Human Anatomy Vol 1

INIRODUCIION

The pectoral region lies on the front of the chest. It
essentially consists of structures which connect the
upper limb to the anterolateral chest wall. Mammary
gland lies in this region.

The followiggfeatures of the pectoral region can be seen
or felt on tHe surface of body.
1 The claaicle lies horizontally at the root of the neck,
separating it from the front of the chest. The bone is
subcutaneous, and therefore, palpable, throughout
its length. Medially, it articulates with the sternum
at the sternoclaaicular joint, and laterally with the
acromion at the acromioclaoicular joinf. Both the joints
are palpable because of the upward projecting ends
of the clavicle (Fig.3.1). The sternoclavicular joint
may be masked by the sternocleidomastoid muscle.
2 The jugulnr notch (interclavicular or suprasternal
notch) lies between the medial ends of the clavicles,
at the superior'border of the manubrium sterni.
3 The sternal angle (angle of Louis) is felt as a
transverse ridge about 5 cmbelow the jugular notch
(Fig. 3.1). It marks the manubriosternal joint.
Laterally, on either side, the second costal cartilage
joins the sternum at this level. The sternal angle thus
serves as a landmark for identification of the second
rib. Other ribs can be identified by counting
downwards from the second rib.
4 The epigastric fossn (pit of the stomach) is the
depression in the infrasternal angle. The fossa
overlies the xiphoid process, and is bounded on each
side by the seventh costal cartilage.
5 The nipple is markedly variable in position in
females. In males, and in immature females, it

-Jon Kingz

Coracoid process

Acromioclavicular joint

Acromion

Greater tubercle

Lesser tubercte

Sternoclavicular joint

and sternal angle

Anterior axillary fold

Nipple

Lateral epicondyle

Fig. 3.1: Surface landmarks: Shoulder, axilla, arm and elbow

regions (anterior aspect)

usually lies in the fourth intercostal space just

medial to the midclavicular line; or^10 cm from the

midsternal line. In fact, the position of the nipple is

variable even in males.

5 The midclarticular line passes vertically through the

middle of clavicle the tip of the ninth costal

cartilage and the midinguinal point.

7 The infraclauicular fossa (deltopectoral triangle) is a

triangular depression below the junction of the

lateral and middle thirds of the clavicle. It is

bounded medially by the pectoralis major, laterally