pectoralis major

(noun)

A large, fan-shaped muscle of the chest.

Related Terms

Examples of pectoralis major in the following topics:

  • Clavicle

    • At the medial end of the shaft the pectoralis major originates from the anterior surface, the posterior surface gives origin to the sternohyoid muscle and the superior surface the sternocleidomastoid muscle.
    • Muscle attachment sites (pectoralis major, subclavius muscle, deltoid, and sterno-hyoid) are highlighted.

  • Muscles of the Shoulder

    • Pectoralis Major – The pectoralis major is a large, fan-shaped muscle covering the chest.
    • Pectoralis Minor – The pectoralis minor muscle is smaller and lies beneath the pectoralis major.
    • Produced by the biceps brachii (both heads), pectoralis major, anterior deltoid, and corocobrachialis.
    • Produced by contraction of pectoralis major, latissimus dorsi, and teres major.
    • Produced by contraction of subscapularis, pectoralis major, latissimus dorsi, teres major, and anterior deltoid.

  • Anterior Muscles

    • Pectoralis Major – The pectoralis major is a fan-shaped muscle covering the chest and comprised of clavicular and sternocostal regions.
    • Pectoralis Minor – The smaller pectoralis minor muscle lies beneath the pectoralis major.
    • Attachments – The pectoralis minor originates from the third to fifth ribs and attaches to the scapula.

  • How Skeletal Muscles Are Named

    • The pectoralis major found in the chest is an example of a convergent muscle, and is responsible for flexing the upper arm.

  • Intercostal Nerves

    • Near the sternum, they cross in front of the internal mammary artery and transversus thoracis muscle, pierce the intercostales interni, the anterior intercostal membranes, and pectoralis major, and supply the integument of the front of the thorax and over the mamma, forming the anterior cutaneous branches of the thorax.

  • Mammary Glands

    • Pectoralis muscles 3.

  • Arteries of the Pelvis and Lower Limbs

    • The abdominal aorta divides into the major arteries of the leg: the femoral, popliteal, tibial, dorsal foot, plantar, and fibular arteries.
    • The posterior trunk gives rise to arteries that supply the posterior pelvic wall and the gluteal region, including the iliolumbar artery that supplies the psoas major muscle, the lateral sacral arteries, and the superior gluteal artery.

  • The Posterior Pituitary

    • The pars nervosa, also called the neural lobe or posterior lobe, constitutes the majority of the posterior pituitary and is the storage site of oxytocin and vasopressin.
    • Antidiuretic hormone (ADH, also known as vasopressin), the majority of which is released from the supraoptic nucleus in the hypothalamus.

  • Burns

    • Burns are also classified as major or minor depending on a combination of factors including age, thickness of burns, surface area of the body involved, and the presence of inhalation injury.
    • The majority of these fatalities occur either at the scene or on the way to hospital.
    • Infection is a major complication of burns.

  • Transport of Hormones

    • Once within the circulatory system a small proportion of hormones circulate freely, however the majority are bound with a transport protein.
    • The major endocrine glands for men and women (male left, female on the right): 1.