the formula for people staying in a closed chamber without ventilation usually determines the time they can sit there, and has the following form:
T=[(V-0.08*n)*(Kd-K)]:M*n (oh, it’s awkward to write formulas in mail) . Here T is the permissible time of stay in the chamber, hour. , V - volume of the chamber, l, n - number of people in the chamber, Kd - permissible concentration of carbon dioxide, l/l, K - initial concentration of carbon dioxide before closing the chamber, l/l, M - average release of carbon dioxide by one person in the chamber , l/hour. Since we are faced with another task - to determine the required volume of the chamber for a known time spent in it, we will transform this formula and obtain:
You wrote that the required time is one day, which means T=24; The release of carbon dioxide, if a person sits there for a day and is not preparing for a boxing match for the world champion title, I think can be taken as the daily average, that is, 30 l/hour (if more, substitute the necessary one; less is unlikely). Kd, that is, the permissible concentration of carbon dioxide. There is a lot of room for imagination here. Who is sitting - young healthy people or sickly and frail people? Children? Old people? In general, if the regime is gentle, then this value cannot be increased above 0.5%, and if young healthy people who can tolerate a possible mild headache jokingly, then nothing terrible will happen even at 1% per day. Yes, by the way, you write about hypoxia, so this is precisely the lack of oxygen, oxygen starvation. We calculate using carbon dioxide, so a possible unpleasant condition will be called hypercopnia, that is, excess CO2.
So, we take Kd in the range of 0.005-0.01, that is, from half a percent to one percent. Well, K knows that if the air is not polluted, then it is 0.03%, that is, 0.0003.
If we substitute and round, we will end up with the required volume of the chamber for one person in dodoliters, or from 72 to 144 cubic meters. The difference, naturally, comes from the fact that permissible concentration we considered it to be within 0.5-1%. In a volume of 72 cubic meters per day, one organism will inhale approximately up to one percent, up to half a percent.
In general, I want to say that it is better to carry out such experiments with gas analyzers for oxygen and carbon dioxide in the chamber. If it is difficult to get equipment, you can at least buy glass tubes for express analysis and do it every hour. The fact is that sometimes you come across individual individuals who consume oxygen (and, accordingly, release carbon dioxide) in very large quantities. For example, we have one of these (I work on the Mir submersibles), its gas exchange is approximately two times higher than that of normal people. Further, smoking is strictly forbidden in this volume, and if you imprison a smoker, it is better for him to abstain from smoking for a day, otherwise he will inhale carbon monoxide, and this is worse than CO2. Well, the best thing, of course, is to organize some kind of simple life support system in a closed space. Then even if you sat in three cubic meters for a week, you would have something to drink and eat.
How much does the air we breathe in a day weigh?
Is it true that the air you breathe in is heavier than the food you eat during the day?
No matter how surprising and supernatural such a statement may sound, it is true. On average, a person eats no more than 3 kilograms of solid and liquid food per day, if it is weighed. Calculating the weight of inhaled air is also not difficult.
And so we calculate how many liters of air a person inhales per day. In one minute, you and I take about 15 breaths.
At the same time, each of our breaths introduces almost 0.5 liters of air into the lungs. Thus, a person inhales approximately liters of air per day! At standard pressure, such a volume of air will weigh about 14 kilograms, which is more than 4 times more than the food we eat per day. Did you think that air weighs nothing?
2 thoughts on “How much does the air we breathe in a day weigh”
Angle of incidence equal to angle reflections, if you are so smart, remove the dust that has settled in your lungs and get the answer.
How much air do we inhale?
The vital capacity of the lungs is about 3 liters. Do we really breathe in and out so much air every time?
If you take the deepest possible breath, and then exhale as completely as possible, then 3 or even 4 liters of air will come out of your lungs. This is an indicator of the vital capacity of your lungs. Athletes with a trained respiratory system (especially swimmers) have an even larger lung capacity. They can hold up to 6-7 liters of air. But in a normal situation - not in one breath.
During quiet breathing, any person inhales about 500 ml of air. Approximately 150 ml fills the airways. This means that no more than 350 ml reaches the lungs. And in one exhalation you remove approximately the same amount of waste air from them.
