L8 pectoral region .pdf

Pectoral region  Pectoral region Cutaneous innervation The skin of the pectoral region is supplied by: 1. Branches of the supraclavicular nerve 2. The ventral rami of the intercostal nerves.  MUSCLES OF THE PECRORAL REGION 1....

Pectoral region  Pectoral region Cutaneous innervation The skin of the pectoral region is supplied by: 1. Branches of the supraclavicular nerve 2. The ventral rami of the intercostal nerves.  MUSCLES OF THE PECRORAL REGION 1. Pectoralis major 2. Pectoralis minor 3. subclavius 4. Serratus anterior  1. Pectoralis major Origin: 1. Clavicular head; from the front of the medial third of the clavicle 2. Sternocostal head; from the anterior aspect of the sternum and the upper six costal cartilages Insertion: Lateral lip of bicipital groove of the humerus Action: 1. Adduction and medial rotation of the arm 2. Flexion of the arm (clavicular portion) Nerve supply. Lateral pectoral nerve, C5, 6, 7 2. Medial pectoral nerve, C8, T1  2. Pectoralis minor Origin: 3rd , 4th and 5th ribs near their costal cartilages. Insertion: Medial aspect of coracoid process of the scapula Action: Depresses point of shoulder; if the scapula is fixed, it elevates the ribs of origin Nerve supply: medial pectoral nerve, C8,T1  3. Subclavius muscle Origin: First costal cartilage Insertion: Lower surface of clavicle (subclavius groove) Action: Depresses the clavicle and steadies this bone during movements of the shoulder girdle Nerve supply: Nerve to the subclavius, from the upper trunk of the brachial plexus C5,6 Serratus anterior muscle Origin: From the outer surface of upper 8 ribs Insertion: costal aspect (Ventral aspect) of medial border and inferior angle of scapula Action: Draws the scapula forward around the thoracic wall (protrusion); rotates scapula Nerve supply: long thoracic nerve, C5,6,7  Clavipectoral Fascia The clavipectoral fascia is a strong sheet of connective tissue that is attached above to the clavicle. Below, it splits to enclose the pectoralis minor muscle and then continues downward as the suspensory ligament of the axilla and joins the fascial floor of the armpit. Clavipectoral fascia surrounds the subclavius and pectoralis minor muscles 1. Costocoracoid membrane: upper segment (medial and lateral attachments) * The clavipectoral fascia is pierced by 4 structures: - Cephalic v. - Thoracoacromial a. - Lateral Pectoral n. - Lymphatic vessels 2. Suspensory Ligament of the Axilla – (lower segment – fuses with axillary fascia at axillary floor)