Upper Limb Muscular System Flashcards
What action does a muscle crossing on the anterior side of a joint produce?
Flexion
What action does a muscle crossing on the posterior side of a joint produce?
Extension
What action does a muscle crossing on the lateral side of a joint produce?
Abduction
What action does a muscle crossing on the medial side of a joint produce?
Adduction
Name three muscles in the anterior compartment that move and stabilize the shoulder.
- Subclavius
- Pectoralis minor
- Serratus anterior
What is the function of the Subclavius muscle?
Stabilizes the pectoral girdle
What action does the Pectoralis minor muscle perform?
Abducts the scapula
What is the ‘boxer’s muscle’?
Serratus anterior
Which muscles are involved in moving and stabilizing the shoulder in the posterior compartment?
- Trapezius
- Rhomboids major and minor
- Levator scapulae
What is the primary action of the middle fibers of the Trapezius muscle?
Adducts and stabilizes the scapula
What is the role of the Rhomboids major and minor muscles?
Adduct the scapula
What is the function of the Levator scapulae muscle?
Elevates the scapula
What are the four muscles collectively known as the rotator cuff muscles?
- Supraspinatus
- Infraspinatus
- Teres minor
- Subscapularis
What is the primary role of the rotator cuff muscles?
Reinforce the shoulder joint
What muscle is the prime mover for shoulder flexion?
Pectoralis major
What action does the Coracobrachialis muscle perform?
Flexes and adducts the shoulder joint
What is the prime mover for shoulder extension?
Latissimus dorsi
What muscles are antagonistic to shoulder abduction?
- Pectoralis major
- Latissimus dorsi
- Teres major
What initiates the first 10° of arm abduction?
Supraspinatus
Which muscle becomes the prime mover for shoulder abduction after the initial 10°?
Deltoid
Where are adductor muscles located relative to a joint?
On the medial side of a joint
Name the three adductor muscles of the shoulder.
- Pectoralis major
- Latissimus dorsi
- Teres major
What is the action of shoulder flexion?
Lifting the humerus in an anterior direction
Which muscles contribute to shoulder flexion?
- Pectoralis major
- Anterior fibres of deltoid
- Coracobrachialis
- Biceps brachii
What results from contraction of the latissimus dorsi?
Shoulder extension
What occurs during lateral or external rotation of the shoulder joint?
The palm faces forward
Which muscles are responsible for lateral rotation of the shoulder joint?
- Infraspinatus
- Teres minor
- Posterior fibres of deltoid
What is the action of medial or internal rotation of the shoulder joint?
The palm faces downwards
Which muscles are involved in medial rotation of the shoulder joint?
- Subscapularis
- Pectoralis major
- Latissimus dorsi
- Anterior fibres of deltoid
Which muscle is capable of flexing, extending, and abducting the arm?
Deltoid
List the muscles mentioned in the summary slide for Topic 2.3a.
- Pectoralis major
- Coracobrachialis
- Serratus anterior
- Latissimus dorsi
- Teres major
- Teres minor
- Supraspinatus
- Infraspinatus
- Deltoid