Divide your vital capacity (3 L, or 3000 ml) by 350 ml.
It turns out that you renew the entire volume of air contained in the lungs in 8 inhalations and exhalations.
Research methods and indicators of external respiration
Methods for studying functions and indicators of external respiration
The entire complex process of breathing can be divided into three main stages: external breathing; transport of gases by blood and internal (tissue) respiration.
External respiration is the exchange of gases between the body and the surrounding atmospheric air. External respiration involves the exchange of gases between atmospheric and alveolar air, as well as gas exchange between the blood of the pulmonary capillaries and the alveolar air.
This breathing occurs as a result of periodic changes in the volume of the chest cavity. An increase in its volume provides inhalation (inspiration), a decrease - exhalation (expiration). The phases of inhalation and subsequent exhalation constitute the respiratory cycle. During inhalation, atmospheric air enters the lungs through the airways, and when exhaling, some of the air leaves them.
Conditions necessary for external respiration:
- chest tightness;
- free communication of the lungs with the surrounding external environment;
- elasticity of lung tissue.
An adult takes breaths per minute. The breathing of physically trained people is rarer (up to 8-12 breaths per minute) and deeper.
The most common methods for studying external respiration
Methods for assessing respiratory function of the lungs:
- Pneumography
- Spirometry
- Spirography
- Pneumotachometry
- Radiography
- X-ray computed tomography
- Ultrasound examination
- Magnetic resonance imaging
- Bronchography
- Bronchoscopy
- Radionuclide methods
- Gas dilution method
Spirometry is a method of measuring the volume of exhaled air using a spirometer device. Spirometers are used different types with a turbimetric sensor, as well as water ones, in which exhaled air is collected under a spirometer bell placed in water. The volume of exhaled air is determined by the rise of the bell. IN lately Sensors sensitive to changes in volumetric air flow velocity connected to a computer system are widely used. In particular, this principle works computer system type "Spirometer MAS-1" Belarusian production etc. Such systems allow performing not only spirometry, but also spirography, as well as pneumotachography).
Spirography is a method of continuous recording of the volumes of inhaled and exhaled air. The resulting graphical curve is called spirophamma. Using a spirogram, you can determine the vital capacity of the lungs and tidal volumes, respiratory rate and voluntary maximum ventilation of the lungs.
Pneumotachography is a method of continuous recording of the volumetric flow rate of inhaled and exhaled air.
There are many other methods for studying the respiratory system. Among them are plethysmography of the chest, listening to the sounds that occur when air passes through the respiratory tract and lungs, fluoroscopy and radiography, determination of the oxygen and carbon dioxide content in the exhaled air flow, etc. Some of these methods are discussed below.
Volume indicators of external respiration
The relationship between lung volumes and capacities is presented in Fig. 1.
When studying external respiration, the following indicators and their abbreviations are used.
Total lung capacity (TLC) is the volume of air in the lungs after the deepest possible inspiration (4-9 l).
Rice. 1. Average values of lung volumes and capacities
Vital capacity of the lungs
Vital capacity (VC) is the volume of air that a person can exhale with the deepest, slow exhalation made after a maximum inhalation.
The vital capacity of the human lungs is 3-6 liters. Recently, due to the introduction of pneumotachographic technology, the so-called forced vital capacity (FVC) is increasingly being determined. When determining FVC, the subject must, after inhaling as deeply as possible, make the deepest forced exhalation possible. In this case, exhalation should be made with an effort aimed at achieving the maximum volumetric speed of the exhaled air flow throughout the entire exhalation. Computer analysis of such forced exhalation makes it possible to calculate dozens of indicators of external respiration.
The individual normal value of vital capacity is called proper vital capacity (VLC). It is calculated in liters using formulas and tables based on height, body weight, age and gender. For women of one year old, the calculation can be made using the formula
JEL = 3.8*P + 0.029*B - 3.190; for men of the same age
JEL = 5.8*P + 0.085*B - 6.908, where P is height; B - age (years).
The value of the measured VC is considered reduced if this decrease is more than 20% of the VC level.
