Skeletal - Appendicular (235 #8) Flashcards
Pectoral/Shoulder Girdle
Attach the bones of the upper limbs to the axial skeleton. Do not articulate with the vertebra – are held in place & stabilized with muscles that extend from vertebrae and ribs to scapula.
1) clavicle – anterior bone articulates with the manubrium of the sternum
2) scapula – posterior bone articulates with the clavicle at the acromioclavicular joint and with the humerus at the glenohumeral joint.
Clavicle
S-shaped bone, rougher and more curved in males. Transmits mechanical force from the upper limb to the trunk. One of the most frequently broken bones.
1) sternal end – articulates with manubrium
2) acromial end – articulates with acromium of scapula
3) conoid tubercle – inferior surface of lateral end, for attaching conoid ligament btwn scapula and clavicle.
4) Impression for costoclavicular ligament – attaches clavicle to first rib.
Scapula
Large triangular flat bone in superior posterior thorax btwn R2-R7.
1) spine – prominent ridge across posterior, lateral flattened expanded process is ACROMION – high point of shoulder (acromioclavicular joint)
2) Glenoid cavity – shallow depression inferior to acromion, accepts head of humerus (glenohumeral joint)
3) Inferior angle – point at bottom of scapula
4) Superior angle – along the superior border.
5) Scapular notch – prominent indentation in superior border for suprascapular nerve
6) Coracoid process – tendons of muscles (pectoralis minor, coracobrachialis and biceps brachii) and ligaments (coracoacromial, conoid, trapezoid) attach.
7) Supraspinous Fossa & Infraspinous Fossa – superior and inferior to spine, for same name muscle attachment.
8) Subscapular Fossa – on anterior of scapula for subscapularis muscle.
Upper Limb (Extremity)
30 bones in 3 locations
1) humerus
2) ulna and radius
3) 8 carpals in wrist, 5 metacarpals in the metacarpus (palm) and 14 phalanges
Humerus - Proximal
Longest and largest bone of the upper limb
1) head – proximal end that articulates with glenoid cavity of scapula
2) anatomical neck – distal to head, visible as oblique groove. Former site of epiphyseal plate
3) greater tubercle – lateral projection distal to neck, most laterally palpable bony landmark
4) lesser tubercle – projects anteriorly. Btwn two tubercles is intertubercular sulcus.
5) Surgical neck – constriction in shaft just distal to tubercles, where fractures often occur
6) Shaft – starts cylindrical, ends up triangular, flattened and broad.
7) Deltoid tuberosity – middle of shaft, roughened V-shape
Humerus - Distal
8) Radial groove – contains radial nerve
9) Capitulum – rounded knob that articulates with radius
10) Radial fossa – anterior depression above the capitulum that articulates with the head of the radius when the forearm is bent.
11) Trochlea – medial to the capitulum, spool-shaped that articulates with trochlear notch of the ulna
12) coronoid fossa – receives coronoid process of ulna when forearm is flexed
13) olecranon fossa – receives olecranonon of ulna when forearm is straight
14) Medial & lateral epicondyle – rough projections for tendon attachment
15) ulnar nerve – can be palpated over medial condyle – FUNNY BONE
ULNA – Proximal to Distal
Located on the medial aspect (little finger side) of the forearm and is longer than the radius. P.U. = Pinky is on the Ulna side
1) olecranon – forms the prominence of the elbow
2) coronoid process – articulates with the trochlea of the humerus – the trochlear notch is the curved area between olecranon and coronoid process that forms part of the elbow joint
3) radial notch – articulates with the head of the radius
4) ulnar tuberosity – where the biceps brachii tendon attaches
5) head (distal) – separated from the wrist by layer of fibrocartilage
6) styloid process – attachment for the ulnar collateral ligament to the wrist
Radius – Proximal to Distal
Smaller bone of the forearm, narrow at it’s proximal end and widens at the distal end.
1) head – disc-shaped, articulates with capitulum of humerus and radial notch of ulna
2) neck – constricted, inferior to head
3) radial tuberosity – roughened area for attachment of biceps brachii
4) styloid process – can be felt proximal to the thumb, attachment for brachioradialis and radial collateral ligament to the wrist.
Fracture of the distal end of the radius is the most common fracture in +50yr olds
Interosseus Membrane
Joins the shaft of the radius & ulna – broad flat connective tissue. Site of attachment for some tendons of deep skeletal muscles of the forearm.
Elbow
1) head of radius with capitulum of humerus
2) trochlear notch of ulna articulates with the trochlea of the humerus
Proximal Radioulnar Joint
Head of radius articulates with ulna’s radial notch
Distal Radioulnar Joint
Head of ulna articulates with radius’s ulnar notch
Head of ulna articulates with radius’s ulnar notch
Distal end of radius articulates with three bones of the wrist = lunate, scaphoid and triquetrum.
Carpus/Wrist
Consists of 8 carpals joined by intercarpal joints = two traverse rows of 4 bones
Proximal, lateral to medial
1) scaphoid = boatlike, 70% of carpal fractures
2) lunate = moon-shaped
3) triquetrum = three-cornered
4) pisiform = pea-shaped
Distal, lateral to medial
5) Trapezium = 4-sided figure
6) Trapezoid = 4-sided, 2 sides parallel
7) Capitate = head-shaped, largest carpal bone
8) Hamate = hooked projection on anterior surface
Stop Letting Those People Touch The Cadaver’s Hand
Carpal Tunnel = formed by pisiform and hamate, scaphoid and trapezium with roof of flexor retinaculum.
Metacarpus/Palm
Intermediate region of the hand, consists of 5 (I-V) metacarpals.
1) Proximal = base, carpometacarpal joins
2) Shaft
3) Distal = head (knuckles), metacarpophalangeal joints
Thumb = I, Pinky = V
Phalanges - Hand
14 phalanges with interphalangeal joints. (I-V) = proximal, middle and distal rows
Thumb (pollex) has no middle row.