CHAPTER 2: THORAX PART 1: SURFACE ANATOMY

Question 1

How can Internal Thoracic Artery be used in the Treatment
of Coronary Artery Disease?

Answer 1

In patients with occlusive coronary disease caused by atherosclerosis, the diseased arterial segment can be bypassed by inserting a graft.

The graft most commonly used is the great
saphenous vein of the leg (see page 453).

In some patients,
the myocardium can be revascularized by surgically mobilizing one of the internal thoracic arteries and joining its distal
cut end to a coronary artery

Question 2

Lymph Drainage of the Thoracic Wall

Answer 2

The lymph drainage of the skin of the anterior chest wall passes to the anterior axillary lymph nodes; that from the posterior chest wall passes to the posterior axillary nodes
(Fig. 2.18).

The lymph drainage of the intercostal spaces
passes forward to the internal thoracic nodes,situated along the internal thoracic artery, and posteriorly to the posterior intercostal nodes and the para-aortic nodes in the posterior mediastinum.

The lymphatic drainage of the breast is
described on page 337.

Question 3

How to locate the suprasternal notch?

Answer 3

The suprasternal notch is the superior margin of the
manubrium sterniand iseasily felt between the prominent medial endsof theclavicles in the midline (Figs. 2.19 and
2.20).

It lies opposite the lower border of the body of the
2nd thoracic vertebra (see Fig. 2.2).

Question 4

How will u locate the sternal angle ( angle of Louis)

Answer 4

The sternal angle (angle of Louis) is the angle made
between the manubrium and the body of the sternum (see
Figs. 2.19 and 2.20).

It lies opposite the intervertebral disc
between the 4th and 5th thoracic vertebrae (see Fig. 2.2).

The
position of the sternal angle can easily be felt and is oftenseen as a transverse ridge.

The finger moved to the right or
to the left will pass directly onto the 2nd costal cartilage and
then the 2nd rib.

All ribs may be counted from this point.

Question 5

How are you going to count the ribs in a very muscular male?

Answer 5

Occasionally in a very muscular male, the ribs and intercostal
spaces are often obscured by large pectoral muscles.

In these cases, it may be easier to count up from the 12th rib.

Question 6

Anatomic and Physiologic Changes in the Thorax
with Aging

Certain anatomic and physiologic changes take place in the
thorax with advancing years:

Answer 6

■■ The rib cage becomes more rigid and loses its elasticity as the result of calcification and even ossification of the costal cartilages; this also alters their usual radiographic appearance.
■■ The stooped posture (kyphosis), so often seen in the old because of degeneration of the intervertebral discs, decreases the chest capacity.
■■ Disuse atrophy of the thoracic and abdominal muscles can result in poor respiratory movements.
■■ Degeneration of the elastic tissue in the lungs and bronchi results in impairment of the movement of expiration.

These changes, when severe, diminish the efficiency of respiratory movements and impair the ability of the individual to withstand respiratory disease

Question 7

Can the 1st rib be palpated?

Answer 7

The 1st rib lies deep to the clavicle and cannot be palpated.

Question 8

How can the remaining ribs be felt?

Answer 8

The lateral surfaces of the remaining ribs can be felt by
pressing the fingers upward into the axilla and drawing
them downward over the lateral surface of the chest wall.

Question 9

How can the 12th rib be used to identify a particular rib?

Answer 9

The 12th rib can be used to identify a particular rib by
counting from below.

However, in some individuals, the
12th rib is very short and difficult to feel.

For this reason,
an alternative method may be used to identify ribs by first palpating the sternal angle and the second costal cartilage

Question 10

Where does the male nipple lies?

Answer 10

In the male, the nipple usually lies in the fourth
intercostal space about 4 in. (10 cm) from the midline.

***In the female, its position is not constant

Question 11

What is the reason for the apex beat?

Answer 11

The apex of the heart is formed by the lower portion
of the left ventricle.

The apex beat is caused by the
apex of the heart being thrust forward against the thoracic wall as the heart contracts.

(The heart is thrust
forward with each ventricular contraction because of
the ejection of blood from the left ventricle into the
aorta; the force of the blood in the aorta tends to cause the curved aorta to straighten slightly, thus pushing the heart forward.)

Question 12

How can you palpate the apex beat?

Answer 12

The apex beat can usually be felt
by placing the flat of the hand on the chest wall over
the heart.

After the area of cardiac pulsation has been
determined, the apex beat is accurately localized by
placing two fingers over the intercostal spaces and
moving them until the point of maximum pulsation
is found.

