C H A P T E R
63
ATLAS REFERENCES:
G =
Grant’s Atlas
, 13th ed., page number
L =
LWW Atlas of Anatomy
, 1st ed., page number
N =
Netter’s Atlas
, 5th ed., plate number
R =
Color Atlas of Anatomy
, 7th ed., page number
C =
Clemente’s Atlas
, 6th ed., plate number
3
The heart and lungs are fragile organs, and the main func-
tion of the thorax is to house and protect them. The protec-
tive function of the thoracic wall is combined with mobility
to accommodate volume changes during respiration. These
two dissimilar functions, protection and flexibility, are ac-
complished by the alternating arrangement of the ribs and
intercostal muscles.
The superficial fascia of the thorax contains the usual
elements that are common to superficial fascia in all body
regions: blood vessels, lymph vessels, cutaneous nerves,
and sweat glands. In addition, the superficial fascia of the
anterior thoracic wall in the female contains the mammary
glands, which are highly specialized organs unique to the
superficial fascia of the thorax.
SURFACE ANATOMY
[G 2; L 160; N 175; C139]
The surface anatomy of the thorax can be studied on a
living subject or on the cadaver. Turn the cadaver to
the supine position and palpate the following structures
(FIG. 3.1)
:
•
Jugular notch (suprasternal notch)
•
Clavicle
•
Acromion of the scapula
•
Manubrium
•
Sternal angle
•
Body of the sternum
•
Xiphoid process
•
Costal margin
•
Anterior axillary fold (lateral border of the pectoralis
major muscle)
SKELETON OF THE THORAX
If you have previously dissected the back, review the parts
of a
thoracic vertebra
. If you have not dissected the back,
you must study the vertebrae now. Turn to pages 6 to 8,
complete that exercise, and return to this page.
Refer to a skeleton. Examine a
rib
from the midthorax
level and identify
(FIG. 3.2)
:
[G 15; L 164; N 180; R 197; C 142]
•
Head
•
Neck
•
Tubercle
•
Costal angle
•
Shaft (body)
•
Costal groove
On an articulated skeleton, note the following features:
• The
first rib
is the highest, shortest, broadest, and most
sharply curved rib.
TheThorax
FIGURE 3.1
Surface anatomy of the anterior thoracic wall.
Jugular notch
Clavicle
Acromion
Manubrium
Sternal angle
Anterior
axillary fold
Body of sternum
Xiphisternal joint
Xiphoid process
Seventh costal cartilage
Costal margin
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