If the name “capacity” is used for the indicator of external respiration, this means that the composition of such a capacity includes smaller units called volumes. For example, TLC consists of four volumes, vital capacity - of three volumes.
Tidal volume (TV) is the volume of air entering and leaving the lungs in one respiratory cycle. This indicator is also called the depth of breathing. At rest in an adult, BC is ml (15-20% of the value of vital capacity); one month old baby - 30 ml; one year old - 70 ml; ten year old - 230 ml. If the depth of breathing is greater than normal, then such breathing is called hyperpnea - excessive, deep breathing, but if the depth of breathing is less than normal, then breathing is called oligopnea - insufficient, shallow breathing. With normal depth and frequency of breathing, it is called eupnea - normal, sufficient breathing. The normal resting respiratory rate in adults is 8–20 breaths per minute; a month-old baby - about 50; one-year-old - 35; ten years - 20 cycles per minute.
Inspiratory reserve volume (IR inspiratory volume) is the volume of air that a person can inhale with the deepest possible breath taken after a quiet breath. The normal PO value is 50-60% of the VC value (2-3 l).
Expiratory reserve volume (ER exhalation) is the volume of air that a person can exhale with the deepest exhalation made after a quiet exhalation. Normally, the RO value is 20-35% of vital capacity (1-1.5 l).
Residual lung volume (RLV) is the air remaining in the airways and lungs after maximum deep exhalation. Its value is 1-1.5 l (20-30% of TEL). In old age, the value of TRL increases due to a decrease in the elastic traction of the lungs, bronchial patency, a decrease in the strength of the respiratory muscles and the mobility of the chest. At the age of 60 years, it is already about 45% of the TEL.
Functional residual capacity (FRC) is the air remaining in the lungs after a quiet exhalation. This capacity consists of residual lung volume (RLV) and expiratory reserve volume (ER ext).
Not all atmospheric air entering the respiratory system during inhalation takes part in gas exchange, but only that which reaches the alveoli, which have a sufficient level of blood flow in the capillaries surrounding them. In this regard, so-called dead space is identified.
Anatomical dead space (ADS) is the volume of air located in the respiratory tract up to the level of the respiratory bronchioles (these bronchioles already have alveoli and gas exchange is possible). The amount of AMP is ml and depends on the characteristics of the human constitution (when solving problems in which it is necessary to take into account AMP, but its value is not indicated, the volume of AMP is taken equal to 150 ml).
Physiological dead space (PDS) is the volume of air entering the respiratory tract and lungs and not participating in gas exchange. FMP is larger than anatomical dead space, since it includes both component. In addition to the air in the respiratory tract, the FMF includes air that enters the pulmonary alveoli, but does not exchange gases with the blood due to the absence or reduction of blood flow in these alveoli (the name alveolar dead space is sometimes used for this air). Normally, the value of functional dead space is 20-35% of the tidal volume. An increase in this value above 35% may indicate the presence of certain diseases.
Table 1. Indicators of pulmonary ventilation
In medical practice, it is important to take into account the dead space factor when designing breathing devices (high-altitude flights, scuba diving, gas masks), conducting a number of diagnostic and resuscitation measures. When breathing through tubes, masks, hoses, additional dead space is connected to the human respiratory system and, despite the increase in the depth of breathing, ventilation of the alveoli with atmospheric air may become insufficient.
Minute breathing volume
Minute respiration volume (MVR) is the volume of air ventilated through the lungs and respiratory tract in 1 minute. To determine the MOR, it is enough to know the depth, or tidal volume (TV), and respiratory frequency (RR):
In mowing, MOD is 4-6 l/min. This indicator is often also called pulmonary ventilation (distinguished from alveolar ventilation).
Alveolar ventilation
Alveolar ventilation (AVL) is the volume of atmospheric air passing through the pulmonary alveoli in 1 minute. To calculate alveolar ventilation, you need to know the value of the AMP. If it is not determined experimentally, then for calculation the volume of AMP is taken equal to 150 ml. To calculate alveolar ventilation, you can use the formula
For example, if a person’s breathing depth is 650 ml and the respiratory rate is 12, then AVL is equal to 6000 ml () 12.
