The Muscular Sysem - Muscles of the Body: Upper Body Musculature Flashcards
Into what three parts is the pectoralis major divided into?
The clavicular part, the sternocostal part, and the abdominal part
Where does the pectoralis major originate from?
Clavicular part: anterior surface of medial half of clavicle.
Sternocostal part: anterior surface of sternum, Costal cartilages of ribs 1-6.
Abdominal part: Anterior layer of the rectus sheath.
Where does the pectoralis major insert?
Crest of greater tubercle of humerus.
What are the actions of the pectoralis major muscle?
Arm adduction, arm internal rotation, arm flexion, and extension.
Where does the pectoralis minor originate from?
Anterior surface, costal cartilages of ribs 3-5
Where does the pectoralis minor insert?
Medial border and coracoid process of scapula.
What are the actions of the pectoralis minor?
To draw the scapula anteroinferiorly, and stabilizes scapula on the thoracic wall.
Where does the latissimus dorsi muscle originate from?
The inferior angle of the scapula, spinous processes of T7 -T12, inferior 3rd or 4th ribs, posterior third of the iliac crest, thoracolumbar fascia
Where does the latissimus dorsi insert?
Intertubercular groove of the humerus, between pectoralis major and teres major muscles
What are the functions of the latissimus dorsi muscle?
primarily responsible for adduction, extension, horizontal abduction, and internal rotation of the shoulder joint. It also assists in stabilizing the LPHC.
Where does the trapezius muscle insert?
Spine of the scapula, acromion, & lateral third of the clavicle.
Where does the trapezius muscle originate from?
Spinous processes of C7 - T12 vertebra, Nuchal ligament, Superior nuchal line, & occipital ptuberance
What are the functions of the trapezius muscle?
Lateral flexion of the neck, cervical extension, scapular elevation, rotation, depression, retraction.
Where does the serratus anterior muscle originate from?
Lateral surface of 1 - 8/9 ribs
Where does the serratus anterior muscle insert?
Superior angle, medial border, & inferior angle of the scapula
What are the actions of the serratus anterior muscle?
Its function is to protract, stabilize, and provide upward rotation of the scapula.
Where does the rhomboid major originate from?
Spinous process of vertebrae T2-T5
Where does the rhomboid major insert?
Medial border of scapula (from inferior angle to root of spine of scapula)
Where does the rhomboid minor originate from?
Nuchal ligament, Spinous processes of vertebrae C7 - T1
Where does the rhomboid minor insert?
Root (medial end) of the scapular spine
What are the actions of the rhomboid muscles?
Stabilizes, retracts, and rotates the scapula.
Where does the levator scapulae originate from?
Transverse processes of vertebrae C1-C4
Where does the levator scapulae insert?
Upper medial border of scapula
What are the actions of the levator scapulae?
Assists in scapular retraction, lateral flexion, and neck extension.
The deltoid consists of what three heads?
Anterior, lateral, and posterior heads
Where does the anterior deltiod head originate from?
the superior surface and the anterior border of the lateral third of the clavicle.
Where does the anterior deltiod head originate from?
The superior surface and the anterior border of the lateral third of the clavicle.
Where does the lateral deltoid head originate from?
From the lateral margin and superior surface of the acromion of the scapula.
Where does the posterior deltoid head originate from
From the lateral 1/3 of the spine of scapula, on the crest.
Where does all three heads of the deltoid muscle insert?
Deltoid tuberosity of humerus
What are the actions of the deltoid muscle?
Shoulder flexion, internal rotation of the humerus, arm abduction, shoulder extension, and also provides dynamic support the glenohumeral joint.
What are the actions of the rotator cuff muscles?
To provide mobility and stability to the glenohumeral joint. The rhomboids and trapezius provide mobility and stability to the scapula.
Where does the infraspinatus muscle originate from?
Infraspinous fossa of scapula
Where does the infraspinatus insert?
Greater tubercle of humerus
What are the actions of the infraspinatus muscle?
Arm external rotation and stabilizes humeral head in the glenoid cavity.
Where does the teres minor muscle originate from?
Lateral border of scapula
Where does the teres minor muscle insert?
The posterior surface of the greater tubercle of the humerus.
What are the actions of the teres minor muscle?
External rotation or the arm, arm adduction and stabilizes humeral head in glenoid cavity.
Where does the subscapularis muscle originate from?
Subscapular fossa of scapula
Where does the subscapularis muscle insert?
Lesser tubercle of humerus
What are the functions of the subscapularis muscle
Internal rotation of the arm, and stabilizes the humeral head in the glenoid cavity
Where does the supraspinatus originate from?
Supraspinous fossa of the scapula.
Where does the supraspinatus insert?
The greater tubercle of the humerus.
What are the actions of the supraspinatus
Abduction of the arm and stabilization of the humeral head in the glenoid cavity
Where do the short head and the long head of the biceps brachii originate from?
Short head originates from Coracoid process of the scapula.
Long head originates from the Supraglenoid tubercle of the scapula.
Where does the bicep brachii insert?
Radial tuberosity of the radius and deep fascia of forearm
What are the actions of the bicep brachii?
Flexion and supination of the forearm at the elbow joint
The three heads of the tricep brachii are called….
Long head, medial head, and lateral head
Where does the long head of the tricep brachii originate from?
Infraglenoid tubercle of the scapula
Where does the medial head of the tricep brachii originate from?
posterior surface of the humerus (below to radial groove)
Where does the lateral head of the tricep brachii originate from?
posterior surface of the humerus (above the radial groove)
Where does the tricep brachii insert?
Olecranon of ulna and fascia of forearm
Where does the brachioradialis originate from?
Lateral supracondylar ridge of humerus, lateral intermuscular septum of arm
Where does the brachioradialis insert?
(Proximal to) styloid process of the radius
What are the actions of the brachioradialis muscle?
Forearm flexion (when semi pronated)
Where does the trapezius muscle insert?
Spine of the scapula, acromion, & lateral third of the clavicle.
