Question | Answer |
Upper Limb Major Segments | Shoulder, Arm, Forearm, Hand |
Shoulder | proximal segment, overlaps trunk (thorax & back) & lower lateral neck: Pectoral, Scapular, & Deltoid regions |
Pectoral (shoulder) Girdle | bony ring, incomplete posteriorly, formed by the scapulae and clavicles and completed anteriorly by the manubrium of the sternum |
Arm | L. brachium; centered around Humerus, longest segment of the limb |
Forearm | L. antebrachium; Radius & Ulna, second longest segment of limb |
Hand | L. manus; Carpus, Metacarpus, & Phalanges; distal to the forearm (wrist, palm, dorsum of hand, and digits) |
Clavicle (collar bone) | shaft=double curve/horizontal plane; medial half=convex anteriorly; sternal end=enlarged/triangular where it meets with manubrium of sternum; lateral half=concave; acromial end=flat where it meets with acromion of scapula |
Clavicle (collar bone) Functions | 1. moveable/crane-like strut (rigid support) from which the scapula & free limb are suspended, limb has max ROM
2. bony boundary for cervico-axillary canal (neck/arm) to protect neurovascular supply
3.transmits shock from upper limb>axial skeleton |
Scapula (shoulder blade) | triangular flat bone; posterolateral of thorax, overlying the 2nd-7th ribs; convex posterior surface w/bone ridge=spine-->small supraspinous fossa & large infraspinous fossa; concave coastal surface=supscapular fossa |
Humerus (arm bone) | largest bone in upper limb; articulates w/ scapula @Glenohumeral joint & Radius/Ulna @elbow joint; head, surgical & anatomical necks, greater & lesser tubercles =proximal end; shaft=radial & deltoid; distal end=medial & lateral epicondyles |
Ulna | can't pivot; stabilizing bone; medial & longer in forearm; w/humerus=olecranon (projects proximally from posterior for elbow) & coronoid process (projects anteriorly)>>form walls of trochlear notch; doesn't attach to wrist |
Radius | pivots; lateral & shorter in forearm; proximal end=short head(concave),neck(constriction distal to head),& medially directed tuberosity(distal to medial neck) |
Bones of the Hand | Carpal bones (proximal & distal rows), Metacarpals of the palm, & Phalanges of the fingers/digits |
Carpus (wrist) | 8 bones;
Proximal row (lat>med): Scaphoid, Lunate, Triquetrum, Pisiform
Distal row (lat>med): Trapezium, Trapezoid, Capitate, Hamate |
Scaphoid (G. skaphé, skiff, boat) | a boat-shaped bone that articulates proximally with the radius and has a prominent scaphoid tubercle; it is the largest bone in the proximal row of carpals |
Lunate (L. luna, moon) | a moon-shaped bone between the scaphoid and the triquetral bones; it articulates proximally with the radius and is broader anteriorly than posteriorly |
Triquetrum (L. triquetrus, three-cornered) | a pyramidal bone on the medial side of the carpus; it articulates proximally with the articular disc of the distal radio-ulnar joint |
Pisiform (L. pisum, pea) | a small, pea-shaped bone that lies on the palmar surface of the triquetrum |
Trapezium (G. trapeze, table) | a four-sided bone on the lateral side of the carpus; it articulates with the 1st and 2nd metacarpals, scaphoid, and trapezoid bones |
Trapezoid | a wedge-shaped bone that resembles the trapezium; it articulates with the 2nd metacarpal, trapezium, capitate, and scaphoid bones |
Capitate (L. caput, head) | a head-shaped bone with a rounded extremity and the largest bone in the carpus; it articulates primarily with the 3rd metacarpal distally and with the trapezoid, scaphoid, lunate, and hamate |
Hamate (L. hamulus, a little hook) | a wedge-shaped bone on the medial side of the hand; it articulates with the 4th and 5th metacarpal, capitate, and triquetral bones; it has a distinctive hooked process, the hook of the hamate, that extends anteriorly |
Metacarpus | skeleton of the palm, b/w carpus & phalanges; 5 metacarpal bones; metacarpal=base (proximal & articulate w/carpals), shaft & head (distal & articulate w/proximal phalanges & form knuckles); 1st=thumb (thick/short), 3rd=styloid process |
Phalanges | 3 per digit except for thumb(2); has proximal base/large, shaft(body)/medium, & distal head/small |