Pectoral Girdle and Shoulder SDL Flashcards
(110 cards)
Describe the lateral 1/3 of the clavicle
Concave
Describe the medial 2/3 of the clavicle
Convex
What does the lateral end of the clavicle articulate with?
Acromion –> AC join

What does the medial end of the clavicle articulate with?
Manubrium of sternum and first costal cartilage –> sternoclavicular joint
How do clavicular fractures usually occur?
Usually occur by a direct blow to the shoulder e.g. during a fall or a car collision
Which part of the clavicle usually fractures?
The middle portion (shaft) of the bone
Where does the scapula lie?
Lies on the back of the rib cage between the second and seventh ribs
Where does the scapula articulate with the humerus?
At the glenoid fossa to form the shoulder (glenohumeral) joint
What is the dorsal surface of the scapula divided into?
Supraspinous and infraspinous by the spine of the scapula
What holds the scapula and clavicle together?
Extremely strong ligaments
What are the movements of the scapula?
• up and down (elevation and depression) • forwards (protraction = reaching the arm out in front, as if to push open a door, or throw a punch) • backwards (retraction = ‘squaring’ the shoulders) over the chest wall.
How does the scapula move so the arm can be lifted above the head?
The scapula can move so that the inferior angle can be moved laterally and cranially from the anatomical position. This movement brings the face of the glenoid cavity upwards and allows the arm to be lifted above the head
Where are muscles the move the scapula attached to?
The pectoral girdle, trunk, head and neck
What are the 2 groups of muscles that move the pectoral girdle?
- Dorsal (posterior) group 2. Ventral (anterior) group
What is the dorsal group of muscles comprised of?
2 superficial muscles and 3 deep muscles Superficial: trapezius, lat dorsi Deep: rhomboid major, rhomboid minor, levator scapulae
Diagram of humerus

Palpating scapula on person

Label the muscles

- Trapezius
- Lat dorsi
- Rhom minor
- Rhom major
Origin and insertion of the trapezius?

Origin:
- Superior fibres: superior nuchal line, external occipital protuberence (lower part of skull)
- Middle fibres: nuchal ligament, spinous processes of C1-C6 and C7-T3
- Inferior fibres: spinous processes of T4-T12
Insertion:
- Superior fibres: clavicle
- Middle fibres: acromion and spine of scapula
- Inferior fibres: spine of scapula

What is the trapezius innervated by?
Is the only muscle of the upper limb that does not receive its innervation from the brachial plexus.
Motor: accessory nerve (CN XI)
Sensory: ventral rami C3-C4
Movements on scapula of upper fibres alone of trapezius?
Elevates scapula
Movements alone of middle fibres of trapezius on scapula?
Retracts scapula
Movements alone of inferior fibres of trapezius on scapula?
Depresses scapula
Movement on scapula of all fibres of trapezius working together?
Head and neck extension









































