shoulder girdle and shoulder joint Flashcards
the shoulder (glenohumeral) joint is formed by articulation of
the head of the humerus and glenoid fossa of scapula
what is each articular surface covered by
hyaline cartilage
fibrous membrane of joint capsule attaches to what
the margin of the glenoid cavity
anatomical neck of the humerus
fibrous membrane thickens to form what
ligaments
what ligaments are found anteriorsuperiorly
Superior, middle and inferior glenohumeral ligaments
what lies superiorly between coracoid process and the humerus
coracohumeral ligament
what is between the greater and lesser tubercles of the humerus
the transverse humeral ligament
what is between the ciracoid process and acromion process
coraco-acromial ligament
what is the function of bursae
to reduce friction between tendons and other structures
where is the subtendinous bursa found
Between subscapularis muscle and fibrous membrane
where is the subacromial(subdeltoid) bursa found
Between acromion and supraspinatus muscle
- Between deltoid and supraspinatus muscles
the shoulder girdle is formed by
the scapula and clavicle
the girdle is the link between
the thorax and upper limb
origin of the trapezius muscle
Superior nuchal line
- External occipital protuberance
- Nuchal ligament
- Spinous processes of C7 to T12
insertion of the trapezius muscle
Upper fibres on lateral 1
3 of the clavicle
- Middle fibres on acromion and scapula spine
- Lower fibres on tubercle of scapula spine
innervation of the trapezius muscle
Accessory nerve (CN XI)
actions of the trapezius muscle
Scapula elevation, scapula rotation during abduction (Upper)
- Scapula retraction (Middle fibres)
- Scapula depression (Lower fibres)
facts about the lecators scapulae muscle
Origin
- Transverse processes of C1-C4
* Insertion
- Superior border of the scapula
* Action
- Shoulder elevation
- Assists in lateral rotation of the scapula *Innervation
- Dorsal scapular nerve (C5)
- Anterior rami of C3-C5 spinal nerves
facts about the rhomboid minor muscle
Lies deep to trapezius
* Origin
- Lower end of nuchal ligament
- Spinous process of C7 – T1
* Insertion
- Medial border of the scapula
- Until root of the spine of the scapula
facts about the rhomboid major muscle
Lies deep to trapezius, inferior to the rhomboid minor
* Origin
- Spinous process of T1 – T4
* Insertion
- Medial border of the scapula
- Until the inferior angle of the scapula
facts about the rhomboid minor and major
Action
- Holds scapula against the thoracic wall
- Retracts the scapula
- Assists in elevation of the scapula
* Innervation
- Dorsal scapular nerve (C4 - C5)
facts about the serratus anterior muscle
Origins
- Finger-like processes from ribs 1 – 8 laterally
* Insertion
- Costal surface of the medial border of the scapula
* Actions
- Holds scapula against the thoracic wall
- Protraction and rotation (in abduction) of the scapula
* Innervation
- Long thoracic nerve (C5 - C7)
facts about the subclavios muscle
Origin
- First rib and its costal cartilage
* Insertion
- Inferior surface of the middle 1
3 of the clavicle
* Action
- Anchors and depresses the clavicle
* Innervation
- Nerve to subclavius (C5 – C6)
facts about the pectoralis major muscle
- Lies deep to the breast
- Separated from it via the deep fascia
- It has 3 origins
- 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
- Insertion
- Lateral lip of intertubercular sulcus of the humerus
*Action - Adduction
- Medial rotation
- Clavicular fibres flex at the shoulder joint
- Innervation
- Medial and lateral pectoral nerve
pectoralis minor muscle
Origin
- Anterior surfaces and superior border of ribs 3 to 5
* Insertion
- Medial border of the coracoid process of the scapula
* Action
- Protracts and depresses shoulder
* Innervation by the Medial pectoral nerve
facts about the latissimus dorsi muscle
Origin
- Spinous processes of T7 to L5
- Posterior surface of the sacrum
- Posterior part of iliac crest
- Rib 9 - 12
* Insertion
- Floor of the intertubercular sulcus
* Action
- Extension
- Medial rotation
- Adduction
* Innervation
- Thoracodorsal nerve (C6 – C8)
facts about the deltoid muscle
Origin
- Anterior border of the lateral 1
3 of the clavicle
- Inferior lip/edge of the spine of the scapula
- Lateral border of acromion
* Insertion
- Deltoid tuberosity of the humerus Action
- Major abductor at the shoulder joint beyond 15°
- Anterior fibres flex and medially rotate
- Posterior fibres extend and laterally rotate
* Innervation
- Axillary nerve (C5 – C6)
facts about the teres major muscle
Origin
- Posterior surface of the inferior angle of the scapula
- On the lateral border
* Insertion
- Medial lip of the intertubercular groove
* Action
- Medial rotation and extension
* Innervation
- Lower subscapular nerve (C5 - C7)
facts about the supraspinatus muscle (Rotator cuff)
Origin
- Supraspinous fossa
* Insertion
- Superior facet of the greater tubercle of the humerus
* Action
- Initiation of abduction
* Innervation
- Suprascapular nerve (C5 – C6)
facts about the infraspinatus muscle(Rotator cuff)
Origin
- Infraspinous fossa
* Insertion
- Middle facet of the greater tubercle of the humerus
* Action
- Lateral rotation
* Innervation
- Suprascapular nerve (C5 – C6)
facts about the teres minor muscle(Rotator cuff)
Origin
- Upper 2
3 of the posterior surface of the lateral border of the scapula
* Insertion
- Inferior facet of the greater tubercle of the humerus
* Action
- Lateral rotation
* Innervation
- Axillary nerve (C5-C6)
facts about the subcapularis muscle(Rotator cuff)
Origin
- Upper 2
3 of the posterior surface of the lateral border of the scapula
* Insertion
- Inferior facet of the greater tubercle of the humerus
* Action
- Lateral rotation
* Innervation
- Axillary nerve (C5-C6)
SHOULDER GIRDLE
