The origin of the pectoralis major includes the clavicle, sternum, the costal cartilage of the upper ribs, and the aponeurosis of the external obliques. Pectoralis minor muscle extends from the front side of the upper ribs to the top of the shoulder blade scapula. May 21, 2015 the name of the pectoralis minor muscle describes the general location of this muscle. The pectoralis major flexes the humerus, the bone of the upper arm, picking up a baby, it draws the humerus away from the body bringing the arms up overhead in yoga, and across the body hugging yourself, in a somewhat similar way. The upper and lower fibers of pectoralis major insert to the crest of greater tubercle of the humerus. Its innervated by both medial and lateral pectoral nerves. Anterior view, right side anterior view of origin and insertion, right side. Insertion of pectoralis minor medial border and superior surface of coracoid process of scapula. The pectoralis minor is a thin, flat muscle found immediately underneath the pectoralis major. The name of the pectoralis minor muscle describes the general location of this muscle. It inserts as a flat tendon into the coracoid process of the scapula.
The base arises from the third, fourth, and fifth ribs on their upper outer surfaces. The pectoralis major muscle lies on top of the pectoralis minor muscle, which is a smaller muscle of the chest. It works together with serratus anterior muscle which protracts and rotates the scapula upwards. Pectoralis major origin, insertion, actions, innervation. Pectoralis minor muscle origin of pectoralis minor 3rd to 5th ribs near their costal cartilages. What is the difference between a pectoralis major and a. The origin of the pectoralis minor is on several of the upper ribs. Us and mr imaging of pectoralis major injuries radiographics. Pectoralis minor muscle origin, insertion, action the. The pectoralis minor is the smallest muscle of the two pectoral chest muscles. It makes up the bulk of the chest muscles in the male and lies under the breast in case of the female. Note that pectoralis major heads could be cross innervated by the lateral and medial pectoral nerve, hence the variation and range of root origins for these nerves.
It arises from the upper margins and outer surfaces of the third, fourth, and fifth ribs, near their cartilages and from the aponeuroses covering the intercostalis. The pectoralis minor is regarded as the key muscle of axilla because it crosses in front of the axillary artery and thus used to split this artery into three parts. The pectoralis minor muscle originates from the front surfaces of the third, fourth, and fifth ribs on each side of the rib cage. Lateral lip of the bicipital groove of the humerus and anterior lip of the deltoid tuberosity actions. The origin would be the anterior surfaces of ribs 3, 4, and 5. Since the pectoralis minor muscle is smaller and located underneath the pectoralis major, this muscle is thought of as the little brother muscle of the chest. This is the smaller of the two pectoral muscles, or muscles of the chest. Pectoralis minor origin, insertion, actions, injury, pain. The pectoralis minor lies underneath the pectoralis major, a thick, broad muscle that covers the upper chest. Apr 29, 2020 the pectoralis minor muscle is one of the most superficial muscles on the anterior aspect of the chest or thoracic wall, located deep only to the pectoralis major muscle. Coracoid process of the scapula 1 functions actions draws scapula forward and downward when the ribs are fixed 1. Pectoralis minor definition of pectoralis minor by. Insertion lateral lip of bicipital groove of humerus and anterior lip of deltoid tuberosity. Jan 02, 2019 theyre different muscles as stated in the collapsed answers.
Other articles where pectoralis minor is discussed. Use a tape measure to measure the linear distance between the origin and insertion of the muscle. Sternocostal headlateral manubrium and sternum, six upper costal cartilages and external oblique aponeurosis. The pectoralis minor is triangular in shape and is located under the pectoralis major, and both form the anterior wall of the axilla. Stabilizes scapula by drawing it inferiorly and anteriorly against thoracic wall innervation.
Action elevates ribs if scapula fixed, protracts scapula assists serratus anterior nerve medial pectoral nerve c8, t1 from medial cord. Its involved in other scapular movements, which ill cover later. Via a tendon to the medial aspect of the coracoid process of the scapula. The shortened, tight muscle can be easily palpated there. The insertion of the pectoralis major is at the lateral lip of the intertubercular sulcus of the humerus.
Test 1 williams et al12 stand erect with the test arm resting at the side. The pectoralis minor lies next to the rib cage deep to the pectoralis major. The origin is from the second, third and fourth or fifth ribs. Pectoralis minor with a proximal insertion origin at the superior and ventral surfaces or ribs 35 and a lateral insertion at the coracoid process of the scapula, p. Together, these muscles are often referred to simply as the pecs. Learn vocabulary, terms, and more with flashcards, games, and other study tools. I think i said pectoralis major but i meant to say minor. Its fibers run perpendicular to the pectoralis major fibers from the scapula s coracoid process to the upper ribs. Clavicular head originates from the anterior surface of the medial clavicle sternocostal head originates from the anterior surface of the sternum, the superior six costal cartilages and the aponeurosis of the external oblique muscle insertion. The pectoralis minor originates on the outer surfaces of ribs 3, 4, and 5 and from the fascia of the intercostal muscles. The pectoralis major spans the major portion of the chest.
