Logan Steele
The pectoralis muscle is a vital component of the upper body musculature. The pectoralis major and pectoralis minor muscles play a crucial role in various movements, including pushing, lifting, and stabilising the shoulders and arms. The pectoralis major constitutes the bulk of the chest muscles, lying underneath the breast, and is innervated by the lateral and medial pectoral nerves. Acting together with the latissimus dorsi muscle, the pectoralis major pulls the trunk forwards or upwards when its humeral attachment is fixed. This action is important in activities such as climbing.
| Characteristics | Values |
|---|---|
| Name | Pectoralis major muscle |
| Other names | Pecs, pectoral muscle, chest muscle |
| Description | Thick, fan-shaped or triangular convergent muscle of the human chest |
| Location | Anterior chest wall |
| Covering | In males, deep layer of fascia, subcutaneous tissue and the adjacent skin; in females, the breast |
| Innervation | Lateral and medial pectoral nerves |
| Arterial supply | Pectoral branches of thoracoacromial artery and the perforating branches of internal thoracic artery |
| Function | Adduction and internal rotation of the humerus at the shoulder joint |
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What You'll Learn
- The pectoralis major muscle is the largest and most superficial muscle in the chest area
- The pectoralis major muscle is innervated by the lateral and medial pectoral nerves
- The pectoralis major muscle is vascularised by the pectoral branches of the thoracoacromial artery
- The pectoralis major muscle is responsible for flexion, adduction, and internal rotation of the humerus
- The pectoralis major muscle is covered by the breast in females and a deep layer of fascia, subcutaneous tissue and the adjacent skin in males
The pectoralis major muscle is the largest and most superficial muscle in the chest area
The pectoralis major is innervated by the lateral and medial pectoral nerves (root value C5-T1), which stem from the brachial plexus. It is vascularised by the pectoral branches of the thoracoacromial artery and the perforating branches of the internal thoracic artery. The muscle receives double motor innervation from the medial pectoral nerve and the lateral pectoral nerve.
The primary functions of the pectoralis major are flexion, adduction, and internal rotation of the humerus. When the arm is in the anatomical position, the pectoralis major acts as a strong adductor and internal rotator of the humerus at the shoulder joint. Acting independently, the clavicular portion of the muscle flexes the humerus up to 90 degrees in a horizontal plane. The sternocostal portion of the muscle can produce the antagonistic movement and extend the humerus back to the anatomical position.
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The pectoralis major muscle is innervated by the lateral and medial pectoral nerves
The pectoralis major muscle is the largest and most superficial muscle in the chest area. Colloquially, it is referred to as the 'pecs', 'pectoral muscle' or 'chest muscle'. It makes up the bulk of the chest muscles and lies under the breast. The pectoralis major muscle is innervated by the lateral and medial pectoral nerves (root value C5-T1), which stem from the brachial plexus.
The pectoralis major arises from parts of the clavicle and sternum, costal cartilages of the true ribs, and the aponeurosis of the abdominal external oblique muscle. It receives double motor innervation from the medial pectoral nerve and the lateral pectoral nerve. The primary functions of the pectoralis major are flexion, adduction, and internal rotation of the humerus. When the arm is in the anatomical position, the pectoralis major acts as a strong adductor and internal rotator of the humerus at the shoulder joint.
The pectoralis major is vascularised by the pectoral branches of the thoracoacromial artery and the perforating branches of the internal thoracic artery. The deep surface of the muscle covers the pectoralis minor and serratus anterior muscles and the anterior surface of the upper six ribs. The triangular depression between the pectoralis major muscle, deltoid muscle and clavicle is called the infraclavicular fossa (Mohrenheim's fossa). This serves as an important landmark in surgical procedures on the subclavian artery.
The pectoral muscles are the group of skeletal muscles that connect the upper extremities to the anterior and lateral thoracic walls. These muscles are responsible for moving the upper extremities in a wide range of motions, including flexion, adduction, and internal rotation of the humerus, stabilisation of the scapula, as well as elevating and depressing the bones of the thorax.
