Pectoral region Flashcards
Where is the pectoral region located?
The anterior chest wall
How many muscles make up the pectoral region?
4
List the muscles that comprise the pectoral region
Pectoralis Major
Pectoralis Minor
Serratus Anterior
Subclavius
Which muscle in the pectoral region is most superficial?
Pectoralis Major
How many heads does the pectoralis major have?
Two, they fan out in opposite directions.
What is the function of the pectoralis major?
Adducts and medially rotates the upper limb.
Draw a the scapular antero-inferiorily.
The clavicle head acts to flex the upper limb.
What nerve innervates the pectoralis major?
Lateral and medial pectoral nerves
The intertubercular sulcus of humerus is the site of insertion of what part of what muscle?
Distal attachments of both heads of the pectoralis major.
Which part of the pectoralis major originates from the sternum, the 6 superior costal cartilages and the aponeurosis of the external oblique muscles?
Sternocostal head
What’s the origin of the clavicle head of the pectoralis major?
Anterior surface of the medial clavicle
The anterior wall of the Axilla is comprised of which two muscles?
Pectoralis major and minor
Which is muscle is deeper the pectoralis major or minor?
Minor
Where does the pectoralis minor insert?
3rd-5th rib origin
Cor acid process of the scapula.
What’s the function of the pectoralis minor?
Stabilise the scapula by drawing it antero-inferiorly against the thoracic wall
What nerve innervates the pectoralis minor?
Medical pectoral nerve
What muscle rotates the scapula allowing the arm to be raised over 90 degrees and holds the scapula against the rib cage?
Serratus anterior
Which muscle originates from lateral aspects of ribs 1-8 and attach at the rib facing medial scapula border?
Serratus Anterior
What muscle in the pectoral region is innervates by the long thoracic nerve?
Serratus anterior
Describe the Subclavius.
A small muscle located just under the clavicle. The uncle runs horizontally and helps protect the neurovascular structures just deep to it.
The muscle is innervates by the nerve to Subclavius and anchors and depressed the clavicle.
Attaches at the junction of the first rib and costal cartilage and runs t the inferior surface of the middle third of the clavicle.
What can a winged scapula indicate?
The scapula sticks out as its no longer held to the rib cage. This indicates the serratus anterior is defective which could be due to damaged thoracic nerve.
What is the most common cause of thoracic nerve damage?
Traction injury, pulling the arm so it’s stretched and pulled violently.
