pectoralis major


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Related to pectoralis major: latissimus dorsi, pectoralis minor

pectoralis major

[pek′tərā′lis, pek′tərəlis′]
Etymology: L, pectus, breast
a large muscle of the upper chest wall that acts on the joint of the shoulder. Thick and fan-shaped, it arises from the clavicle, the sternum, the cartilages of the second to the sixth ribs, and the aponeurosis of the obliquus externus abdominis. It serves to flex, adduct, and medially rotate the arm in the shoulder joint.
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Pectoralis major

pectoralis major

A large triangular muscle that extends from the sternum to the humerus and functions to flex, horizontally adduct, and internally rotate the arm, and aids in chest expansion when the upper extremities are stabilized.
See also: pectoralis
References in periodicals archive ?
As shown in Figure 6, even at the beginning of the 25-second period, muscle activity was close to 80% for the biceps and triceps muscle as well as the pectoralis major muscles.
While a medical student at Guy's Hospital, London, he dissected a male cadaver which lacked the sternocostal head of the pectoralis major and the pectoralis minor, while the serratus anterior, the external oblique, and the muscles of the left arm were hypoplastic.
In upper cross syndrome, the tight muscles usually are the upper trapezius (located between shoulder and neck), neck extensors, sternocleidomastoid (large muscle located in front of the neck), pectoralis major and levator scapulae (running from neck to shoulder blade).
Then there are the pectoralis major muscles in the chest.
She suggests specific workouts for the pectoralis major (chest), rotator cuff (shoulder) and scapular stabilizers (rhomboids, latissimus dorsi, and trapezius).
Pectoralis major -- adducts, flexes, extends, and medially rotates the arm.
Patient and control pectoralis major muscle and cardiac muscle (10 g each) were fixed in 200 mL/L formalin for 15 h at room temperature.
Females tend to utilize most those muscles involved in extension of the forearm (brachialis), internal rotation, abduction and adduction, moving the arm laterally and horizontally away from the chest and back, drawing the arm down to the side and towards the midline of the body (deltoid, teres major, pectoralis major in conjunction with upper fibres of the trapezius).
At least one exercise for each of the major muscles (biceps, triceps, pectoralis major, latissimus dorsi, deltoids, abdominals, low back, quadriceps, and hamstrings) should be performed each day.
Although the abdominal muscles are flaccid in quadriplegics, expiration is aided by the contraction of the clavicular portion of the pectoralis major muscle and the cranial portion of the serratus anterior muscle.
During each of the exercises, electromyography (EMG) electrodes monitored muscle activation of the pectoralis major muscles.
Altogether, prolonged postmortem duration adversely affects mRNA integrity of genes associated with quality of chicken pectoralis major muscle.