What does the pectoralis do in the muscular system?
The pectoralis major extends across the upper part of the chest and is attached to a ridge at the rear of the humerus (the bone of the upper arm). Its major actions are adduction, or depression, of the arm (in opposition to the action of the deltoideus muscle) and rotation of the arm forward about the axis of the body.
What is the action of pectoralis major?
The main function of this chest muscle as a whole is the adduction and internal rotation of the arm on the shoulder joint. Acting independently, the clavicular part helps to flex the extended arm up to 90°, while the sternocostal part facilitates the extension of the flexed arm by pulling it downwards.
What type of muscle is the pecs?
The pectoralis major muscle is a large muscle in the upper chest, fanning across the chest from the shoulder to the breastbone. The two pectoralis major muscles, commonly referred to as the ‘pecs,’ are the muscles that create the bulk of the chest.
What is the major action of the pectoralis minor?
[3] Function The primary actions of this muscle include the stabilization, depression, abduction or protraction, internal rotation and downward rotation of the scapula. It elevates the ribs for deep inspiration when the pectoral girdle is fixed or elevated.
Is pectoralis major a skeletal muscle?
The pectoralis major (from Latin pectus ‘breast’) is a thick, fan-shaped or triangular convergent muscle, situated at the chest of the human body. It makes up the bulk of the chest muscles and lies under the breast….
| Pectoralis major | |
|---|---|
| FMA | 9627 |
| Anatomical terms of muscle |
Where is the pectoralis muscle?
anterior chest wall
The pectoralis major is the superior most and largest muscle of the anterior chest wall. It is a thick, fan-shaped muscle that lies underneath the breast tissue and forms the anterior wall of the axilla.
What does the pectoralis major muscle do quizlet?
What does the pectoralis major muscle do? It adducts the arm.
Where is the pectoral region?
The pectoral region is located on the anterior chest wall. It contains four muscles that exert a force on the upper limb: the pectoralis major, pectoralis minor, serratus anterior and subclavius.
What joint does the pectoralis minor move?
shoulder joint
The pectoralis minor muscle functions primarily to move the scapula both forward and downward. The scapula is one of the bones that make up the shoulder joint.
What are pectorals?
The pectoral muscles are the group of skeletal muscles that connect the upper extremities to the anterior and lateral thoracic walls. Juxtaposed with the regional fascia, these muscles are responsible for moving the upper extremities in a wide range of motion.
Where are pectorals located?
chest
Pectoral muscles (colloquially referred to as “pecs”) are the muscles that connect the front of the human chest with the bones of the upper arm and shoulder. This region contains four muscles that provide movements to the upper limbs or ribs.
What part of the body does the pectoralis major move quizlet?
1. The pectoralis major muscle, which fleshes out the anterior chest(and inserts on the humerus), is a primemover of arm flexion.
What is a pectoral region in anatomy?
The pectoral region is the anterior region of the upper chest where there are four thoracoappendicular muscles (also known as the pectoral muscles): pectoralis major. pectoralis minor. subclavius. serratus anterior.
Where does the pectoralis major attach?
humerus
Pectoralis major is a thick, fan-shaped muscle contributing to the thoracobrachial motion. It consists of a clavicular part and a sternal part, both converging to a flat tendon that inserts on the humerus.
Which of the following movements is made possible by the pectoralis major?
The pectoralis major has four actions which are primarily responsible for movement of the shoulder joint. The first action is flexion of the humerus, as in throwing a ball underhand, and in lifting a child. Secondly, it adducts the humerus, as when flapping the arms.
How the muscles pectoralis major and serratus anterior show two different ways in which muscles are named?
Explain how the muscles pectoralis major and serratus anterior show two different ways in which muscles are named. The serratus anterior is named for its relation to the bone and its origin and muscle fibers. The pectoralis major is named for its size and location in the body.
What is the pectoral girdle?
The shoulder, or pectoral, girdle is composed of the clavicles (collarbones) and the scapulae (shoulder blades). In humans the clavicles join the sternum (breastbone) medially and the scapulae laterally; the scapulae, however, are joined to the trunk only by muscles.
What are the pectoralis major and PECS?
The two pectoralis major muscles, commonly referred to as the ‘pecs,’ are the muscles that create the bulk of the chest. A developed pectoralis major is most evident in males, as the breasts of a female typically hide the pectoral muscles. A second pectoral muscle, the pectoralis minor, lies beneath the pectoralis major.
What does the pectoralis major muscle do?
The pectoralis major muscle is a powerful adductor and medial rotator of the arm, and also assists in flexion of the shoulder joint. It is also responsible for keeping the arm attached to the trunk of the body, and with the upper limb fixed in abduction the muscle is a useful accessory muscle of inspiration.
What is the shape of the pectoralis major?
Pectoralis major is a large, fan-shaped muscle. It covers much of the anterior chest wall. It is composed of three parts named for their origins, with the sternocostal head forming the bulk (~80%) of the total muscle volume 8,9:
How many fibers make up the pectoralis major muscle?
Electromyography suggests that it consists of at least six groups of muscle fibers that can be independently coordinated by the central nervous system. The pectoralis major muscle is a powerful adductor and medial rotator of the arm, and also assists in flexion of the shoulder joint.