The apex beat is normally found in the fifth
left intercostal space 3.5 in. (9 cm) from the midline.
Should you have difficulty in finding the apex beat,
have the patient lean forward in the sitting position.
In a female with pendulous breasts, the examining
fingers should gently raise the left breast from
below as the intercostal spaces are palpated.

Question 13

What is the location of the apex beat?

Answer 13

The apex beat is normally found in the fifth
left intercostal space 3.5 in. (9 cm) from the midline.

Should you have difficulty in finding the apex beat,
have the patient lean forward in the sitting position.

In a female with pendulous breasts, the examining
fingers should gently raise the left breast from
below as the intercostal spaces are palpated.

“Heart is shape like a fist and we do have five fingers”.

Question 14

What forms the anterior axillary forld?

Answer 14

The anterior fold is formed by the lower border of the pectoralis major muscle (see Figs. 2.19 and 2.20).

This can be
made to stand out by asking the patient to press a hand hard against the hip.

Question 15

What forms the posterior axillary fold ?

Answer 15

The posterior fold is formed by the
tendon of the latissimus dorsi muscle as it passes around
the lower border of the teres major muscle.

Question 16

How can you palpate the spinous process of the thoracic vertebrae?

Answer 16

The spinous processes of the thoracic vertebrae can be palpated in the midline posteriorly (Fig. 2.22).

The index
finger should be placed on the skin in the midline on the posterior surface of the neck and drawn downward in the nuchal groove.

The first spinous process to be felt is that
of the seventh cervical vertebrae (vertebra prominens).
Below this level are the overlapping

spines of the thoracic
vertebrae.

The spines of C1 to 6 vertebrae are covered
by a large ligament, the ligamentum nuchae. It should
be noted that the tip of a spinous process of a thoracic
vertebra lies posterior to the body of the next vertebra
below.

Question 17

How can you palpate the scapula?

Answer 17

The scapula (shoulder blade) is flat and triangular in
shape and is located on the upper part of the posterior
surface of the thorax.

The superior angle lies opposite the
spine of the second thoracic vertebra (see Figs. 2.20 and
2.22).

The spine of the scapula is subcutaneous, and the
root of the spine lies on a level with the spine of the third
thoracic vertebra (see Figs. 2.21 and 2.22).

Question 18

Where can you palpate the inferior angle of the scapula?

Answer 18

The inferior
angle lies on a level with the spine of the seventh thoracic
vertebra (see Figs. 2.20 and 2.22).

Question 19

Lines of Orientation
Several imaginary lines are sometimes used to describe surface
locations on the anterior and posterior chest walls.

Answer 19

• Midsternal line
• Midclavicular line
• Anterior axillary line
• Posterior axillary line
• Midaxillary line
• Scapular line

Question 20

Where is the Midsternal line?

Answer 20

Midsternal line: Lies in the median plane over the sternum

Question 21

What is the Midclavicular line?

Answer 21

Midclavicular line: Runs vertically downward from the
midpoint of the clavicle (see Fig. 2.21)

Question 22

Anterior axillary line

Answer 22

Runs vertically downward from
the anterior axillary fold (see Fig. 2.21)

Question 23

Posterior axillary line:

Answer 23

Runs vertically downward from
the posterior axillary fold

Question 24

Midaxillary line

Answer 24

Midaxillary line: Runs vertically downward from a
point situated midway between the anterior and posterior
axillary folds

Question 25

Scapular line

Answer 25

Runs vertically downward on the posterior
wall of the thorax (see Fig. 2.22), passing through
the inferior angle of the scapula (arms at the sides)

Question 26

When one is examining the chest from in front, what is the most important landmark?.

Answer 26

Rib and Costal Cartilage Identification
When one is examining the chest from in front, the sternal angle is an important landmark.

When one is examining the chest from in front, the sternal angle is an important landmark. Its position can easily be felt and often be seen by the presence of a transverse ridge.

The
finger moved to the right or to the left passes directly onto the second costal cartilage and then the 2nd rib.

All other ribs can
be counted from this point.

The 12th rib can usually be felt from
behind, but in some obese persons this may prove difficult.ge. The finger moved to the right or to the left passes directly onto the second costal cartilage and then the 2nd rib.

All other ribs can
be counted from this point.

The 12th rib can usually be felt from
behind, but in some obese persons this may prove difficult.

Question 27

Where can you locate the trachea?

Answer 27

The trachea extends from the lower border of the cricoid
cartilage(opposite the body of the 6th cervical vertebra) in the neck to the level of the sternal angle in the thorax

. It commences in the midline and ends just to
the right of the midline by dividing into the right and the left principal bronchi.

