1. Chapter 8: The Appendicular Skeleton

2. The Appendicular Skeleton
Allows us to move and manipulate objects
Includes all bones besides axial skeleton:
the limbs
the supportive girdles

3. The Pectoral Girdle Also called the shoulder girdle
Connects the arms to the body
Positions the shoulders
Provides a base for arm movement
Consists of:
2 clavicles
2 scapulae
Connects with the axial skeleton only at the manubrium
Figure 8–2a

4. The Clavicles Also called collarbones Long, S-shaped bones
Originate at the manubrium (sternal end)
Articulate with the scapulae (acromial end)
Figure 8–2b, c

5. The Scapulae Also called shoulder blades Broad, flat triangles
Articulate with arm and collarbone
Anterior surface-subscapular fossa
Structures
Body
Sides
superior border
medial border (vertebral border)
lateral border (axillary border)
Corners
superior angle
inferior angle
lateral angle

6. Head Holds glenoid cavity Coracoid process-anterior, smaller
Which articulates with humerus to form shoulder joint
Coracoid process-anterior, smaller
Acromion-posterior, larger

7. Scapular spine: ridge across posterior surface of body
Separates 2 regions:
supraspinous fossa
infraspinous fossa

8. The Upper Limbs arms, forearms, wrists, & hands
Humerus-arm
The long, upper armbone
Articulates with the pelvic girdle
Structures
Proximal Epiphysis
separated by intertubercular groove:
greater tubercle:
lateral
forms tip of shoulder
lesser tubercle:
anterior, medial

9. Head: Neck: Shaft rounded, articulating surface
contained within joint capsule
Neck:
Anatomical neck- margin of joint capsule
Surgical neck: the narrow metaphysis
Shaft
Deltoid tuberosity:
a bulge in the shaft
attaches deltoid muscle
Radial groove:
for radial nerve
posterior to deltoid tuberosity

10. Distal Epiphysis Medial and lateral epicondyles:
for muscle attachment
Condyle of the humerus:
Trochlea:
coronoid fossa & olecranon fossa
articulates with ulna
Capitulum:
radial fossa
articulates with radius

11. With radius Ulnar head: articulates with head of radius
forms proximal radioulnar joint
Ulnar head:
prominent styloid process
attaches forearm to wrist

12. The Forearm-antebrachium
Consists of 2 long bones: ulna & radius
Ulna
Articulations
With humerus
Forearm extended: olecranon (elbow point) enters olecranon fossa
Forearm flexed: coronoid process enters coronoid fossa

13. Radius Articulations Ulnar notch: Styloid process: distal end
articulates w/ wrist & radius
Styloid process:
stabilizes wrist joint

14. Wrist 8 carpal bones: allow wrist to bend and twist
4 proximal carpal bones
Scaphoid bone: near styloid process
Lunate bone: medial to scaphoid
Triquetrum: medial to lunate bone
Pisiform bone: anterior to triquetrum
4 distal carpal bones
Trapezium: lateral
Trapezoid bone: medial to trapezium
Capitate bone: largest
Hamate bone: medial, distal

15. Hands 5 Metacarpal Bones Phalanges long bones of the hand
Numbered I–V from lateral (thumb) to medial
Articulate with proximal phalanges
Phalanges
Pollex (thumb):
2 phalanges (proximal, distal)
Fingers:
3 phalanges (proximal, middle, distal)

16. The Pelvic Girdle Hipbones - Os Coxae Made up of 3 fused bones:
ilium
ischium
pubis
Acetabulum - hip socket
meeting point of ilium, ischium, & pubis
on the lateral surface of the os coxae
articulates with head of femur

17. Marks Obturator foramen: Pubic symphysis:
formed by ischial and pubic rami
attaches hip muscles
Pubic symphysis:
gap between pubic tubercles
padded with fibrocartilage

18. The Pelvis Consists of 2 ossa coxae, sacrum, & coccyx
Stabilized by ligaments of pelvic girdle, sacrum, and lumbar vertebrae

19. Divisions of the Pelvis
True Pelvis
Pelvic brim:
upper edge of true pelvis
encloses pelvic inlet
Perineum region:
inferior edges of true pelvis
forms pelvic outlet
perineal muscles support organs of pelvic cavity
False pelvis
blades of ilium above arcuate line

20. Childbearing Modifications
Enlarged pelvic outlet
Broad pubic angle (> 100°)
Less curvature of sacrum and coccyx
Wide, circular pelvic inlet
Broad, low pelvis
Ilia project laterally, not upwards
Due to above, female pelvis is smoother & lighter

21. Lower Limbs Femur Structures Proximal Epiphysis Femoral head: Neck
articulates with pelvis at acetabulum
Neck
narrow area between head & trochanters
Greater & lesser trochanters
tendon attachments

22. Patella - kneecap Shaft Distal Epiphysis A sesamoid bone
Linea aspera:
most prominent ridge of shaft
attaches hip muscles
Distal Epiphysis
Medial & lateral epicondyles:
above the knee joint
Medial & lateral condyles:
form part of knee joint
Patella - kneecap
A sesamoid bone
Base attaches quadriceps femoris
Apex attaches patellar ligament

23. Tibia Structures Proximal Epiphysis Shaft Distal Epiphysis
Medial and lateral tibial condyles
articulate with medial & lateral condyles of femur
Tibial tuberosity: attaches patellar ligament
Shaft
Anterior margin: sharp ridge of shinbone
Distal Epiphysis
Medial malleolus: medial projection at ankle
Figure 8–13

24. Fibula Fibula/tibia articulations: Interosseous membrane:
head
inferior tibiofibular joint
Interosseous membrane:
binds fibula to tibia
Lateral malleolus:
lateral projection of ankle

25. Ankle - tarsus consists of 7 tarsal bones
Talus carries weight from tibia across trochlea
Calcaneus (heel bone): transfers weight from talus to ground & attaches Achilles tendon
Cuboid bone: articulates with calcaneus
Navicular bone: articulates with talus and 3 cuneiform bones
Medial cuneiform
Intermediate cuneiform
Lateral cuneiform
Figure 8–14a

26. Feet 5 metatarsal bones phalanges long bones of foot
numbered I–V, medial to lateral
Articulate with toes
phalanges
bones of the toes
hallux: big toe, 2 phalanges (distal, proximal)
Other 4 toes: 3 phalanges (distal, medial, proximal)
Figure 8–14a

27. Arches Arches transfer weight from 1 part of the foot to another
Longitudinal Arch
Calcanear portion: lateral
Talar portion: medial
Transverse Arch
Formed by a difference in curvature between medial and lateral borders of the foot
Figure 8–14b