- AB - alveolar ventilation;
- DO alve - tidal volume of alveolar ventilation;
- RR - respiratory rate
Maximum pulmonary ventilation (MVL) is the maximum volume of air that can be ventilated through a person’s lungs in 1 minute. MVL can be determined by voluntary hyperventilation at rest (breathing as deeply as possible and often at a slant is permissible for no more than 15 seconds). With the help of special equipment, MVL can be determined while a person is performing intense physical work. Depending on the constitution and age of a person, the MVL norm is within the range of hl/min. In athletes, MVL can reach 200 l/min.
Flow indicators of external respiration
In addition to lung volumes and capacities for assessing the condition respiratory system use the so-called flow indicators of external respiration. The simplest method for determining one of them - peak expiratory volumetric flow rate - is peak flowmetry. Peak flow meters are simple and quite affordable devices for use at home.
Peak expiratory volume flow (PEF) is the maximum volumetric flow rate of exhaled air achieved during forced exhalation.
Using a pneumotachometer device, you can determine not only the peak volumetric flow rate of exhalation, but also inhalation.
In a medical hospital, pneumotachograph devices with computer processing of the received information are becoming increasingly common. Devices similar type allow, based on continuous recording of the volumetric velocity of the air flow created during exhalation of the forced vital capacity of the lungs, to calculate dozens of indicators of external respiration. Most often, POS and maximum (instantaneous) volumetric air flow rates at the moment of exhalation are determined as 25, 50, 75% FVC. They are called respectively indicators MOS 25, MOS 50, MOS 75. The definition of FVC 1 is also popular - the volume of forced expiration for a time equal to 1 e. Based on this indicator, the index (indicator) Tiffno is calculated - the ratio of FVC 1 to FVC expressed as a percentage. A curve is also recorded that reflects the change in the volumetric velocity of the air flow during forced exhalation (Fig. 2.4). In this case, the volumetric velocity (l/s) is displayed on the vertical axis, and the percentage of exhaled FVC is displayed on the horizontal axis.
In the graph shown (Fig. 2, upper curve), the vertex indicates the value of PVC, the projection of the moment of exhalation of 25% FVC on the curve characterizes MVC 25, the projection of 50% and 75% FVC corresponds to the values of MVC 50 and MVC 75. Not only flow velocities at individual points, but also the entire course of the curve are of diagnostic significance. Its part, corresponding to 0-25% of exhaled FVC, reflects the air patency of the large bronchi, trachea and upper respiratory tract, the area from 50 to 85% of FVC - the patency of small bronchi and bronchioles. A deflection in the descending section of the lower curve in the expiratory region of 75-85% FVC indicates a decrease in the patency of the small bronchi and bronchioles.
Rice. 2. Stream breathing indicators. Note curves - volume healthy person(upper), a patient with obstructive obstruction of the small bronchi (lower)
Determination of the listed volume and flow indicators is used in diagnosing the state of the external respiration system. To characterize the function of external respiration in the clinic, four variants of conclusions are used: normal, obstructive disorders, restrictive disorders, mixed disorders (a combination of obstructive and restrictive disorders).
For most flow and volume indicators of external respiration, deviations of their value from the proper (calculated) value by more than 20% are considered to be outside the norm.
Obstructive disorders are disturbances in the patency of the airways, leading to an increase in their aerodynamic resistance. Such disorders can develop as a result of increased tone of the smooth muscles of the lower respiratory tract, with hypertrophy or swelling of the mucous membranes (for example, with acute respiratory viral infections), accumulation of mucus, purulent discharge, in the presence of a tumor or foreign body, dysregulation of the upper respiratory tract and other cases.
The presence of obstructive changes in the airways is judged by a decrease in POS, FVC 1, MOS 25, MOS 50, MOS 75, MOS 25-75, MOS 75-85, the value of the Tiffno test index and MVL. The Tiffno test rate is normally 70-85%, a decrease to 60% is regarded as a sign of a moderate disorder, and to 40% as a pronounced disorder of bronchial obstruction. In addition, with obstructive disorders, indicators such as residual volume, functional residual capacity and total lung capacity increase.
