The Upper Extremity (bones, jnts, ligs) Flashcards
What is the appendicular skeleton?
- Shoulder girdle (pectoral girdle): clavicles & scapulae
- Upper limb
- Pelvic Girdle (innominate bones): illium, ischium, pubis
- Lower limb
What is the axial skeleton?
- Skull, vertebral column, ribs
The shoulder girdle is attached to the axial skeleton at one point only:
Sternoclavicular jnt
Characteristics of the shoulder girdle:
- Weak & unstable
- very mobile
What is scapulothoracic rhythm?
For 170/180 degrees of abduction (2:1 ratio GH to ST):
- glenohumeral (GH) mvmt: 2 degrees
- Scapular (ST) mvmt: 1 degree
- Clavicle mvmt: 30 degrees
What happens when you fracture your clavicle?
Shoulder “drops”
Describe the clavicle b.
- Double curved
- Medial curve: convex anteriorly
- Lateral curve: concave anteriorly
- Articulates with manubrium (top part of sternum)
- Medial (sternal) end: large, round
- Lateral (acromial) end: flat
- One of the most fractured bones
Describe the scapula b.
- Flat, triangular shaped
- Post. thoracic wall (T2-T7 ribs)
- Lat. border thicker (muscle attachments)
- Glenoid fossa (head of humerus)
- Scapular spine: Medial–T3, lateral–acromion process
- Rarely fractured
Which bone of the upper limb is a “sesamoid” bone?
Scapula
What are the 3 major depressions of of the scapula?
- Supraspinous fossa (supraspinatus m.)
- Infraspinous fossa (infraspinatus m.)
- Subscapular fossa (subscapularis m.)
What type of jnt is the sternoclavicular (SC) jnt?
Diarthrosis Synovial “gliding”
Describe the SC jnt.
- Articular disc (fibrocartilage)
- Ant. and Post. SC lig
- Costoclavicular lig (1st rib)
- interclavicular lig (suprasternal notch)
What type of jnt is the Acromioclavicular (AC) jnt?
Diarthrosis synovial “gliding”
Describe the AC jnt.
- Sometimes fibrocartilage Disc (making it more amphiarthrodial jnt)
- common site of injury
- Sup. and inf. AC lig
- Coracoclavicular lig (trapezoid + conoid)
Describe the humerus b.
- Longest b. in upper extremity
- Articulates w/ scapula at GH jnt
- Articulates distally w/ radius + ulna
Where does bicipital tendonitis originate?
Intertubercular (bicipital) groove of humerus b.: long head of biceps brachii m.
Describe the capitulum of the humerus b.
- lateral
- Radial head
Describe the trochlea of the humerus b.
- Medial
- ulnar trochlear notch
What nerve passes thru the medial epicondyle?
Ulnar n.
What type of jnt is the Glenohumeral (GH) jnt?
Diarthrosis synovial “ball-and-socket”
Describe the GH jnt.
- One of 3 shoulder jnts
- Unstable
- frequently dislocated
- mvmt in all directions
- glenoid fossa
- Glenoid labrum (fibrocartilage)
- supraglenoid/infraglenoid tubercles
Describe the shoulder jnt
- Articular capsule
- Anatomical neck of humerus
- GH lig (sup., middle, inf.)
- Coracohumeral lig
- Acromion/coracoid process (coracoacromial lig)
What are 2 common injuries of the shoulder jnt?
- “frozen” shoulder
- Subacromial bursitis
Describe the ulna b.
- Longer than + medial to radius b.
- thick proximal end (olecranon process)
- trochlear notch: hinge of elbow w/ trochlea of humerus b.
- sharp lat. border (interosseous membrane)
- head and styloid process: distal
