1. Pectoral Girdle & Upper Limb
Sarah Derman
Irene Park
Tom Raday
Jenn Suh

2. Overview
Part of the appendicular division -bones of the upper and lower limbs
-supporting and connecting bones of the pectoral and pelvic girdles

3. PECTORAL GIRDLE
Two slender, curved clavicles (collarbones) & two broad, flat scapulae
Functions: Position the shoulder joint + provide a base for arm movement
Surfaces of scapulae and clavicles are sites for muscle attachment
-muscles attached to the pectoral girdle help move the arm

4. Clavicle S-shaped Smooth, superior surface lies just beneath the skin
Rough, interior surface of the acromial end has lines and tubules as muscle attachment sites
Right clavicle in a superior view
Acromial end

5. Clavicle
Only direct connections between the axial skeleton and the pectoral girdle
Articulates with the manubrium of the sternum at its strenal end + the acromion (process) of the scapula at its acromial end

6. Clavicle
Small and fragile  fractures are common but heal rapidly without a cast
Ex. Simple fall with outstretched arm
 fractured clavicle
(“broken collarbone”)

7. Scapula Anterior surface of the body of
the scapula forms a triangle bounded by the superior, medial, and lateral borders
-Skeletal muscles support and position the scapula by attaching along these borders (scapula has no bony or ligamentous connection to the thoracic cage)

8. Scapula
Right scapula

9. Scapula
Head of scapula at the intersection of the lateral and superior borders forms a process that supports the shallow, cup-shaped glenoid cavity (glenoid fossa)
-At the glenoid cavity,
the scapula articulates with
the proximal end
of the humerus to form
the shoulder joint

10. Scapula
Right scapula

11. Scapula
Subscapular fossa: Depression in the anterior surface of the body of the scapula
-Subscapularis muscle attaches to the subscapular fossa + to the humerus (the proximal bone of the upper limb)

12. Scapula

13. UPPER LIMB Skeleton = bones of the…
-arm (brachium): from shoulder to elbow; contains a single bone (humerus) that extends from the scapula to the elbow
-forearm (radius and ulna)
-wrist (carpal bones)
-hand
(metacarpal bones
and phalanges)

14. Humerus (Arm) TOP Head articulates with the scapula
Greater tubercle: rounded projection near the lateral surface of the head
-gives shoulder its lateral contour
Lesser tubercule: lies more anteriorly; separated from the greater tubercle by a deep intertubercular groove
Muscles are attached to both tubercules
-large tendon runs along the groove

15. Humerus (Arm) (damage to axillary nerve and artery causes muscles
TOP
Anatomical neck: lies between the tubercules and below the surface of the head
Surgical neck: lies distal to the tubercles
-narrow
-common fracture site
(damage to axillary
nerve and artery
causes muscles
to malfunction)

16. Humerus (Arm) MIDDLE Shaft: round in section
Deltoid tuberosity: runs along the lateral border of the shaft
-deltoid muscle attaches to deltoid tuberosity

17. BOTTOM
Shaft flattens and expands to either side, forming a broad triangle
Medial and lateral epicondyles project to either side
-surface area for muscle attachment
Condyle dominates the inferior surface of the humerus
-at condyle: humermus articulates with the bones of the forearm, the radius, and the ulna
-two distinct regions
1) trochlea: large medial portion
shaped like a spool or pulley
2) capitulum: lateral region of
the condyle
-radial fossa accepts projection
from radius

18. Ulna (Forearm) Ulna=medial support of the forearm
Olecranon: point of the elbow (of ulna)
-trochlear notch articulates with the trochlea of the humerus at the elbow joint;
-limit of the extension (arm + forearm form a straight line)
-limit of flexion (arm + forearm form a V)
Radial notch: lateral to the coronoid process; accomdates the head of the radius
Styloid process: where the ulna ends
-stabilizes the joint by preventing lateral movement of the carpal bones of the wrist

19. Radius (Forearm) Radius=lateral (thumb) side of the forearm
-Fibrous sheet connects the ulna to the radius
Narrow neck extends from the head to the radial tuberosity (attachment site of the biceps brachii)
-head articulates with the capitulum of the humerus at the elbow joint & with radical notch of the ulna  radius rolls across the ulna (rotating palm movement)

20. Wrist and Hand Wrist, palm, fingers: 27 bones
-8 carpal bones (wrist/carpus): scaphoid, lunate, triquetrum pisiform, trapezium, trapezoid, capitates, hamate
-5 metacarpal bones (palm): articulate with
the distal carpal bones
-14 phalangeal bones
(phalange=finger bone): articulate with
the metacarpal bones
-four fingers have three phalanges each
-thumb (pollex) has two phalanges

22. Upper Limb
Upper Limb Disorders (ULDs): affect the arms, from finger to shoulder, and neck
Aches, pains, tension, and disorders
Problems with muscles, tendons, ligaments
Caused or made worse by repetitive, uncomfortable work that involves excessive force
Prevention: exercise, breaks, good posture