Determination of the lungs' boundariesLimits of the lungs in the norm( table)

The definition of lung boundaries is of great importance for the diagnosis of many pathological conditions. The ability to percussionally reveal the displacement of the thorax organs in one direction or another allows one to suspect the presence of a certain disease at the stage of examining the patient without using additional methods of investigation( in particular, radiographic ones).

How to measure lung boundaries? Of course, you can use the instrumental methods of diagnosis, take an X-ray and evaluate how the lungs are located relative to the skeletal structure of the chest. However, it is best to do this without exposing the patient to radiation. Border of the lungs Determination of the boundaries of the lungs during the inspection is carried out by topographic percussion. What it is? Percussion - a study based on the identification of sounds that occur when tapping on the surface of a person's body. The sound changes depending on which area the research is in. Above the parenchymal organs( liver) or muscles, it turns out to be deaf, above the hollow organs( intestine) - tympanic, and above the air-filled lungs acquires a special sound( pulmonary percussion sound).

This study is being implemented as follows. One hand is placed palm on the study area, two or one finger of the second hand strikes the middle finger of the first( plessimetre), like a hammer on the anvil. As a result, you can hear one of the options percussion sound, which have already been mentioned above.

Percussion is comparative( sound is evaluated in symmetrical areas of the chest) and topographic. The latter is just designed to determine the boundaries of the lungs.

How to correctly perform topographic percussion?

The finger-plessimeter is set to the point at which the examination begins( for example, when determining the upper border of the lung over the anterior surface, it starts over the middle part of the clavicle), and then shifts to the point where the approximate measurement should end. The border is defined in the area where the pulmonary percussion sound becomes blunt. Boundaries of the human lungs The finger-plessimeter should lie parallel to the desired boundary for the convenience of the investigation. The offset step is approximately 1 cm. Topographic percussion, unlike the comparative one, is performed by a gentle( silent) tapping.

The upper limit of the

The position of the apices of the lung is assessed both in front and in the back. On the anterior surface of the chest, the clavicle serves as a guide, on the back - the seventh cervical vertebra( it has a long spinous process along which it can easily be distinguished from other vertebrae).

The upper border of the lung is normal as follows:

  • Anteriorly above the clavicle level by 30-40 mm.
  • The back is usually at the same level as the seventh cervical vertebra.

The study should be performed as follows:

  1. The finger-plessimetric finger is placed in front of the collarbone( approximately in the projection of its middle), and then shifts upward and toward the interior until the percussion sound becomes blunt.
  2. At the back of the study begin from the middle of the shoulder blade, and then the finger-plessimeter moves upward so as to be on the side of the seventh cervical vertebra. Percussion is performed until a dull sound appears.

Upper border of the lungs

Offset of the upper border of the lungs

The displacement of the boundaries upwards occurs due to the excessive airiness of the lung tissue. This condition is typical for emphysema - a disease in which the walls of the alveoli become overextended, and in some cases, their destruction with the formation of cavities( bulls).Changes in the lungs with emphysema are irreversible, the alveoli swell, the ability to subside is lost, the elasticity is sharply reduced.

The boundaries of the human lungs( in this case, the top borders) can be shifted downward. This is due to a decrease in airiness of the lung tissue, a condition that is a sign of inflammation or its effects( proliferation of connective tissue and wrinkling of the lung).Limits of the lungs( upper), located below the normal level, is a diagnostic sign of pathologies such as tuberculosis, pneumonia, pneumosclerosis.

Lower limit of

To measure it you need to know the main topographic lines of the chest. The method is based on moving the researcher's hands along these lines from top to bottom until the pulmonary percussion sound changes to a blunt sound. It should also be known that the front left lung border is not symmetrical to the right one due to the presence of a pocket for the heart. Determination of the border In front, the lower border of the lungs is determined along the line running along the lateral surface of the sternum, as well as along a line that descends downwards from the middle of the clavicle.

Sideways, three axillary lines - anterior, middle and posterior, that begin at the front edge, center and posterior margin of the axilla respectively, are important points. Behind, the edge of the lungs is determined with respect to the line descending from the angle of the scapula, and the line located to the side of the spine.