Restrictive disorders are a decrease in the expansion of the lungs during inspiration, a decrease in respiratory excursions of the lungs. These disorders can develop due to decreased compliance of the lungs, damage to the chest, the presence of adhesions, accumulation of fluid, purulent contents, blood in the pleural cavity, weakness of the respiratory muscles, impaired transmission of excitation at neuromuscular synapses and other reasons.
The presence of restrictive changes in the lungs is determined by a decrease in vital capacity (at least 20% of the proper value) and a decrease in the MVL (nonspecific indicator), as well as a decrease in lung compliance and, in some cases, an increase in the Tiffno test score (more than 85%). With restrictive disorders, total lung capacity, functional residual capacity, and residual volume are reduced.
The conclusion about mixed (obstructive and restrictive) disorders of the external respiration system is made with the simultaneous presence of changes in the above flow and volume indicators.
Lung volumes and capacities
Tidal volume is the volume of air that a person inhales and exhales at rest; in an adult it is 500 ml.
The inspiratory reserve volume is the maximum volume of air that a person can inhale after a quiet inhalation; its size is 1.5-1.8 liters.
Expiratory reserve volume is the maximum volume of air that a person can exhale after a quiet exhalation; this volume is 1-1.5 liters.
Residual volume is the volume of air that remains in the lungs after maximum exhalation; The residual volume is 1 -1.5 liters.
Rice. 3. Changes in tidal volume, pleural and alveolar pressure during lung ventilation
Vital capacity (VC) is the maximum volume of air that a person can exhale after the deepest breath. Vital capacity includes inspiratory reserve volume, tidal volume and expiratory reserve volume. The vital capacity of the lungs is determined by a spirometer, and the method for determining it is called spirometry. Vital capacity in men is 4-5.5 l, and in women - 3-4.5 l. It is greater in a standing position than in a sitting or lying position. Physical training leads to an increase in vital capacity (Fig. 4).
Rice. 4. Spirogram of pulmonary volumes and capacities
Functional residual capacity (FRC) is the volume of air in the lungs after a quiet exhalation. FRC is the sum of expiratory reserve volume and residual volume and is equal to 2.5 liters.
Total lung capacity (TLC) is the volume of air in the lungs at the end of a full inhalation. TLC includes residual volume and vital capacity of the lungs.
Dead space is formed by air that is located in the airways and does not participate in gas exchange. When you inhale, the last portions of atmospheric air enter the dead space and, without changing its composition, leave it when you exhale. The dead space volume is about 150 ml, or approximately 1/3 of the tidal volume during quiet breathing. This means that out of 500 ml of inhaled air, only 350 ml enters the alveoli. By the end of a quiet exhalation, there is about 2500 ml of air (FRC) in the alveoli, so with each quiet inhalation, only 1/7 of the alveolar air is renewed.
External respiration: research and indicators. Human lung capacity
.....
It remains to remember such a small detail, in fact, for the sake of which the house is being built - these are the residents. For people to live, they need fresh air, which must be renewed.
How many cubic meters of air should be renewed in the house per hour? How many cubes are actually updated per hour in the room where you are now?
There is no single answer to this question.
Formally, in accordance with Soviet-era SNiP, three cubic meters per hour per square meter, in other words, in an ordinary room with a ceiling height of 2.5 - 3 meters, the air should be renewed once per hour!
Do you always need fresh air?
No, not always. In rooms where there are no people and no air consumers technological processes, air exchange is not needed at all. Why is there air exchange there? In the house in conservation mode (with low temperature) it is generally harmful! With new (fresh) air, rooms can become filled with unnecessary moisture and dust.
How much air does a person need to breathe?
“Adults, at rest, produce an average of 16 to 20 respiratory movements per minute. The volume of each breath is usually about 500 ml, hence the minute volume of breathing is 500 * 16 = 8000 ml. In a newborn, the respiratory rate is 60-70 breaths per minute, by 5 years it decreases to 26, and by 15-20 years, to 20 per minute. During work, movement, and fever (in conditions of increased metabolism), the number of respiratory movements per minute increases. Ventilation of the lungs, equal to an average of 8 liters at rest, with severe physical labor increases 20 times."
