Pectoral girdle Flashcards
What are the 4 parts of the arm? What are the divisions?
Parts:
- Shoulder
- Arm
- Forearm
- Hand
Divisions:
- Axilla
- Cubital fossa
- Carpal tunnel
What is the pectoral girdle composed of posteriorly and anteriorly?
Posterior- Scapulae and clavicales (incomplete)
Anteriorly- Clavicle to sternum- (completed)
Elevate and depress your shoulder. Protract and retract your shoulder
Elevate- up
Depress- down
Protract- foward
Retract- backwards
What does the clavicle attach to? Name the associacted joints
- Attches to sternum- sternoclavicular joint
- Attches to acromion of scapula- Acromioclavicular joint
Main function of the clavicel?
Keep arm away from thorax
Look at this image of a fractured clavicle and explain the presenation
The action of the sternocleidomastoid muscle is pulling the medial fragment (clavicle) superiorly (forwards)
Look at this X ray of a fractured clavicle, explain what the image is showing
The weight of the arm is dragging the lateral fragment downwards (inferiorly)
What is in danger when the clavicle is fractured? AKA what does the clavicale protect?
The brachial plexus
Major underlying vesseles (axillary artery and vein)
Apex of the lung
What is the scapula? Which ribs does it lie over?
Triangula flat bone
Lies over the 2nd and 7th ribs
Is there a joint between the scapula and the thorax? If so, name it
physiological scapulothoracic joint
Which mucles attache to he clavicle?
shoulder/ pectoral girdle mucles
What is the spine of the scapula? What does it seperate?
Ridge on the posterior side
Seperates the supraspinous fossa from the infraspinous fossa
What is the acromion?
Lateral end of the spine of the scpula- the point of the shoulder
What is the largest bone in the upper limb?
Humerous
What does the humerous articulate with? Name the joint
Articulates with the scapula at the glenohumeral joint
Articultes with the radius and ulna at the elbow joint
Describe the sternoclavicual jont
Lies between the clavicle and manubrium of the sternum
Only articulation between the upper limb and the axial skeleton
Where is the first costal cartilage loctated?
Sternoclavicular joint
What do these images depict?
Dislocation of the sternoclavicular joint
Describe the acromioclvicular joint
Connects the acromion and clavicle
2-3cm away from point of shoulder
No msucles across the AC joint
Mucles which move the scapula move the AC joint
How does the Acromioclavicular joint move?
It has no msucles attcahed onto it
Mucles which move the scapula move the AC joint
Describe the physiological scapulathoracic joint in terms of shoulder Abduction
Used for ABduction
head of humerous uses 90 degrees
Scapula needs to rotate to allow the remainder
–Uses serratus anterior (inferior) and trapezius (descending)
•For every 15o of shoulder abduction
–Glenohumeral joint gives 10o
–Scapulothoracic joint gives 5o
•So 180o of shoulder abduction
–120o occurs at glenohumeral joint
–60o occurs at scapulothoracic joint
Explain the main features of the glenohumeral joint (label a picture of the joint and its ligaments)
Articulation between the head of the humerous and the genoid cavity
Shallow glenoid cavity deepned by glenoid labrum
The joint capsule is loose and baggy because head of the humerous is larger than the cavity
There are very little muscles to keep the joint in place
Movments of the glenohumeral joint
–flexion-extension,
–abduction-adduction,
–medial and lateral rotation,
–circumduction (combination of all movements).
Which mucsles are responsible for elavation of the scapular?
–Trapezius descending part