Displacement of the lower border of the lungs

It should be noted that in the process of breathing the volume of this organ changes. Therefore, the lower border of the lungs are normally displaced 20-40 mm up and down. A stable change in the position of the border indicates a pathological process in the chest or abdominal cavity. Boundaries of the lungs are normal The lungs increase excessively with emphysema, which results in a bilateral shift of the borders downwards. Other causes may be hypotension of the diaphragm and pronounced omission of the abdominal organs. The lower border is displaced downwards on one side in the case of compensatory expansion of the healthy lung, when the second is in a collapsed state as a result of, for example, total pneumothorax, hydrothorax, etc.

The upper border of the lungs moves usually due to the wrinkling of the latter( pneumosclerosis), the fall of the share as a result of obstructionbronchus, congestion in the pleural cavity of exudate( as a result of which the lung collapses and contracts to the root).Pathological conditions in the abdominal cavity are also capable of shifting the pulmonary boundaries to the top: for example, fluid accumulation( ascites) or air( with perforation of the hollow organ).

Limits of lungs OK: table

Bottom borders in adult

Areas of investigation

Right lung

Left lung

Line at lateral surface of sternum

5 intercostal space


Line descended from middle of clavicle

6 rib


Line originatingfrom the anterior edge of the axillary basin

7 rib

7 rib

Line from the center of the axillary basin

8 rib

8 rib

Line from the back edge of the axillary basin

9 rib

9 rib

Nia, descending from the corner edge 10 of the blade

line rib 10 on the side of the spine 11

thoracic vertebrae 11 thoracic vertebrae

Location upper lung boundaries described above.

Changes in the index depending on the physique

In asthenics, the lungs are elongated in the longitudinal direction, so they often fall somewhat below the generally accepted norm, ending not in the ribs, but in the intercostal spaces. For hypersthenics, on the contrary, the higher position of the lower boundary is characteristic. The lungs are broad and flattened in shape.

How are the baby's lung borders located?

Strictly speaking, the borders of the lungs in children practically correspond to those of an adult. The tops of this organ in children who have not reached the preschool age, are not determined. Later they are revealed in front on 20-40 mm above the middle of the clavicle, from behind - at the level of the seventh cervical vertebra.Limits of lungs in children

The location of the lower bounds is shown in the table below.

Boundary of the lungs( table)

Area of ​​study

Age under 10 years

Age over 10 years

Line from the middle of the clavicle

Right: 6 rib

Right: 6 rib

Line originating from the center of the axilla

Right:8 Rib

Left: 9 Rib

Right: 8 Rib

Left: 8 Rib

The line that descends from the blade angle

Right: 9-10 Rib

Left: 10 Rib

Right: 10 Rib

Left: 10 Rib

The causes of the displacement of the pulmonaryboundaries in children up or downtion of normal values ​​are the same as in adults.

How to determine the mobility of the lower edge of the organ?

Above it has been said that when breathing, the lower limits shift relative to normal parameters due to the expansion of the lungs on inspiration and a decrease in exhalation. Normally, such a shift is possible within 20-40 mm upward from the lower boundary and as much downward.

The mobility determination is carried out on three main lines starting from the middle of the clavicle, the center of the axilla and the angle of the scapula. The study is carried out as follows. First determine the position of the lower border and make a mark on the skin( you can handle).Then the patient is asked to take a deep breath and hold his breath, after which they again find the lower limit and make a mark. And finally determine the position of the lung with the maximum expiration. Now, focusing on the marks, one can judge how the lung moves relative to its lower limit.

In some diseases, the mobility of the lungs is markedly reduced. For example, this occurs with spikes or a large amount of exudate in the pleural cavities, loss of easy elasticity in emphysema, etc.

Difficulty in conducting topographic percussion

This method of research is not easy and requires certain skills, and better - more experience. The difficulties encountered in its application are usually associated with improper execution techniques. As for the anatomical features that can create a problem for the researcher, this is mainly expressed obesity. In general, it is easiest to perform percussion on asthenics. The sound is clear and loud.Lower border of the lungs What should be done to easily determine the boundaries of the lung?

  1. Know exactly where, how and exactly which borders to look for. Good theoretical preparation is the key to success.
  2. Move from clear sound to blunt.
  3. The finger-pletsimetr should lie parallel to the defined boundary, move should be perpendicular to it.
  4. Hands should be relaxed. Percussion does not require significant effort.

And, of course, experience is very important. Practice gives confidence in their abilities.

Let's sum up

Percussion is a very important diagnostic method for research. It allows you to suspect many pathological conditions of the chest. The deviation of lung boundaries from normal indices, impaired mobility of the lower edge - the symptoms of some serious diseases, timely diagnosis of which is important for conducting full-fledged treatment.