Since at home they rarely do heavy physical work, and if they do, they sometimes open the windows wide, not even for breathing, but to cool down. We will assume that at home the breathing norm can be exceeded, say 3-4 times. So one person uses approximately 2 m3 of air per hour. Since fresh air is mixed with old air in an unclear ratio, let’s assume that 20% of the air in the cube is renewed, which means that one person needs (even with a fourfold supply) 10 m3 of air per hour.
Logic dictates that the intensity of air exchange should depend not on the volume of the room (once per hour), but on the number of people in this room. One thing living room with one tenant, another thing, for example, is a classroom in which more than 30 people are constantly present. In a bedroom with a volume of 30 m3, a change of 10 m3/hour is sufficient - this is 1/3 of the air change in the room. And in a crowded auditorium, 130 m3 and twice the air exchange per hour will not be enough - for 30 people you need 300 m3 of air.
Engineering companies successfully speculate on similar considerations, imposing powerful ventilation and expensive energy recovery (energy-saving) installations on naive cottage owners.
How many square meters of house do you have?
600? Great... 600m2 area *3m height = 1800m3 air. You need to replace 1800 cubic meters of air in an hour according to the requirements of SNiP - no less! This means that in winter (-20 C) 24 kW/hour or 576 kW per day will be spent on heating such a volume of air per hour.
Almost 600 kW per day!!! However….
Well, you don't want to suffocate, do you?
Of course not!
Moreover, please note, we are not inventing anything; SNiP is an official document. Now you understand how urgently you need a recovery system that will save you up to 60% of these energy costs, because the exhaust air (thrown out into the street) will transfer some of the heat to fresh air, having preheated it! Great?!
Great…
And this is said at a time when such a volume of air is actually enough for comfortable breathing of 180 people! And in that house only 4-6 people will live (including servants).
Change the air once per hour!!! While the supply of breathing air in the house is 600 m2, such that if the whole family breathes continuously, it can only be “breathed” in two days – 45 hours.
What kind of air exchange occurs in our apartments?
IN ordinary apartment 80 m2 with a ceiling height of 2.65 m, the volume of the premises is 200 m3. Such apartments are connected to the common ventilation duct. the pillar is 11.6 km high. This means that the air from the ventilation duct should exit at a speed of 11.6 km/h or 3.2 m/sec! I climbed onto the roof - the air duct is in perfect order (not blocked, as is usually the case), everyone lives in the apartments and does not spare air. There is no such flow there, not even a trace!
So what kind of air exchange should there really be in a cottage?, because we are considering exactly this case.
If there is no or little environmentally harmful fumes from objects or other negative factors affecting air quality in the house, then the flow of fresh air (renewal) per person, even with a reserve, should be approximately 10 m3/hour. This means for a family (5 people) it will be 50 m3/hour, and what difference does it make where this family lives??? One family lives in small apartment 50 m2 with ceilings of 2.5 m, and another family lives in a palace of 1000 m2 with ceilings of 3.5 m, and according to SNiPs it turns out that 3500 m3 of air in the palace needs to be changed every hour??? Is it that because the family lives in the palace, they will breathe 70 times more?! Obvious absurdity! Such people breathe no more than ordinary citizens - I saw it myself. Otherwise, to blow (ventilate) the palace, it would be necessary to borrow a turbine from the wind tunnel in Zhukovsky, while everyone knows that palaces have always managed without turbines and fans since ancient times. Problem in the concept...
Only with very strong physical activity are we able to increase inhaled (exhaled) volume of air four times (i.e. up to 2/3 of three liters), thus obtaining two thirds of the normal lung volume (2 liters - vital capacity- VEL). In the same way, with a strong exhalation, a person can exhale an additional 1.5 liters of half a liter - reserve volume. The maximum volume or total capacity of the lungs may exceed 3 liters. For some it reaches 5 or more liters (for example, trained athletes, athletes, etc.).
