Shoulder girdle and shoulder joint Flashcards
Which structures articulate in order to form the shoulder joint?
Head of the humerus and glenoid fossa
What is each articular surface covered by?
Hyaline cartilage
Articular disc that lies in the glenoid cavity and is usually deep
Glenoid labrum
Why do we need the glenoid labrum to be deep ?
To stabilize the joint
What does the fibrous membrane form when it thickens?
ligaments
What does the fibrous membrane form when it thickens?
ligaments
What does the fibrous membrane attach to?
Margin of the glenoid cavity
Where is the coraco humeral ligament located
Superiorly, between coracoid process and humerus (Coracohumeral ligament)
Where are transverse humeral ligaments located?
Between greater and lesser tubercles of the humerus
- Transverse humeral ligament
Where is the Coraco acromial ligament located?
Between coracoid process and acromion process
- Coraco-acromial ligament
Bursae
Synovial membrane protrudes through to form bursae.
Why does it protrude?
- To reduce friction between tendons and other structures
What is the most consistent bursa?
the subtendinous bursa
Where is the subtendinous bursa found?
- Between subscapularis muscle and fibrous membrane
Where is the subacromianal bursa found?
Between acromion and supraspinatus muscle
- Between deltoid and supraspinatus muscles
Where deos the trapezius muscle originate?
Superior nuchal line
External occipital protuberance
Nuchal ligament
Spinous process of C7 to T 12
Where deos the trapezius muscle insert
Upper fibres on lateral 1/3 of the clavicle
- Middle fibres on acromion and scapula spine
- Lower fibres on tubercle of scapula spine
What makes up the shoulder girdle?
Shoulder girdle formed by scapula and clavicle
Girdle is the link between the thorax and upper limb.
What action does the trapezius play a role in?
- Scapula elevation, scapula rotation during abduction (Upper)
- Scapula retraction (Middle fibres)
- Scapula depression (Lower fibres)
what are the nerves that run through the trapezius muscle.
- Accessory nerve (CN XI)
Where does the levator scapulae muscle originate?
- Transverse processes of C1-C4
Where deos the levator scapulae muscle insert?
- Superior border of the scapula
What action deos the levator scapula muscle perform
- Shoulder elevation
- Assists in lateral rotation of the scapula
What are the nerves that run through the levator scapulae muscle?
Dorsal scapular nerve (C5)
- Anterior rami of C3-C5 spinal nerves
Where deos the Rhomboid minor muscle lie?
Lies deep to trapezius
Where deos the Rhomboid minor muscle originate?
Lower end of nuchal ligament
- Spinous process of C7 – T1
Where deos the Rhomboid minor muscle insert?
- Medial border of the scapula
- Until root of the spine of the scapula
What action deos the rhomboid minor and major perform
- Holds scapula against the thoracic wall
- Retracts the scapula
- Assists in elevation of the scapula
What nerves run through the rhomboid minor and major muscle
Dorsal scapular nerve (C4 - C5)
What deos the serratus anteriour muscle originate?
Finger-like processes from ribs 1 – 8 laterally
Where deos the serratus anterior muscle insert?
Costal surface of the medial border of the scapula
What actions deos serratus anterior perform?
Holds scapula against the thoracic wall
- Protraction and rotation (in abduction) of the scapula
What are the nerves that run through the serratus anterior muscle
Long thoracic nerve (C5 - C7)
Where does the subclavius muscle originate?
- First rib and its costal cartilage
Where does the subclavius muscle insert?
Inferior surface of the middle 1/3 of the clavicle
What are it’s actions( subclavius muscle)
Anchors and depresses the clavicle
What are some of the nerves that run through the subclavius?
Nerve to subclavius (C5 – C6)
Where deos the Pectoralis major muscle lie?
Lies deep to the breast
- Separated from it via the deep fascia
Where does the pectoralis major muscle originate?
Anterior border of the medial half of the clavicle
- Anterior surface of the sternum and ribs 1-7 costal cartilage
- Aponeurosis of the External oblique muscle
Where does the pectoralis major muscle insert?
Lateral lip of intertubercular sulcus of the humerus
What actions does the pectoralis major muscle perform?
Adduction
- Medial rotation
- Clavicular fibres flex at the shoulder joint
What are the nerves that run through it? (pec major?)
- Medial and lateral pectoral nerves
Where deos the pectoralis minor muscle originate?
Anterior surfaces and superior border of ribs 3 to 5
Where deos the pectoralis minor muscle insert
Medial border of the coracoid process of the scapula
What actions deos the pectoralis minor muscle perform?
Protracts and depresses shoulder
What nerves run through the pectoralis minor muscle perform?
Innervation by the Medial pectoral nerve
Where does the latissimus dorsi muscle?
- Spinous processes of T7 to L5
- Posterior surface of the sacrum
- Posterior part of iliac crest
- Rib 9 - 12
Where does the latissimus dorsi muscle insert?
- Floor of the intertubercular sulcus
What actions deos the latissimus dorsi muscle perform?
- Extension
- Medial rotation
- Adduction
What actions deos the latissimus dorsi muscle perform?
- Extension
- Medial rotation
- Adduction
What nerves run through the latissimus dorsi muscle?
Thoracodorsal nerve (C6 – C8
