Appendicular Skeleton: The Upper Appendage Flashcards
The Appendicular Skeleton
Made of mobile appendage with a similar pattern of bones between upper and lower limbs
Upper Limbs
Phalanges, metacarpals, carpals, radius, ulna, humerus
Pectoral Girdle
Scapula and Clavicle
Clavicle
Little bone that is composed of the saddle joint (sternoclavicular joint) and the acromioclavicular joint
Sternoclavicular joint
Clavicle forms saddle joint with the sternum (facial skeleton and upper limb)
- Cannot rotate
Acromioclavicular Joint
The acromial end of the clavicle joins with the acromion of the joint
- Fixed joint with no significant motion
Scapula
Flat, triangular and glides over the posterior surface of the thorax
Coracoid Process
Attachment for the biceps of the brachii and other muscles of the shoulder
Acromion
Joins the scapula to the clavicle at the immobile acromioclavicular joint
- close to the skin and palpable
Spine of the Scapula
Follows the acromion medially and forms a ridge that separates the posterior surface into supraspinous fossa and infraspinous fossa
* 3 fossa house the rotator cuff muscles
Subscapular Fossa
The entire concave anterior surface that faces the ribs
Glenoid Cavity
Forms part of the shoulder joint where the head of the humerus articulates with the scapula
Contractions of Scapula
- Protraction: Scapula slides laterally and somewhat anteriorly (reaching for something out of reach)
- Retraction: pull scapulae towards the back center and scapula moves medially
- Elevation: shrugging your shoulders and scapula moves superiorly
- Depression: inferior movement of scapula
Humerus
THe only bone within the brachium (upper arm)
Head of the Humerus
Near 2 tubercles
Lateral Greater Tubercle and Medial Lesser Tubercle
The 2 tubercles near the head of the humerus
Intertubercular grouove
Lies between the greater and lesser tubercles
- An attachment site for some muscles that move the humerus
Anatomical Neck
At the epiphyseal plate that separates the head of the humerus from its diaphysis
Surgical Neck
More commonly fractures than the anatomical neck and it is narrower
Glenohumeral Joint
- Ball and socket joint = a wide range of motion
- Shoulder
- B/w glenoid fossa of the scapula and the head of the humerus
Movements of the Humerus
- Internal Rotation: of the glenohumeral joint (shoulder) rotates humerus inwardly
- External Rotation: of shoulder joint rotates humerus outwardly
- Extension: of shoulder moves humerus posteriorly
- Flexion: of shoulder moves humerus anteriorly
- Adduction: of shoulder moves humerus towards body
- Abduction: of shoulder moves humerus away from body
Distal Humerus
Humerus has 2 condyles (prominent articular surfaces)
Trochlea
Spool-shaped condyles and articulates with the ulna
- Condyle at distal humerus
Capitulum
Somewhat spherical and articulates with the radius
- Condyle at distal humerus
Olecranon fossa
On the posterior surface that allows for full extension of the elbow (humeroulnar joint)
Epicondyles
Prominent ridges outside of the condyles
Medial Epicondyle
Attachment for most of the anterior forearm muscles
Lateral Epicondyle
Attachment for most of the posterior forearm muscles
Radius and Ulna
2 bones of the forearm
- Radius: laterally on thumb side
- Ulna: medially on pinky side
Interosseous Membrane
Along the shaft of both the radius and ulna
- Ligamentous connection that holds the bones together
Styloid Process
Distally, where radius and ulna bone terminates
Elbow Joint
3 bones and 3 joints
Humeroulnar Joint
- Flexion (bends elbow) and extension (straightens elbow)
- hinge joint
- ulna rips humerus trochlea like a wrench
Coronoid Process and Olecranon process
2 sides of the wrench of the ulna that grips grips trochlea
Olecranon Process
Attachment site for the powerful extensors of the elbow
Humeroradial Joint
Radius articulates with the capitulum in what looks like a ball and socket joint, but the range of motion of this joint is LIMITED
-Only flexion, extension, and rotation are possible
Head of the Radius
External rotation of the head of the radius against the capitulum produces supination (external rotation of radius = anterior facing palm)
- Protonation: moves palm to face posteriorly
(Proximal Radioulnar Joint)
Proximal Radioulnar Joint
Limited motion
- Radial head fits into a crescent-shaped depression in the ulna (Radial Notch)
- Articulation = pivot joint (permits supination and protonation)
Wrist and Hand
8 carpal bones = wrist
Radiocarpal Joint
Primary joint of the wrist (condyloid joint b/w radius and ulana and proximal row of carpals)
- Flexion, extension, adduction, abduction
Joints between Carpals
Plane joints (joints slide past each other)
Metacarpals
5 metacarpals support the pal of the hand that articulate with the distal row of 4 carpals and the 5 proximal phalanges of the digits
Metacarpophalangeal joints
B/w metacarpal bones and proximal phalanges (condyloid joints: flexion, extension, abduction, adduction)
Proximal Interphalangeal Joints
B/w proximal and intermediate phalanx of the digit (hinge joint: flexion, extension)
Distal Interphalangeal Joints
B/w intermediate/distal phalanges (flex and extend)
Digits II-V
3 phalanges each: proximal, intermediate, distal phalanges
Digit I
Pollex (lacks intermediate phalanx)
Metacarpal Bones I-V
Make up the palm of the hand and articulate with the 5 proximal phalanges and the distal row of 4 carpals
Distal Row of Carpals
Capitate, Hamate, Trapezium, Trapezoid
Proximal Row of Carpals
Scaphoid, lunate, triquetrum, pisiform