Minute and daily volume, taking into account different physical states of the body
On average, lying completely at rest, people inhale and exhale 5 liters of air (0.3 m3/h) every minute; when standing - 7 liters, while walking - 10 liters, during simple work - 25, with heavy loads - 40 liters, and when highest voltage, for example, during sports competitions - 60 liters or more (3.6 m3/h). For reference, one m3 contains 1000 liters.So how much air does a person inhale and exhale per day? On average, we pass through our lungs 15 - 20 cubic meters of air per day, and approximately 6,000 cubic meters per year. meters. During the longest life, a person is not able to use half a cubic kilometer of inhaled air.
Respiratory rate of children and adults
Typically, the breathing rate in a mature organism is 12 times per minute, in a child it is two times higher.Table 1. Dependence of breathing frequency, tidal volume (absolute and per 1 kg of body weight) on age according to N. A. Shalkova.
..how many liters of air does a person need per day?
The amount of air pumped by human lungs in one minute in technology (and not only in technology) is called pulmonary ventilation. This value varies over a fairly wide range. It depends both on the physical and physiological properties of a particular individual, and on the type of his activity. Usually, when calculating life support systems, it is assumed that at rest, pulmonary ventilation is 6 l/min, and during light physical activity - approx. 20 l/min, and during heavy work - 60 or more l/min.
So, if I understood your question correctly, then 8.6-16.0 cubic meters of air will be pumped through a person’s lungs per day (if they haven’t plowed on it).
If a person sits in an unventilated room, then this is a completely different problem, also easily solved. In its standard form, the formula for people staying in a closed chamber without ventilation usually determines the time they can sit there, and has the following form:
T=[(V-0.08*n)*(Kd-K)]:M*n (oh, it’s awkward to write formulas in mail). Here T is the permissible time of stay in the chamber, hours, V is the volume of the chamber, l, n is the number of people in the chamber, Kd is the permissible concentration of carbon dioxide, l/l, K is the initial concentration of carbon dioxide before closing the chamber, l/l , M - average carbon dioxide emission by one person in the chamber, l/hour. Since we are faced with another task - to determine the required volume of the chamber for a known time spent in it, we will transform this formula and obtain:
V=(T*M+0.08Kd-0.08K):(Kd-K)
Next we substitute the parameters.
You wrote that the required time is one day, which means T=24; The release of carbon dioxide, if a person sits there for a day and is not preparing for a boxing match for the world champion title, I think can be taken as the daily average, that is, 30 l/hour (if more, substitute the required one; less is unlikely). Kd, that is, the permissible concentration of carbon dioxide. There is a lot of room for imagination here. Who is sitting - young healthy people or sickly and frail people? Children? Old people? In general, if the regime is gentle, then this value cannot be increased above 0.5%, and if young healthy people who can tolerate a possible mild headache jokingly, then nothing terrible will happen even at 1% per day. Yes, by the way, you write about hypoxia, so this is precisely the lack of oxygen, oxygen starvation. We calculate using carbon dioxide, so a possible unpleasant condition will be called hypercopnia, that is, excess CO2.
So, we take Kd in the range of 0.005-0.01, that is, from half a percent to one percent. Well, K knows that if the air is not polluted, then it is 0.03%, that is, 0.0003.
If we substitute and round, we will end up with the required chamber volume for one person from 72,000 to 144,000 liters, or from 72 to 144 cubic meters. The difference, naturally, is due to the fact that we considered the permissible concentration to be within 0.5-1%. In a volume of 72 cubic meters per day, one organism will inhale to approximately one percent, in 144 - up to half a percent.
In general, I want to say that it is better to carry out such experiments with gas analyzers for oxygen and carbon dioxide in the chamber. If it is difficult to get equipment, you can at least buy glass tubes for express analysis and do it every hour. The fact is that sometimes you come across individual individuals who consume oxygen (and, accordingly, release carbon dioxide) in very large quantities. For example, we have one of these (I work on the Mir submersibles), his gas exchange is approximately twice as high as that of normal people. Further, smoking is strictly forbidden in this volume, and if you imprison a smoker, it is better for him to abstain from smoking for a day, otherwise he will inhale carbon monoxide, and this is worse than CO2. Well, the best thing, of course, is to organize some kind of simple life support system in a closed space. Then even if you sat in three cubic meters for a week, you would have something to drink and eat.
