SURFACE ANATOMY OF THE THORAX
WRITTEN BY : RAYAN S. ALBALLAA
* ANTERIOR THORACIC WALL :
- SUPRASTERNAL NOTCH is the superior margin of manubrium
sterni , and it lies opposite to the lower border of T2 .
- MANUBRIUM STERNI lies opposite to T3 & T4 .
- STERNAL ANGLE ( ANGLE OF LOUIS ) is the angle between the
manubrium and the body of the sternum forming a cartilaginous
joint called MANUBRIOSTERNAL JOINT which has a small
amount of movement possible during respiration . It lise between T4
& T5 .
- XIPHISTERNAL JOINT is the joint between the xiphoid process
( which is a cartilage ) and the body of the sternum . It's a
cartilaginous joint , and it fuses with the body of the sternum during
middle age . It lies opposite to T9 .
- SUBCOSTAL ANGLE is at the inferior end of the sternum ;
between the sternal attachments of SEVENTH COSTAL
CARTILAGES .
- COSTAL MARGIN is the lower boundary of the thorax and is
formad of
1- the costal cartilages of the 7th , 8th , 9th , ant the 10th ribs .
2- the ends of the cartilages of the 11th and 12th ribs .
The loest part of it is formed by the 10th rib and lies at the lever of L3
* DIAPHRAGM :
-THE CENTRAL TENDON lies behind the xiphisternal joint .
-RIGHT DOME is HIGHER than the LEFT DOME .
-RIGHT DOME is at the upper border of the 5th rib and left dome is
at the level of lower border of the 5th rib .
* NIPPLE :
IN MALES , it's in the 4th intercostal space , but in females in differs .
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* THE APEX OF THE HEART :
- the apex of the heart is formed by the left ventricle .
- the apex beat is caused by the apex of the heart being thrust
( pushed with a lot of force ) forward against the thoracic wall as the
heart contracts .
- you can feel the apex beat by placing the flat of your hand on the
chest wall over the heart , and then determine the area of cardiac
pulsation . after that , you place two fingers over the intercostal
spaces and you keep moving till you find the point of maximum
pulsation .
- the apex is usually found in the 5th LEFT INTERCOSTAL SPACE
3.5 in ( 9cm ) from the midline .
* THE AXILLARY FOLD :
- THE ANTERIOR FOLD is formed by the lower border of
PECTORALIS MAJOR while the POSTERIOR FOLD is formed BY
THE TENDON THE LATISSIMUS DORSI as it passes around the
lower border of TERES MAJOR .
* POSTERIOR THORACIC WALL :
- All the spines of the thoracic vertebrae can be palpated in the
midline posteriorly .
- C7 is the fist spine to be felt ( vertebra prominens ) .
- you can not feel the spines of C1-C6 because the are covered by the
LIGAMENTUM NUCHAE .
* SCAPULA :
- the superior angle lies opposite to the spine of T2 .
- the root of the spine of the scapula lies at the level of the spine of T3
– the inferior angle lies at the level of the spine of T7 .
* TRACHEA :
- extends from C6 to T4 .
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* LUNGS :
- apex of the lung projects into the neck one inch above the clavicle .
- the anterior border of the right lung begins at the sternoclavicular
joint and runs downward almost reaching the midline behind the
sternal angle . It then continues downward till it reaches the
xiphisternal joint .
- the anterior border of the left lung deviates laterally at the level of
4th costal cartilage and extends for a variable distance beyond the
lateral margin of the sternum forming the cardiac notch . and then
continues until it reaches the level of xiphisternal joint .
- the lower margin of the left lung in midrespiration crosses the 6th ,
8th , and 10th ribs .
- the posterior border of the lung extends from the spine of C7 to T10
- READ ABOUT THE FISSURES ( pages 73 & 74 )
* PLEURA :
- the lines that indicats the limits of the parietal pleura are called
LINES OF PLURAL REFLECTION .
- the cervical pleura ( cervical dome of the pleura ) extend upward
into the neck about 1 in above the clavicle .
( READ THE CLINICAL NOTE ABOUT IT )
- the lower border of the pleura crosses the 8th in the midclavicular
line and 10th in the midaxillary line and 12th adjacent to the vertebral
column .
- COSTODIPHRAGMATIC RECESS ( READ PAGE 87 ) .
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* HEART :
- the apex is found in the 5th left intercostal space 3.5 in ( 9cm ) from
the midline .
- the superior border , formed by the roots of the great vessels
extends from a point on the 2nd left costal cartilage .5 in ( 1.3 cm )
from the edge of the sternum to a point on the 3rd righr costal
cartilage .5 in ( 1.3 cm ) from the sternum .
- the right border , formed by the right atrium , extends from a point
on the 3rd right costal cartilage to a point on the 6th right costal
cartilage .5 in ( 1.3 cm ) from the sternum .
- the left border , formed by left ventricle , extends from a point on
the 2nd left costal cartilage .5 in ( 1.3 cm ) from the the sternum to the
apex of the heart ( 5th left inercostal space ) .
- the inferior border , formed by right ventricle and the apical part of
the left ventricle , extends from the 6th right costal cartilage .5 in
( 1.3 cm ) from the edge of the sternum to the apex beat .
- the position of the margins of the heart can be determined by
percussion .
- THE :
1-ARCH OF AORTA
2- ROOT OF BRACHIOCEPHALIC ARTERY
3-COMMON CAROTID ARTERY
4-SUPERIOR VENA CAVA
5-TERMINAL PARTS OF RIGHT & LEFT BRACHIOCEPHALIC
VEINS .
lie behind the manubrium sterni .
- THE INTERNAL THORACIC VESSELS run down vertically ,5 in
( 1.3 cm ) lateral to the sternum as far as the 6th intercostal space .
- THE MAMMARY GLAND in young adult female overlies THE 2nd
to the 6th ribs .
THE END
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