At the root of the neck, it may be
palpated in the midline in the suprasternal notch.

(Fig. 2.23)

Question 28

How can you identify the apex of the lungs?

Answer 28

The apex of the lung projects into the neck. It can be
mapped out on the anterior surface of the body by
drawing a curved line, convex upward, from the sternoclavicular joint to a point 1 in. (2.5 cm) above the junction of the medial and intermediate thirds of the clavicle (see
Fig. 2.23).

Question 29

Where does the anterior border of the right lungs start?

Answer 29

The anterior border of the right lung begins behind the
sternoclavicular joint and runs downward, almost reaching the midline behind the sternal angle.

It then continues
downward until it reaches the xiphisternal joint (see Fig.
2.23).

Question 30

Wher can you find the anterior border of the left lung?

Answer 30

The anterior border of the left lung has a similar
course, but at the level of the fourth costal cartilage it deviates laterally and extends for a variable distance beyond the lateral margin of the sternum to form the cardiac notch
(see Fig. 2.23).

Question 31

What forms the cardiac notch?

Answer 31

This notch is produced by the heart displacing
the lung to the left.

The anterior border then turns
sharply downward to the level of the xiphisternal joint.

Question 32

Describe the lower border of the lung in midinspiration?

Answer 32

The lower border of the lung in midinspiration follows
a curving line, which crosses the 6th rib in the midclavicular line and the 8th rib in the midaxillary line, and reaches the 10th rib adjacent to the vertebral column posteriorly
(Figs. 2.23, 2.24, and 2.25).

It is important to understand
that the level of the inferior border of the lung changes during inspiration and expiration.

Question 33

Describe the posterior border of the lung.

Answer 33

The posterior border of the lung extends downward
from the spinous process of the 7th cervical vertebra to
the level of the 10th thoracic vertebra and lies about 1.5 in. (4 cm) from the midline (Fig. 2.24).

Question 34

Identify the oblique fissure of the lung.

Answer 34

The oblique fissure of the lung can be indicated on the
surface by a line drawn from the root of the spineof the scapula obliquely downward, laterally and anteriorly, following
the course of the 6th rib to the sixth costochondral
junction.

In the left lung, the upper lobe lies above and
anterior to this line; the lower lobe lies below and posterior
to it (see Figs. 2.23 and 2.24).

Question 35

How can you identify the additional fissure of the right lung?

Answer 35

In the right lung is an additional fissure, the horizontal

• *fissure,** which may be represented by a line drawn horizontally
• *along the fourth costal cartilage to meet the oblique**
• *fissure in the midaxillary line** (see Figs. 2.23 and2.25).

Above the horizontal fissure lies the upper lobe and below it lies the middle lobe; below and posterior to the oblique fissure lies the lower lobe

Question 36

What is pleural refleciton?

Answer 36

The boundaries of the pleural sac can be marked out as lines on the surface of the body.

The lines, which indicate the
limits of the parietal pleura where it lies close to the body surface, are referred to as the lines of pleural reflection.
The cervical pleura bulges upward into the neck and
has a surface marking identical to that of the apex of the lung. A curved line may be drawn, convex upward, from
the sternoclavicular joint to a point 1 in. (2.5 cm) above the junction of the medial and intermediate thirds of the clavicle (see Fig. 2.23).

Question 37

anterior border of the right pleura

Answer 37

The anterior border of the right pleura runs down
behind the sternoclavicular joint, almost reaching the midline
behind the sternal angle. It then continues downward
until it reaches the xiphisternal joint.

Question 38

The anterior border
of the left pleura

Answer 38

The anterior border
of the left pleura has a similar course, but at the level of the fourth costal cartilage it deviates laterally and extends to the lateral margin of the sternum to form the cardiac notch.

(Note that the pleural cardiac notch is not as large as the cardiac notch of the lung.) It then turns sharply downward to the xiphisternal joint (see Fig. 2.23).

Question 39

Describe the lower border of the pleura.

Answer 39

The lower border of the pleura on both sides follows a
curved line, which crosses the 8th rib in the midclavicular
line and the 10th rib in the midaxillary line, and reaches the
12th rib adjacent to the vertebral column—that is, at the
lateral border of the erector spinae muscle (see Figs. 2.23,
2.24, and 2.25).

Question 40

What is the costodiaphragmatic
recess?

