China
Africa
Explore chapters and articles related to this topic
Upper Limb
Published in Rui Diogo, Drew M. Noden, Christopher M. Smith, Julia Molnar, Julia C. Boughner, Claudia Barrocas, Joana Bruno, Understanding Human Anatomy and Pathology, 2018
Rui Diogo, Drew M. Noden, Christopher M. Smith, Julia Molnar, Julia C. Boughner, Claudia Barrocas, Joana Bruno
The pectoralis major and pectoralis minor have similar evolutionary and developmental origins, being innervated by the lateral pectoral nerve and the medial pectoral nerve. Pectoralis major, being larger, is innervated by both nerves, while the smaller pectoralis minor is innervated only by the medial pectoral nerve. The pectoralis major has a clavicular head, a sternocostal head, and an abdominal head. In anatomical position, the pectoralis major lies mainly anterior and medial to its insertion point onto the humerus, so its contraction adducts and flexes the arm. As its insertion is onto the lateral lip of the intertubercular groove, on the anterior surface of the humerus, it also medially (internally) rotates the arm. Because the pectoralis minor originates from ribs 3-5 and runs superiorly and posteriorly to insert onto the coracoid process of the scapula, its contraction causes the protraction and depression of the scapula. The deep fascia on the surface of the pectoralis major is called pectoral fascia, and it is continuous with the axillary fascia. Between the pectoralis major and the deltoid lies the deltopectoral triangle and the cephalic vein, which pierces the clavipectoral fascia and passes through the costocoracoid membrane (Plate 4.5b).
Pectoral Region and Breast
Published in Gene L. Colborn, David B. Lause, Musculoskeletal Anatomy, 2009
Gene L. Colborn, David B. Lause
The medial pectoral nerve is so named because it arises from the medial cord of the brachial plexus, to be described later. The lateral pectoral nerve arises from the lateral cord of the brachial plexus. Because of a communication between the lateral and medial pectoral nerves after arising from the plexus, each nerve probably contributes to the innervation of both the pectoralis major and minor. Damage to the lateral pectoral nerve may selectively paralyze the clavicular part of the pectoralis major.
Role of Intraoperative Nerve Monitoring in Postoperative Muscle and Nerve Function of Patients Undergoing Modified Radical Mastectomy
Published in Journal of Investigative Surgery, 2021
Serhat Tokgöz, Ebru Karaca Umay, Kerim Bora Yilmaz, Muzaffer Akkoca, Melih Akinci, Cem Azili, Mehmet Saydam, Yasin Ucar, Şener Balas
Radical mastectomy, which was long performed in breast cancer surgery, was replaced by modified radical mastectomy (MRM) in the 1970s. Breast-conserving surgery and oncoplastic surgical treatment protocols adopted in recent years have gained importance in the treatment of breast cancer [1, 2]. Despite these improvements in breast cancer treatment, MRM remains an important surgical treatment protocol [3]. The most common early complications of MRM are seroma formation, surgical site infection, flap necrosis, hematoma, and other major complications that are more important and permanent including nerve injuries, shoulder and arm impairments, and lymphedema [4, 5]. Problems related to nerve injury in patients undergoing axillary dissection are common in clinical practice. Radiotherapy may also cause nerve and muscle injuries. During MRM, there is a risk of injury to four nerves with motor functions: lateral pectoral nerve (LPN), medial pectoral nerve (MPN), thoracic longus nerve (TLN), and thoracodorsal nerve (TDN). The incidence of nerve injury related to breast cancer surgery is often unrecognized and underdiagnosed if specific physical examination and tests are not employed. No study to date has shown the incidence of injury of the MPN, LPN, and TDN nerves in breast cancer surgery in the literature; however, the incidence of TLN injury is reportedly 0.6–74.7% [6].
Everything pectoralis major: from repair to transfer
Published in The Physician and Sportsmedicine, 2020
Kamali Thompson, Young Kwon, Evan Flatow, Laith Jazrawi, Eric Strauss, Michael Alaia
The sternocostal head is the larger of the two muscles, making up 80% of the entire muscle volume and is composed of seven overlapping segments [3,27,32] (Figure 1). The sternocostal head originates from the second to sixth rib and the costal margin of the sternum with the fibers running upward and laterally. The inferior fibers of the pectoralis major are innervated by the medial pectoral nerve (C8-T1), which exits the medial cord of the brachial plexus, travels with the lateral thoracic artery to pierce the pectoralis minor at the midclavicular line and enters the pectoralis major at a mean of 11.0 cm medial to the humeral insertion (95% confidence interval 8.6–15.3 cm) and 2 cm proximal to the inferior edge [4,20,30]. Its’ primary role is the forward elevation of the humerus, as well as internal rotation, horizontal adduction, and extension. Tendons from both muscular heads converge laterally and insert on to the lateral lip of the bicipital groove of the humerus and the anterior lip of the deltoid tuberosity [30]. The crossing of the tendons occurs as the inferior sternocostal head rotates 180° transforming it into the posterior lamina, while the clavicular head becomes the anterior lamina [33].