Chapter 10 - Shoulder Muscles (KN 251)
What is the origin point of the Deltoid?
Anterior Head: 1/3 of clavicle Middle Head: Part of the acromiom process Posterior Head: Scapular Spine
What is the origin point(s) of Pectoralis Minor?
Anterior surfaces of ribs 3-5 (or 2-4)
What is the action of the Subscapularis Muscle?
Assists in medial rotation of the shoulder
What is the origin point(s) of Pectoralis Major?
Clavicle Body of Sternum
What is the insertion point of the Pectoralis Minor?
Coracoid Process of Scapula
Does the Spinal Accessory Nerve innervate the Trapezius muscle?
Correct
Is the innervation of Teres Major the Lower Subscapular Nerve?
Correct
What is the insertion point of the Deltoid?
Deltoid Tuberosity of humerus
True or False All four Rotator cuff muscles insert in the Greater Tubercle of the Humerus
False The only muscle that DOES NOT insert in the Greater Tubercle is Subscapularis. It inserts in the LESSER Tubercle of the Humerus
True or False Teres Major's origin point is in the SUPERIOR part of the lateral border of the scapula
False The origin point is the INFERIOR part of the lateral border
What are the main actions of the shoulder muscles?
Flexion Extension Adduction
What are the functions of the Coracobracialis?
Flexion and Adduction of the Humerus
How many muscles make up the Rotator Cuff muscles?
Four
What is the origin of the Infraspinatus muscle?
Infraspinous Fossa
What is the insertion point of the Latissimus Dorsi?
Intertubecular Groove of Humerus
What is the insertion point of the Pectoralis Major?
Intertubercular Sulcus of Humerus
What is the Axillary Nerve?
It innervates the Deltoid and Teres Minor
What is the main action of the Latissimus Dorsi?
It is a powerful adductor of the arm.
What is the primary action of the Deltoid?
It is the primary abductor of the arm
What is the origin of the Teres Minor muscle?
Lateral Border of Scapula
What is the action of the Infraspinatus Muscle AND the Teres Minor Muscle?
Lateral rotation of arm
What three muscles are innervated by the Dorsal Scapular Nerve?
Levator Scapulae Rhomboid Major Rhomboid Minor
What is the insertion of the Rhomboid Major?
Medial Border of the Scapula
What is the innervation of Coracobracialis?
Musculocutaneous Nerve
How many muscles cross the shoulder joint?
Nine
What are the origin points of the Trapezius muscle?
Occipital Bone + ALL Cervical and Thoracic Vertebrae. It makes up the upper back muscle
What is the origin point AND insertion point of the Coracobracialis muscle?
Origin: Coracoid Process of Scapula Insertion: Body of Humerus
What three muscles are the PRIME MOVERS of the arm?
Pectoralis Major Latissimus Dorsi Deltoid
What is the main actions of Pectoralis Minor?
Pulls scapula forward and downward.
What muscles make up the rotator cuff?
SITS: Subscapularis, Infraspinatus, Teres minor, & Supraspinatus
What is the action of the Supraspinatus Muscle?
Shoulder Abduction and assists the Deltoid
What is the main actions of Pectoralis Major?
Shoulder Flexion and Abduction
What are the origin points of the Rhomboid Minor?
Spines of C7-T1
What are the origin points of the Rhomboid Major?
Spines of T2-T5
What is the origin of the Subscapularis muscle?
Subscapular Fossa
What is the insertion of the Levator Scapulae?
Superior Vertebral Border of Scapula
What nerve innervates both the Infraspinatus and Supraspinatus Muscle?
Suprascapular Nerve
What is the origin of the Supraspinatus muscle?
Supraspinous Fossa
What is the origin of Latissimus Dorsi?
T7-L5 vertebrae of their spinous processes. This muscle covers the distal 1/2 of back
What muscle shares the intertubecular sulcus insertion point like Pectoralis Major?
Teres Major
What nerve innervates the Latissimus Dorsi?
Thoracodorsal nerve
How many heads does the Deltoid muscle have?
Three Anterior, Middle, Posterior
How many main insertion points does the Trapezius have?
Three Clavicle + Acromion and Scapula Spine
What is the origin of the Levator Scapulae?
Transverse Processes of C1-C5
What muscles make up the shoulder region?
Trapezius Latissimus dorsi Levator scapulae Rhomboid major Rhomboid minor Deltoid Teres major Pectoralis major Pectoralis minor
True or False Pectoralis Minor is located deep to Pectoralis Major
True
True or False Teres Major is a powerful adductor muscle
True
True or False The Rotator Cuff Muscles all have origins somewhere on the scapula
True
True or False The Subscapularis Muscle is innervated by BOTH the Upper and Lower Subscapular Nerve
True
True or False: Pectoralis Major and Pectoralis Minor share the same innervations
True Medial and Lateral Pectoral Nerves
True or False The Levator Scapulae, Rhomboid Major, and Rhomboid Minor share the same action
True They elevate and adduct the scapula
What is the insertion of the Rhomboid Minor?
Vertebral border of scapula
Does the Trapezius act on the shoulder joint?
Yes. The muscle extends the neck and adducts scapula