2 - Shoulder and Arm Flashcards
What are the two main processes coming off the scapula?
Coracoid process
Acromion process
How can you differentiate between the 2 ends of the clavicle?
sternal end = round
acromial end = flattened
How can you differentiate between the anterior and posterior surface of the clavicle?
anterior = smooth posterior = roughened
Why is the sternoclavicular joint described as being the pivot point of the limb?
joint between the trunk and the clavicle - the ONLY bony attachment between the upper limb and the trunk:
- shoulder joint (gleno-humeral) is between the humerus and the scapula
- the scapula does not have a bony joint with the trunk (it is a virtual joint)
Name the muscles of the scapula
deltoid
trapezius
subclavius
What are the differences between the anatomical and surgical necks of the humerus?
Anatomical – between the head of the humerus and everything else
Surgical – the main narrowing of the distal humerus – it is the most common site for fractures of the humerus
Which part of the scapula articulates with the humerus?
Glenoid cavity
What are the three fossae of the scapula?
Supraspinous
Infraspinous
Subscapular
On which bones are deltoid tubercles found?
Spine of the scapula
Humerus
What is the name given to the distinctive notch on the scapula?
Suprascapular notch
What is the name given to the groove between the greater and lesser tubercles of the humerus?
Intertubercular (bicipital) groove
What are the two distinctive protrusions on the lateral third of the clavicle and what are their roles?
Conoid tubercle
Trapezoid line
They are the point of attachment of the conoid ligament and trapezoid ligament (both part of the coracoclavicular ligament)
What are the names of the three fossae at the distal end of the humerus?
Anterior – coronoid and radial fossae
Posterior – olecranon fossa
Name the condyles, describe their shape and name the bone that they attach
NOTE: these are important for articulation at the elbow joint
capitulum - round - radius attaches
trochlea - cylindrical - ulner attaches
What are the five muscle compartments of the region?
Anterior pectoral Posterior pectoral Intrinsic shoulder Anterior compartment of arm Posterior compartment of arm
Which muscles make up the anterior pectoral compartment?
Pectoralis major
Pectoralis minor
Serratus anterior
Subclavius
What are the attachments of pectoralis major?
Medial 1/3 of the clavicle + sternum + costal cartilages
Lateral lip of intertubercular sulcus
What are the actions of pectoralis major?
Adducts and medially rotates the shoulder
What are the attachments of pectoralis minor?
Ribs 2-5
Coracoid process of scapula
What is the function of the pectoralis minor?
pulls the scapula forward to the back of the thoracic wall
What are the attachments of subclavius?
1st costochondral joint
Clavicle
What function does the subclavius perform?
anchors the clavicle
What are the attachments of serratus anterior?
Medial border of the costal surface of the scapula
Anteriorly attaches to the ribs (1-9)
Which nerve innervates serratus anterior?
Long-thoracic nerve
Which muscles make up the posterior pectoral compartment?
Trapezius
Latissimus dorsi
Levator scapulae
Rhomboids (minor and major)
What is the motor supply to trapezius?
Accessory nerve (CN XI)
Other than the trapezius, what else does the accessory nerve innervate?
the sternocleidomastoid
Describe the attachments of latissimus dorsi.
Thoracolumbar fascia and posterior 1/3 of the iliac crest
Floor of the intertubercular sulcus
What movement is latissimus dorsi responsible for?
Extends, adducts and rotates the humerus
pulls the body up during climbing
Describe the attachments of the rhomboids.
Both attach distally to the medial border of the scapula
Rhomboid minor attaches proximally to the spinous processes of C7 and T1
Rhomboid major attaches proximally to the spinous processes of T2-T5
Which nerve supplies the rhomboids?
Dorsal scapular nerve
What movement are the rhomboids responsible for?
Retracts, rotates and fixes the scapula