Shoulder,Arm Flashcards
This muscle forms the shoulder’s rounded contour, being thick and spread out anteroposteriorly
Deltoid muscle
When you remove the Deltoid muscle you will find the
Supraspinatus- posteriorly
infraspinatus- posteriorly
Teres major and minor-posteriorly
subscapularis- anteriorly
The shoulder joint is a ball and socket joint formed by
the head of the humerus and the glenoid cavity
the glenoid cavity is part of
the scapula
Another word for the shoulder joint is called the
glenohumeral joint
The acromioclavicular joint is
posterior or behind the clavicle joints
arm rotation outward is called
lateral rotation
arm rotation inward is called
medial rotation
link the vertebral column or rib cage (axial skeleton) to the scapula, clavicle or humerus (appendicular skeleton).
Thoraco-appendicular muscles
Thoracoappendicular muscle include
1)Subclavius
2) Pectoralis Minor
3) Pectoralis Major
Adducts and medially rotates the humerus.
Pectoralis Minor: Inferior rotation of the scapular glenoid.
Subclavius: Depresses the lateral end of the clavicle.
Serratus Anterior: Protracts (Abducts) the scapula and superiorly rotates the glenoid of the scapula to enable full abduction of arm.
(When the scapula is fixed, the serratus anterior muscle
link the scapula to the humerus. These include the deltoid, the teres major muscles and the 4 rotator cuff muscles.
Scapulo-humeral muscles
Note that several major Arm muscles are technically “scapulohumeral” muscles. However, for the most part, these act on the elbow joint and are discussed with the arm rather than the shoulder (e.g. biceps and triceps).
Pectoralis Major Muscle:
Pectoralis Major Muscle:
Origins: clavicular head, sternocostal head, abdominal head
Nerve: lateral & medial pectoral nerves. Main Function: ADDucts and medially rotates the humerus.
Pectoralis Minor Muscle:
Pectoralis Minor Muscle:
Origin: upper margins of ribs 3-5
Insertion: coracoid process of scapula
Nerve: medial pectoral nerve
Main function: downward (inferior) rotation of the scapula
Origin: lateral clavicle, spine of scapula, acromion
Insertion: deltoid tuberosity of humerus
Nerve: axillary
Function: aBducts arm, also flexes and extends arm
Deltoid
Origin: inferior angle of scapula
Insertion: medial bicipital (intertubercular) groove of humerus
Nerve: lower subscapular
Function: aDDucts and medially rotates arm
TERES MAJOR
Origin: supraspinous fossa of scapula
Insertion: superior part of greater tubercle of humerus
Nerve: suprascapular
Function: assists deltoid in aBducting arm
SUPRASPINATUS
Origin: infraspinous fossa of scapula
Insertion: medial facet of greater tubercle of humerus
Nerve: suprascapular
Function: laterally rotates humerus
Infraspinatus
Origin: posterolateral border of scapula
Insertion: lower part of greater tubercle
Nerve: axillary
Function: aDDucts and laterally rotates humerus
Teres Minor
What tendon is the most commonly torn of the rotator cuff muscle. what nerve is affected
supraspinatus
suprascapular nerve
Origin: subscapular fossa
Insertion: lesser tubercle of humerus; capsule of shoulder joint
Nerve: upper and lower
subscapular
Function: medially rotates humerus
Subscapularisg
There are 2 muscle compartments in the arm
Anterior- All anterior compartment muscles are innervated by the musculocutaneous nerve
Posterior- All posterior compartment muscles are innervated by the radial nerve
Radius is located
This is the shorter bone located on the lateral or **thumb side. hThe head of the radius and the radial tuberosity are proximal; the styloid process is distal.
