Anatomy of shoulder region Flashcards
What is meant by the shoulder girdle?
a set of bones found in the appendicular skeleton connecting the arm on either side
What forms the pectoral girdle?
The clavicle & Scapula
What is the skeleton of the pectoral region?
1) Sternum
- Manubrium
- Body
- Xiphoid process
2) Clavicle
3) Ribs (first rib joint is a fibrous cartilage rest are synovial)
4) Scapula
5) Humerus
Where is the sternoclavicular joint?
Between the sternum and the clavicle
Where is the sternal angle (AKA angle of Luis)?
it is between the body and the manubrium of the sternum, It is the point where the second rib is attached
Where can we find the jugular notch (AKA suprasternal notch)?
It is the V dent above the manubrium
What is the costochondrial junction?
The junction between each rib and the cartilage that attaches it to the sternum
What is the last rib that is attached to the sternum?
7 (8-10 are attached to 7), while 11 and 12 are not attached
Describe the clavicle
- Connects the arm to the body
- The only long bone that lies horizontally in the body
- It is the first bone to ossify in the body (5th week of fetal life)
- Convex from the anterior towards 2/3 to the medial side
- Concave from the posterior
What is the anatomy of the clavicle?
1) 2 Ends (Acromial/lateral/flat end “articulates with the scapula”& sternal/medial/rounded end “articulates with the sternum”)
2) 2 surfaces (smooth superior, rough inferior it has the conoid tubercle (opposite to the acromial extremity) and the costal tuberosity (close to the sternal extremity) which acts as an attachment site for the scapula via the coracoclavicular ligament)
3) 2 borders
What is the role of the clavicle?
It carries the upper arm away from the axial skeleton, thus if there is a fracture the upper arm will fall
Describe the clavicle in more detail
1) 1/3 of the lateral end is concave, and the other 2/3 of the medial end is concave
2) In the inferior surface clavicle we have the costal tuberosity (attachment for the scapula), conoid tubercle (attachment for the scapula), and the trapezoid line (connected to the coracoid process of the scapula)
3) Subclavis groove, connected to the muscle subclavius
What is the cervico-axillary canal
- Forms the apex of the axilla
- It is the passageway which extends between the neck and upper limb where the main vessels passes to and from the upper limb
What are the boundaries of the cervico-axillary canal?
1) Posteriorly: The upper border of the scapula
2) Anteriorly: The clavicle
3) Medially: Outer border of the 1st rib
What are the important structures that go into the canal?
1) Subclavical artery
2) Subclavical vein
3) Nerves (brachial plexus)
-any fracture in the bone surrounding the canal will be dangerous because it contains arteries veins and nerves
Describe the scapula
It is a flat triangular structure that lies posterolateral to the thoracic cage
What are the features of the scapula?
1) 2 surfaces:
- Anterior/coastal “as it is related to the ribs”
- Posterior
2) 3 Angles:
- Superior angle
- Inferior angle
- Glenoid fossa laterally
3) 3 borders:
- Lateral border
- Medial Boarder
- Superior border
4) 4 fossae:
- 3 muscular fossae
subscapular (attached to the subscapularis in the anterior surface), supraspinous fossa (attached to the supraspinatus muscle in the posterior surface above the spine), and infraspinous fossa (attached to the infraspinatus muscle) - 1 Articular fossa (glenoid fossa, attaches to the humerus which forms the glenohumeral joint “shoulder joint”)
5) 2 processes:
- Acromion
- Coracoid
What is the meaning of a fossa?
rounded oval smooth depression
What is the difference between muscular and articular fossa?
The muscular is attached to muscle and the articular is attached to bones.
Which ligament joins the acromion to the coracoid process?
Coracoacromial ligament
The coracoacromial ligament joins two processes
It joins the acromion to the coracoid process
What joins the clavicle to the coracoid process?
The coracoclavicular ligament