What is the insertion of the pectoralis major muscle?
The insertion of the pectoralis major is at the lateral lip of the intertubercular sulcus of the humerus. There are 2 heads of the pectoralis major, the clavicular and the sternocostal, which reference their area of origin. The sternocostal head is described as having between 2 to 7 distinct segments.
Where is the origin and insertion of the pectoralis minor?
|Third to fifth ribs, near the costochondral junction
|Medial border and superior surface of the coracoid process of the scapula
|Pectoral branch of the thoracoacromial trunk
|Medial pectoral nerve (C8)
Where does the pectoralis major insert into?
|Lateral lip of the bicipital groove of the humerus (anteromedial proximal humerus)
|pectoral branch of the thoracoacromial trunk
|lateral pectoral nerve and medial pectoral nerve Clavicular head: C5 and C6 Sternocostal head: C7, C8 and T1
What bone does the pectoralis major originate?
There are two such muscles on each side of the sternum (breastbone) in the human body: pectoralis major and pectoralis minor. The pectoralis major, the larger and more superficial, originates at the clavicle (collarbone), the sternum, the ribs, and a tendinous extension of the external oblique abdominal muscle.
How do you stretch the pectoralis muscle?
Doorway Pectoral Stretch (Flexibility)
- Stand in an open doorway. Raise each arm up to the side, bent at 90-degree angles with palms forward.
- Slowly step forward with one foot. Feel the stretch in your shoulders and chest.
- Hold for 30 seconds. Step back and relax.
- Repeat 3 times, or as instructed.
What are the 4 pectoral muscles?
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 is the main function of the pectoralis minor muscle?
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.
In which animal pectoralis minor muscle is found?
The pectoralis minor is inserted at the coracoid process of the scapula in bonobos and humans and at the supraspinatus tendon in our common chimpanzees, which has not previously been described.
What nerve controls the pectoralis major?
The medial pectoral nerve originates from the medial cord of the brachial plexus and supplies the posterolateral parts of the sternal head of the pectoralis major as well as the pectoralis minor muscle.
Why do chest muscles get tight?
Muscle strain is a common cause of tightness in the chest. Straining of the intercostal muscles, in particular, can cause symptoms. In fact, 21 to 49 percent of all musculoskeletal chest pain comes from straining the intercostal muscles. These muscles are responsible for attaching your ribs to one another.
What is the muscle in front of your armpit called?
Subscapularis – The Armpit Muscle.
What does pectoralis major do?
The pectoralis major’s primary functions are flexion, adduction, and internal rotation of the humerus. The pectoral major may colloquially be referred to as “pecs”, “pectoral muscle” or “chest muscle” due to it being the largest and most superficial muscle in the chest area.
What is the opposing muscle of the pectoralis major?
The muscles in front of the shoulder such as pectoralis major, pectoralis minor, subscapularis become tight and contracted. While the opposing muscles such as rhomboids, middle trapezius, infarspinatus, and teres minor become weak inhibited and essentially contracted or overstretched.
Are the pectoralis major and pectoralis minor antagonistic?
The pectoralis minor and pectoralis major muscles are antagonistic to one another . If the pectoralis major is the prime muscle in flexion, the antagonistic extensor is the pectoralis minor. The extensors of the leg are the quadriceps femoris muscle group.
What is the origin and insertion of the psoas muscle?
The psoas minor muscle originates from the vertical fascicles inserted on the twelfth thoracic and first lumbar vertebrae.