Upper limb 1 Flashcards
Pectoral Girdle (2 bones)
Clavicle + Scapula
Function of Pectoral Girdle
Provides attachment for muscles; Provides attachment for the upper limb to the axial skeleton; Provides attachment for the upper limb to the axial skeleton;
Clavicle shape
Medial 2/3rds of the clavicle is convex anteriorly Lateral 1/3rd is concave anteriorly
Clavicle function
o Important muscle attachment site o Act as braces by holding the scapulae and arms out laterally from the thorax. ▪ This becomes obv when a clavicle is fractured – entire shoulder region collapses medially o Transmit compression force from the upper limbs to the axial skeleton
Scapulae location
rib 2 to rib
Scapula 1 Superior boarder 2 Medial border 3 Lateral border
1 short & sharp 2 parallel to the vertebral column 3 thicker, and ends in the glenoid fossa
Scapula 1 Lateral angle 2 Superior angle 3 Inferior angle
1 contains the glenoid fossa 2 superior and medial borders meet, 3 medial and lateral borders meet
Clavicle and scapula attachment point
acromial end + coracoid process
3 fossae of the scapula
supraspinous fossa infraspinous fossa Subscapular fossa
Muscles on scapula (posterior)
Trapezius Levator scapulae Rhomboids
Muscles on scapula (anterior)
Pectoralis minor Serratus anterior Subclavius
Levator scapulae origin
cervical vertebrae
Levator scapulae insertion
medial border of scapula
Levator scapulae action
Elevates scapula and tilts glenoid fossa inferiorly
Levator scapulae Innervation
Dorsal scapular (C5) and cervical nerves (C3-C4)
Trapezius
Origin
superior nuchal line;
external occipital protuberance
nuchal ligament
spinous
processes of C7-T12
Trapezius
Insertion
Lateral 1/3 of clavicle,
acromion, and
spine of scapula
Trapezius Action
upper fibers → elevating scapula
middle fibers → retract scapula
lower fibers → depress scapula
Trapezius Innervation
spinal root of accessory nerve (CN XI and C3, C4)
Rhomboid Origin
Minor: nuchal ligament and spinous processes of C7-T1;
Major: spinous processes of T2-T5
Rhomboid Insertion
Medial border of scapula
Rhomboid Action
Retracts scapula and rotates it to depress the glenoid cavity
Rhomboid Innervation
Dorsal scapular nerve (C4-C5)
Pectoralis minor Origin
3rd to 5th ribs
Pectoralis minor Insertion
Coracoid process of the scapula
Pectoralis minor Action
stabilizes scapula by drawing it inferiorly and anteriorly
Pectoralis minor Innervation
medial pectoral nerve, C8-T1
Serratus Anterior Origin
fleshy slips from upper 8-9 ribs
Serratus Anterior Insertion
costal aspect of medial margin (border) of scapula
Serratus Anterior Action
protracts
stabilizes scapula,
assists with upward rotation
Serratus Anterior Innervation
long thoracic nerve, C5,C6,C7
Rotator Cuff muscles
1) subscapularis,
2) supraspinatus,
3) infraspinatus,
4) teres minor
Rotator cuff that acts to abduct the arm
Supraspinatus
Rotator cuff that inserts into the Lesser Tubercle
Subscapularis
Innervation of Subscapularis
Subscapular nerve
Innervation of Supraspinatus
Subscapular nerve
Innervation of Infraspinatus
Subscapular nerve
Innervation of Teres Minor
Axillary Nerve
Humerus head articulates with
Glenoid fossa
Articulation structure of Humerus for radius
Capitulum
Articulation structure of Humerus to Ulna
Trochlea