Smaller than the pectoralis major, the pectoralis minor functions to stabilize the scapula. Anterior surfaces near the cartilages of the ribs 35 1 insertion. Toward the insertion, the muscle flattens and becomes a tendon. Aug 24, 2012 smaller than the pectoralis major, the pectoralis minor functions to stabilize the scapula. Anatomy, thorax, pectoralis major major statpearls. Understand your pectoralis minor for deeper backbends. Anterior surface of the medial half of the clavicle insertion. The word pectoralis literally means chest or breast in latin and major means big. Pectoralis major is a thick, fanshaped muscle contributing to the thoracobrachial motion. Modify this common stretch for the chest to target the pectoralis minor specifically. During aerobic activity the pectoralis minor helps to elevate the rib cage for inhalation. Anterior surfaces of the third to fifth ribs insertion.
Oct 15, 2018 pectoralis minor origin and insertion. Part or all of the tendon may transverse this process and continue into the coracoacromial ligament. While it is possible to do just by wiggling around the blunt probe and using your fingers, you should be careful not to cut or damage any muscles under the pectoralis. The muscle inserts on the coracoid process of the scapula. It is one of the four muscles of the rotator cuff, along with the supraspinatus, infraspinatus and subscapularis rotator cuff muscles act together to control the movements of the humeral head and stabilize it within the glenoid cavity of the shoulder joint, as the arm moves in. Beneath the pectoralis major is the pectoralis minor, a thin, triangular muscle. Theyre different muscles as stated in the collapsed answers.
Choose from 7 different sets of pectoralis minor flashcards on quizlet. The pectoralis minor muscle is one of the most superficial muscles on the anterior aspect of the chest or thoracic wall, located deep only to the pectoralis major muscle. It aids in drawing the shoulder forward and downward in opposition to the trapezius muscle. The apex of the triangle inserts into the medial border and upper surface of. Originates from the 3rd5th ribs, and inserts into the coracoid process of the scapula. This muscle extends from three origins on the third, fourth, and fifth ribs on each side of the ribcage to the coracoid process a small, hooklike. It helps stabilize the scapula and is the prime mover in scapular downward rotation. It is technically classified as part of the anterior axioappendicular muscle group. Injuries of the pectoralis major can also be categorized according to their location. It inserts at the coracoids process of the scapula and its innervation is via the medial pectoral nerve. Thats the origin, insertion, and the action of pectoralis minor. The muscle is the only one in the upper limb to be supplied by all five segments.
Muscle actionfunction of pectoralis minor stabilizes scapula by drawing it inferiorly and. The pectoralis minor lies, for the most part, beneath the pectoralis major, arising from the middle ribs and inserting into attaching to the scapula shoulder blade. A number of tests have been proposed to measure length in the pmi. It is one of the four muscles of the rotator cuff, along with the supraspinatus, infraspinatus and subscapularis rotator cuff muscles act together to control the movements of the humeral head and stabilize it within the glenoid cavity of the shoulder joint, as the arm moves in various.
The pectoralis minor lies underneath its larger counterpart muscle, pectoralis major. It functions to rotate the scapula, to draw it down and forward, and to raise the third, the. How to assess and stretch the pec minor ptprogress. Both of these muscles form part of the anterior wall of the axilla region. The pectoralis minor muscle is a thin, triangular muscle, situated at the upper part of the chest and beneath the pectoralis major in the human body. It is also located close in relation to the brachial plexus and both the subclavian artery and vein, which all run between the muscle and the rib cage. It is one of the anterior axioappendicular thoracoappendicular muscles, together with the pectoralis major, subclavius and serratus anterior. It makes up the bulk of the chest muscles and lies under the breast. Medial pectoral nerve c8, t1 from medial cord and lateral pectoral nerve c5, c6, c7 from lateral cord. Learn pectoralis minor with free interactive flashcards. Teres minor is a posterior muscle of the shoulder that extends between the scapula and the head of humerus. Together with other muscles of the region it produces various movements of the. Innervation to the pectoralis minor is also received from the lateral pectoral nerve, via a communicating branch known as the ansa pectoralis, which is usually.
The tendon of insertion may extend over the coracoid process to the greater tubercle. Pectoralis comes from the latin word pectus meaning breast. Patients with injuries at the muscle origin or belly, including contusions and strains, usually are treated. There are 2 heads of the pectoralis major, the clavicular and the sternocostal, which reference their area of origin12. The pectoralis major from latin pectus, meaning breast is a thick, fanshaped muscle, situated at the chest of the human body. Standing with your right side close to a wall, extend your right arm up and out behind your body, with your palm on the wall at a 45degree angle. It consists of a clavicular part and a sternal part, both converging to a flat tendon that inserts on the humerus. Medial border and superior surface of coracoid process of scapula. There is another pectoral muscle, the pectoralis minor that is a smaller triangular shaped muscle. Flexion, adduction and internal rotation of the arm at shoulder innervation. To view the pectoralis major, you must cut away a large amount of superficial muscle and connective tissue. Apr 29, 2020 teres minor is a posterior muscle of the shoulder that extends between the scapula and the head of humerus. The pectoralis majors primary functions are flexion, adduction, and internal rotation of the humerus.