Appendicular Skeleton- Upper Extremities Flashcards
What is the pectoral girdle?
- Articulates with the trunk and supports the upper limbs
- Consists of the right and left clavicles and the right and left scapulae
- Attachment site for many muscles that move the upper limbs
How does the pectoral girdle promote upper limb mobility?
- Because the scapula isn’t directly attached to the axial skeleton, it moves freely across the posterior surface of the thorax, permitting the arm to move with it
- The shallow cavity of the shoulder joint permits a wide range of movement of the upper limb
What are the clavicles?
- Commonly known as collarbones
- S-shaped bones that extend between the manubrium of the sternum and the acromion of the scapula
- The only direct connection between the pectoral girdle and the axial skeleton
What is the sternal end of the clavicle?
- The medial end which is roughly pyramidal in shape
- Articulates with the manubrium of the sternum
- Forms the sternoclavicular joint
What is the acromial end of the clavicle?
- The lateral end which is broad and flattened
- Articulates with the acromion of the scapula
- Forms the acromioclavicular joint
What is the conoid tubercle of the clavicle?
- A rough tuberosity on the inferior surface of the clavicle
- The attachment site for the coracoclavicular ligament
What is the costal tuberosity of the clavicle?
- A rough tuberosity on the inferior surface of the clavicle
- More inferior than the conoid tubercle and located on the sternal end of the clavicle
- Attachment of the shoulders costoclavicular ligament
What are the scapulae?
- Broad, flat, triangular bones that you can palpate by moving your shoulders
- Several large projections extend from the scapula and provide surface area for muscle and ligament attachments
What is the spine of the scapula?
- A ridge of bone on the posterior aspect
What is the acromion of the scapula?
- Continuous projection from the spine
- A larger, flattened, posterior process that forms the bony tip of the shoulder
- Articulates with the acromial end of the clavicle
What is the coracoid process of the scapula?
- Is a smaller more anterior projection of the shoulder
What is the superior border of the scapula?
- The horizontal edge of the scapula
- Superior to the spine of the scapula
What is the medial border of the scapula?
- The edge of the scapula that is closest to the vertebrae
What is the lateral border of the scapula?
- The edge of the scapula that is closest to the axilla (armpit)
What is the suprascapular notch?
- In some people, this is the suprascapular foramen
- In the superior border
- Provides a passage for the suprascapular nerve
What is the superior/inferior/lateral angles of the scapula?
- The pointed part of the scapula between the superior and medial borders (superior angle)
- The pointed part between the superior and lateral borders (inferior angle)
- Composed primarily of the cup-shaped, shallow glenoid cavity which articulates with the humerus bone of the arm (lateral angle)
What are the supraglenoid and infraglenoid tubercles of the scapula?
- Near the superior edge of the glenoid cavity (supra)
- Near the inferior edge of the glenoid cavity (infra)
What are the subscapular fossa? (scapula)
- The broad, relatively smooth, anterior surface of the scapula
- Slightly concave and relatively featureless
- Large muscle called the subscapularis overlies this fossa
What are the supraspinous/infraspinous fossa? (scapula)
- The spine divides the posterior surface of the scapula into 2 shallow depressions
- Depression superior to the spine (supra)
- Depression inferior to the spine (infra)
- The supraspinatus and infraspinatus muscles respectively attach to these fossae
What bones make up the upper limbs?
- Each upper limb contains 30 bones
- Brachium (arm), antebrachium (forearm), and the hand make up the upper limb
What is the humerus?
- The longest and largest upper limb bone
- Proximal end has a hemispherical head that articulates with the glenoid cavity of the scapula
- Adjacent to the head are 2 tubercles
What is the greater tubercle of the humerus?
- Adjacent to the head of the humerus
- Positioned more laterally
- Helps form the rounded contour of the shoulder
What is the lesser tubercle of the humerus?
- Adjacent to the head of the humerus
- Smaller and located more anteromedially