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The pectoralis major muscle is vascularised by the pectoral branches of the thoracoacromial artery
The pectoralis major muscle is the largest and most superficial muscle in the chest area. It is a thick, fan-shaped or triangular convergent muscle that makes up the bulk of the chest muscles, lying underneath the breast. The pectoralis major muscle is vascularised by the pectoral branches of the thoracoacromial artery, which is the first branch of the axillary artery. The thoracoacromial artery arises from the subclavian artery deep to the clavicle and enters the underside of the pectoralis major muscle at about the midpoint of the clavicle. The pectoral branch of the thoracoacromial artery provides the main vascular supply to the pectoralis major muscle once elevated. It courses obliquely and parallel to a line between the acromion process and xiphoid process. The thoracoacromial artery is one of four main branches, the others being the deltoid, acromial, and clavicular branches. The pectoralis major muscle is also vascularised by the perforating branches of the internal thoracic artery.
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The pectoralis major muscle is responsible for flexion, adduction, and internal rotation of the humerus
The pectoralis major muscle is the largest and most superficial muscle in the chest area. Colloquially, it is referred to as the 'pecs', 'pectoral muscle' or 'chest muscle'. It is a thick, fan-shaped or triangular convergent muscle that makes up the bulk of the chest muscles and lies under the breast. The pectoralis major arises from parts of the clavicle and sternum, costal cartilages of the true ribs, and the aponeurosis of the abdominal external oblique muscle. It receives double motor innervation from the medial pectoral nerve and the lateral pectoral nerve. The pectoralis major's primary functions are flexion, adduction, and internal rotation of the humerus. When the arm is in the anatomical position, the pectoralis major acts as a strong adductor and internal rotator of the humerus at the shoulder joint. Acting independently, the clavicular portion of the muscle flexes the humerus up to 90 degrees in a horizontal plane. The sternocostal portion of the muscle can produce the antagonistic movement and extend the humerus back to the anatomical position.
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The pectoralis major muscle is covered by the breast in females and a deep layer of fascia, subcutaneous tissue and the adjacent skin in males
The pectoralis major muscle is the largest and most superficial muscle in the chest area. It is a thick, fan-shaped or triangular convergent muscle that makes up the bulk of the chest muscles. The pectoralis major muscle is covered by the breast in females and a deep layer of fascia, subcutaneous tissue and the adjacent skin in males.
The pectoralis major muscle is innervated by the lateral and medial pectoral nerves (root value C5-T1), which stem from the brachial plexus. It is vascularized by the pectoral branches of the thoracoacromial artery and the perforating branches of the internal thoracic artery. The primary functions of the pectoralis major muscle are flexion, adduction, and internal rotation of the humerus. It also acts as a strong adductor and internal rotator of the humerus at the shoulder joint.
The pectoralis major muscle arises from parts of the clavicle and sternum, costal cartilages of the true ribs, and the aponeurosis of the abdominal external oblique muscle. It inserts onto the lateral lip of the bicipital groove. Beneath the pectoralis major is the pectoralis minor muscle. The deep surface of the pectoralis major muscle covers the pectoralis minor and serratus anterior muscles and the anterior surface of the upper six ribs.
The triangular depression between the pectoralis major muscle, deltoid muscle and clavicle is called the infraclavicular fossa (Mohrenheim’s fossa). This serves as an important landmark in surgical procedures on the subclavian artery.
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Frequently asked questions
The pectoralis major muscle is the largest and most superficial muscle in the chest area. It is a thick, fan-shaped or triangular convergent muscle that makes up the bulk of the chest muscles. It lies under the breast in females and is covered by a deep layer of fascia, subcutaneous tissue and the adjacent skin in males.
The pectoralis major muscle is responsible for moving the upper extremities in a wide range of motion. This includes flexion, adduction, and internal rotation of the humerus, stabilisation of the scapula, as well as elevating and depressing the bones of the thorax.
The pectoralis major muscle is connected to the upper extremities and the anterior and lateral thoracic walls. It arises from the clavicle, sternum, costal cartilages of the true ribs, and the aponeurosis of the abdominal external oblique muscle.