Answer 40

Note that the lower margins of the lungs
cross the 6th, 8th, and 10th ribs at the midclavicular lines, the midaxillary lines, and the sides of the vertebral column, respectively; the lower margins of the pleura cross, at the
same points, the 8th, 10th, and 12th ribs, respectively.

The distance between the two borders corresponds to the costodiaphragmatic
recess (see page 62).

Question 41

Pleural Reflections

Answer 41

It is hardly necessary to emphasize the importance of knowing the surface markings of the pleural reflections and the lobes of the lungs.

When listening to the breath sounds of the respiratory
tract, it should be possible to have a mental image of
the structures that lie beneath the stethoscope.
The cervical dome of the pleura and the apex of the lungs extend up into the neck so that at their highest point they lie about 1 in. (2.5 cm) above the clavicle (see Figs. 2.6, 2.13, and
2.23).

Consequently, they are vulnerable to stab wounds in the root of the neck or to damage by an anesthetist’s needle when a nerve block of the lower trunk of the brachial plexus is being
performed.

Remember also that the lower limit of the pleural reflection, as seen from the back, may be damaged during a nephrectomy.
The pleura crosses the 12th rib and may be damaged
during removal of the kidney through an incision in the loin.

Question 42

For practical purposes, the heart may be considered to have
both an apex and four borders

Question 43

Describe the apex of the heart.

Answer 43

The apex, formed by the left ventricle, corresponds to
the apex beat and is found in the fifth left intercostal space
3.5 in. (9 cm) from the midline (Fig. 2.26)

from the edge of the sternum to a point on the third right costal cartilage 0.5 in. (1.3 cm) from the edge of the sternum
(see Fig. 2.26).

Question 44

Describe the right border of the heart.

Answer 44

The right border, formed by the right atrium, extends
from a point on the third right costal cartilage 0.5 in. (1.3
cm) from the edge of the sternum downward to a point on the 6th right costal cartilage 0.5 in. (1.3 cm) from the edge
of the sternum (see Fig. 2.26).

Question 45

Describe the left border of the heart.

Answer 45

The left border, formed by the left ventricle, extends
from a point on the 2nd left costal cartilage 0.5 in. (1.3 cm)
from the edge of the sternum to the apex beat of the heart
(see Fig. 2.26).

Question 46

Describe the inferior border of the heart.

Answer 46

The inferior border, formed by the right ventricle and
the apical part of the left ventricle, extends from the sixth
right costal cartilage 0.5 in. (1.3 cm) from the sternum to
the apex beat (see Fig. 2.26).

Question 47

Position and Enlargement of the Heart

Answer 47

Position and Enlargement of the Heart
The surface markings of the heart and the position of the apex beat may enable a physician to determine whether the heart has shifted its position in relation to the chest wall or whether
the heart is enlarged by disease.

The apex beat can often be
seen and almost always can be felt.

The position of the margins
of the heart can be determined by percussion.

Question 48

What lies behind the manubrium sterni?

Answer 48

The arch of the aorta and the roots of the brachiocephalic
and left common carotid arteries lie behind the manubrium sterni (Fig. 2.2).

The superior vena cava and the terminal parts of the
right and left brachiocephalic veins also lie behind the
manubrium stern

Question 49

The internal thoracic vessels run vertically downward,
posterior to the costal cartilages, 0.5 in. (1.3 cm) lateral to
the edge of the sternum (see Figs. 2.9 and 2.10), as far as the sixth intercostal space.

The intercostal vessels and nerve (“vein, artery, nerve”—
VAN—is the order from above downward) are situated
immediately below their corresponding ribs (see Fig. 2.8).

Question 50

Why is the mammary gland is clinically a very important structure?

Answer 50

The mammary gland is clinically a very important structure.
Because it is closely related to the pectoral muscles
and its main lymph drainage is into the axillary lymph
nodes, it will be fully described with the Upper Limb in
Chapter 9. To summarize briefly, the mammary gland lies in the superficial fascia covering the anterior chest wall
(Fig. 2.20).

In the child and in men, it is rudimentary. In
the female after puberty, it enlarges and assumes its hemispherical shape.

Question 51

Where does the mammary gland lies in the young adult female?

Answer 51

In the young adult female, it overlies the
2nd to 6th ribs and their costal cartilages and extends from
the lateral margin of the sternum to the midaxillary line.

Its upper lateral edge extends around the lower border of the pectoralis major and enters the axilla.

In middle-aged
multiparous women, the breasts may be large and pendulous.

In older women past menopause, the adipose tissue
of the breast may become reduced in amount and the
hemispherical shape lost; the breasts then become smaller, and the overlying skin is wrinkled