Pectoral Region

Pectoris Minor origin:

3, 4, 5 ribs, and the deep fascia that covers the intervening intercostal spaces.

The medial border and the inferior angle of the scapula are undully prominent. A deformity known as

A winged scapula

What are the actions of the Pectorals Major?

Acting as a whole, the muscle adducts and medially rotates the shoulder joint(arm)

Serrates Anterior origin:

By eight digitations from the upper eight ribs and from the fascia covering the intervening intercostal spaces.

Situated deep to pectorals major, its upper part splits to enclose the subclavius muscle, inferiorly it splits to enclose the pectorals minor muscle, and continues as the suspensory ligament of the axilla, which attaches to the dome of the axillary fascia.

Clavipectoral fascia

An internervous plane commonly used in the surgical approach to the shoulder joint

Deltopectoral groove

Pectoralis Minor performs the action of:

Depresses the tip of the shoulder; assists serrates anterior muscle in drawing the scapula forward (protraction)

Subclavius Origin:

From the rib at the costochondral junction.

Serratus Anterior Nerve supply:

Long thoracic nerve, which is derived from the roots of the brachial plexus.

Pectoralis Minor insertion:

Medial border and upper surface of the coracoid process

Pectoralis Minor Nerve supply:

Medial pectoral nerve

Subclavius Nerve supply:

Nerve to subclavius from the upper trunk of the brachial plexus.

Subclavius Insertion:

Onto a groove on the inferior surface of the middle third of the clavicle.

Pectoral fascia encloses what muscle?

Pectoralis major

Subclavius Action:

Pulls clavicle medially to stabilize sternoclavicular joint during movements of the shoulder joint.

Serratus Anterior Action:

Pulls scapula forwards around the chest wall to protract the upper limb (pushing and punching movements) (when the fibers inserted into the inferior angle of the scapula contract, they pull the inferior angle and rotate the scapula so that the glenoid cavity is turned upwards (in abduction of the arm) The tonic contraction of the muscle keeps the costal surface of the scapula closely opposed to the thoracic wall.

Between the breast and pectoral fascia is loose connective tissue plane known as

Retromammary space or bursa

Breast Mammary Gland attachment:

Strands of fibrous tissue, the suspensor ligament of Cooper

What nerve is exceptional in that it courses on the superficial aspect of the serrates anterior, thus making it vulnerable to injury?

The Long thoracic nerve

A modified sweat gland that lies in the subcutaneous tissue of the anterior thoracic wall.

The breast

Superiorly under the clavicle, the two muscles diverge slightly to form

The clavipectoral triangle

Serratus Anterior Insertion:

The muscle forms a flattened sheet, which passes posteriorly around the thoracic wall to insert on the costal surface of the medial border of the scapula

The sternocostal head arises from ___________ ____________ of the manubrium and body of the sternum, and the adjacent costal cartilages

anterior surface

What is the insertion of the Pectorals Major?

by a bilaminar tendon

Pectorals Major nerve supply:

by medial and lateral pectoral nerves.

A well-developed band formed from the clavipectoral fascia, it extends from the first costochondral junction to the coracoid process

costocoracoid ligament

Groove which contains the cephalic vein

deltopectoral groove

Sternocostal head does what action to the arm?

extends the flexed arm

The clavicular head does what action to the arm?

flexes

Pertaining to the Pectorals Major, The clavicular head arises from what part of the clavicle

medial half

The base of the breast extends from

the steal edge to the anterior axillary line, and from the 2nd to 6th ribs. It overlies pectorals major and serrates anterior muscles.