Joints of the Upper Limb (Shoulder) Flashcards
The pectoral girdle is formed by the ___ and ___
clavicle and scapula
The pectoral girdle can be considered a “strut” system. Define “strut”
A strut, as part of a framework, is a rod or bar designed to resist compression (ex: the clavicle resists the inward pull of the chest/back musculature)
In the pectoral girdle, the clavicular strut also protects and partially defines, a major neuromuscular conduit termed the ______ canal
cervicoaxillary
The clavicle forms the bony connection between the upper limbs an the axial skeleton. It articulates with the ___ laterally, and the ____ medially
acromion; manubrium
What is the function of the clavicle?
acts as a strut to maintain the upper limb separation from the thorax so the arm has increased range of motion
The sternoclavicular joint is a ____ joint, with an internal cartilaginous disc, between the ___ ____ of the manubrium and the sternal facet of the proximal clavicle
synovial; clavicular notch
In regards to the sternoclavicular joint, these ligaments cover either side of the joint and spread onto the respective surfaces of the manubrium
anterior and posterior sternoclavicular ligaments
In regards to the sternoclavicular joint, this ligament connects the superior surfaces of the contralateral clavicles. This ligament follows the contours of the superior surface of the manubrium, including the large median depression, the jugular notch
interclavicular ligament
In regards to the sternoclavicular joint, this ligament connects the inferior surface of the proximal clavicle to the superior surface of the costal cartilage and distal tip of the 1st rib
costoclavicular joint
At full elevation of the limb, the clavicle inclines ____ degrees from transverse, and can depress to ___ degrees
40; 10
At full elevation via flexion, the clavicle rotates on its ___ axis
longitudinal
From anatomical position, the clavicle can protract ___ degrees and retract ___ degrees
30; 25
In regards to the scapula, the coracoid process is inferior, medial, and ventral to the larger ____
acromion
Name and describe the 3 fossa found on the scapula
supraspinous fossa: superior to spine of scapula
infraspinous fossa: inferior to spine of scapula
subscapular fossa: ventral surface of scapula
The acromioclavicular joint has an internal cartilaginous disc between what two structures of the acromion and clavicle?
the acromial facet of the distal clavicle and the anterior end of the acromial process
This ligament attaches the medial base of the coracoid process to the conoid tubercle on the inferior surface of the clavicle
conoid ligament
This ligament attaches the lateral base of the coracoid process to the trapezoid line on the inferior surface of the clavicle
trapezoid ligament
This ligament does not contact the clavicle, rather it spans from the acromion process to the coracoid process, forming a reinforcing arch over the superior surface of the glenohumeral joint
coracoacromial ligament
This muscle is a thick, triangular muscle on the anterior surface of the scapula
subscapularis
What are the attachments of subscapularis?
originates from the sub scapular fossa of the scapula; inserts onto the lesser tubercle of the humerus
What innervates subscapularis?
upper and lower subscapular nerves
What is the action of subscapularis?
medially rotates arm and helps stabilize shoulder joint, as a rotator cuff
This muscle is an extensive sheet of muscle characterized by its focal attachments on successive ribs giving it a jagged or serrated appearance
serratus anterior
What are the attachments of serratus anterior?
originates from the lateral surface of ribs 1-8; inserts onto the medial border of the scapula
What innervates serratus anterior?
Long Thoracic nerve
What is the action of serratus anterior?
primary protractor of the scapula
The scapulothoracic joint is a muscular joint formed between three planes of muscle. What are they?
Superficial: subscapularis
middle: serratus anterior
deep: external intercostals and ribs
Movement occurs between each plane of the scapulothoracic joint. To smooth these movements. There are two bursa. Name and describe location of these two bursa.
Subscapular bursa: between subscapularis and serratus anterior
Scapulothoracic bursa: between serratus anterior and the external intercostals
This is a small cord of muscle located inferior to the proximal end of the clavicle
subclavius