Chapter 2: Pectoral Region & Clavipectoral Fascia

Which best describes the site of the clavipectoral fascia?

• A thin superficial fascia over pectoralis major

• A strong fibrous sheet of deep fascia between subclavius above and pectoralis minor below

• A membranous layer covering serratus anterior

• A ligament spanning the coracoid to clavicle

Answer explanation

The clavipectoral fascia is best described as a strong fibrous sheet of deep fascia located between the subclavius muscle above and the pectoralis minor muscle below, providing structural support in the shoulder region.

Superiorly, the clavipectoral fascia splits to enclose which muscle?

• Pectoralis major

• Pectoralis minor

• Subclavius

• Serratus anterior

Answer explanation

The clavipectoral fascia splits superiorly to enclose the subclavius muscle, which lies beneath the clavicle. This fascia does not enclose the pectoralis major or minor directly.

Medially, the clavipectoral fascia is thickened and extends to which structures?

• 1st and 2nd costal cartilages

• 3rd and 4th costal cartilages

• Manubrium and xiphoid

• Anterior surface of the sternum

Answer explanation

The clavipectoral fascia is thickened medially and extends to the 1st and 2nd costal cartilages, providing support and structure in the upper thoracic region.

Laterally, the clavipectoral fascia extends to which bony landmark?

• Acromion

• Coracoid process

• Greater tubercle of humerus

• Medial epicondyle

Answer explanation

The clavipectoral fascia laterally extends to the coracoid process, which serves as an important landmark for the attachment of muscles and ligaments in the shoulder region.

Inferiorly, after enclosing pectoralis minor, the clavipectoral fascia continues as which structure?

• Coracoacromial ligament

• Costocoracoid membrane

• Suspensory ligament of the axilla to join the axillary fascia

• Interclavicular ligament

Answer explanation

Inferiorly, the clavipectoral fascia continues as the suspensory ligament of the axilla, which connects to the axillary fascia. This structure supports the axilla and is crucial for its anatomy.

Which list correctly includes ONLY structures deep to the clavipectoral fascia?

• Cephalic vein, lateral pectoral nerve, acromiothoracic artery

• 1st part of axillary artery, axillary vein, cords of brachial plexus, apical lymph nodes

• Lateral pectoral nerve, axillary vein, cephalic vein

• Thoracoacromial artery, 2nd part of axillary artery, medial pectoral nerve

Answer explanation

The correct choice includes structures deep to the clavipectoral fascia: the 1st part of the axillary artery, axillary vein, cords of the brachial plexus, and apical lymph nodes, all of which are located beneath this fascia.

Which nerve is specifically noted to pierce the clavipectoral fascia?

• Lateral pectoral nerve

• Medial pectoral nerve

• Long thoracic nerve

• Axillary nerve

Answer explanation

The lateral pectoral nerve is specifically noted to pierce the clavipectoral fascia, providing motor innervation to the pectoralis major muscle. This distinguishes it from the other nerves listed.

Lymph vessels piercing the clavipectoral fascia are described as originating from which nodes and draining to which group?

• Apical to infraclavicular

• Infraclavicular to apical axillary

• Central to lateral axillary

• Parasternal to apical axillary

Answer explanation

Lymph vessels piercing the clavipectoral fascia originate from the infraclavicular nodes and drain to the apical axillary group, making 'Infraclavicular to apical axillary' the correct choice.

Which statement about the origins of pectoralis major is correct?

• Clavicular head arises from the lateral half of the clavicle

• Clavicular head arises from the anterior surface of the medial half of the clavicle

• Sternocostal head arises from the posterior surface of the sternum only

• Sternocostal head arises from the lower six costal cartilages only

Answer explanation

The correct statement is that the clavicular head arises from the anterior surface of the medial half of the clavicle. The other options incorrectly describe the origins of the pectoralis major.

Which component is NOT part of the sternocostal head origin of pectoralis major?

• Anterior surface of the sternum

• Upper six costal cartilages

• External oblique aponeurosis

• Medial half of the clavicle

Answer explanation

The medial half of the clavicle is part of the clavicular head origin of pectoralis major, not the sternocostal head. The sternocostal head originates from the anterior surface of the sternum, upper six costal cartilages, and external oblique aponeurosis.