1. Chapter 8: The Appendicular Skeleton A&P Biology 141

2. The Appendicular Skeleton
Figure 8–1

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

4. What are the bones of the pectoral girdle, their functions, and features?
Figure 8–2a

5. 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

6. The Clavicles
Figure 8–2b, c

7. The Clavicles Also called collarbones Long, S-shaped bones
Originate at the manubrium (sternal end)
Articulate with the scapulae (acromial end)

8. The Scapulae Also called shoulder blades Broad, flat triangles
Articulate with arm and collarbone

9. The Scapula
Anterior surface: the subscapular fossa
Figure 8–3a

10. Structures of the Scapula
Body has 3 sides:
superior border
medial border (vertebral border)
lateral border (axillary border)
Body has 3 corners:
superior angle
inferior angle
lateral angle

11. Structures of the Scapula
The Scapular Head
Holds glenoid cavity
Which articulates with humerus
To form shoulder joint
Figure 8–3b

12. Processes of the Glenoid Cavity
Coracoid process:
anterior, smaller
Acromion:
posterior, larger
articulates with clavicle
at the acromioclavicular joint

13. Structures of the Scapula
Posterior surface
Posterior Features of the Scapula
Scapular spine:
ridge across posterior surface of body
Separates 2 regions:
supraspinous fossa
infraspinous fossa

14. What are the bones of the upper limbs, their functions, and features?
Arms, forearms, wrists,
and hands
Note: arm (brachium)
1 bone - the Humerus

15. The Humerus Also called the arm The long, upper armbone
Articulates with the pelvic girdle

16. Tubercles of the Proximal Epiphysis
Separated by the intertubercular groove:
greater tubercle:
lateral
forms tip of shoulder
lesser tubercle:
anterior, medial

17. Head and Neck Head: Anatomical neck: Surgical neck:
rounded, articulating surface
contained within joint capsule
Anatomical neck:
margin of joint capsule
Surgical neck:
the narrow metaphysis

18. The Shaft The Distal Epiphysis Deltoid tuberosity: Radial groove:
a bulge in the shaft
attaches deltoid muscle
Radial groove:
for radial nerve
posterior to deltoid tuberosity
The Distal Epiphysis
Medial and lateral epicondyles:
for muscle attachment
Condyle of the humerus:
articulates with ulna and radius

19. Articular Regions of the Condyle
Trochlea:
coronoid fossa and olecranon fossa
articulates with ulna
Capitulum:
radial fossa
articulates with radius

20. The Forearm Also called the antebrachium Consists of 2 long bones:
ulna (medial)
radius (lateral)
Figure 8–5

21. Ulna: The Olecranon Superior end of ulna Point of elbow
Superior lip of trochlear notch
Articulates with trochlea of humerus
Ulna: The Coronoid Process
Inferior lip of trochlear notch

22. Ulna: Articulations with the Humerus
Forearm extended:
olecranon enters olecranon fossa
Forearm flexed:
coronoid process enters coronoid fossa

23. Ulna: Other Articulations
Radial notch:
articulates with head of radius
forms proximal radioulnar joint
Ulnar head:
prominent styloid process
attaches to articular disc between forearm and wrist
Interosseous Membrane
A fibrous sheet
Connects lateral margin of ulnar shaft to radius

24. The Radius Lateral bone of forearm
Disk-shaped radial head above the neck
Radial tuberosity below the neck, attaches biceps

25. Articulations of the Radius
Ulnar notch:
distal end
articulates with wrist and radius
Styloid process:
stabilizes wrist joint

26. The Wrist
Figure 8–6

27. The Wrist 8 carpal bones: 4 proximal carpal bones
4 distal carpal bones
allow wrist to bend and twist

28. The 4 Proximal Carpal Bones
Scaphoid bone:
near styloid process
Lunate bone:
medial to scaphoid
Triquetrum:
medial to lunate bone
Pisiform bone:
anterior to triquetrum

29. The 4 Distal Carpal Bones
Trapezium:
lateral
Trapezoid bone:
medial to trapezium
Capitate bone:
largest
Hamate bone:
medial, distal

30. Metacarpal Bones The 5 long bones of the hand
Numbered I–V from lateral (thumb) to medial
Articulate with proximal phalanges

31. Phalanges of the Hands Pollex (thumb): Fingers:
2 phalanges (proximal, distal)
Fingers:
3 phalanges (proximal, middle, distal)

32. What are the bones of the pelvic girdle, their functions, and features?
Figure 8–7

33. The Pelvic Girdle Made up of 2 hipbones (ossa coxae)
Strong to bear body weight, stress of movement
Part of the pelvis
Os Coxae
Made up of 3 fused bones:
ilium (articulates with sacrum)
ischium
pubis

34. The Acetabulum Also called the hip socket
Is the meeting point of the ilium, ischium, and pubis
Is on the lateral surface of the os coxae
Articulates with head of the femur (lunate surface)
Acetabular Notch
A gap in the ridge of the margins of the acetabulum

35. Marks of the Ilium Greater sciatic notch: for sciatic nerve
Marks of the Ischium
Ischial spine:
above lesser sciatic notch
Ischial tuberosity:
posterior projection you sit on
Ischial ramus:
meets inferior ramus of pubis

36. Marks of the Pubis Superior ramus: Pubic symphysis:
meets pubic tubercle
Pubic symphysis:
gap between pubic tubercles
padded with fibrocartilage

37. Marks of the Pelvic Girdle
Obturator foramen:
formed by ischial and pubic rami
attaches hip muscles
Pectineal line:
ridge of superior ramus of pubis
continues to iliac crest as arcuate line
Iliac fossa:
depression between ileac crest and arcuate line

38. Articulations of the Pelvic Girdle
Sacroiliac joint:
articulation of posterior auricular surface of ilium
with the sacrum
stabilized by ligaments of iliac tuberosity

39. The Pelvis
Figure 8–8

40. The Pelvis Consists of 2 ossa coxae, the sacrum, and the coccyx
Stabilized by ligaments of pelvic girdle, sacrum, and lumbar vertebrae
PLAY
3D Rotation of Pelvis

41. Divisions of the Pelvis
Figure 8–9

42. Divisions of the Pelvis
* True pelvis:
encloses pelvic cavity-
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

43. What are the structural and functional differences between the male and female pelvis?

44. Comparing the Male and Female Pelvis
Figure 8–10

45. Comparing the Male and Female Pelvis
smoother
lighter
less prominent muscle and ligament attachments
PLAY
Male and Female Pelvis

46. Pelvis Modifications for Childbearing
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

47. What are the bones of the lower limbs, their functions, and features?
weight bearing
motion
Note: leg = lower leg; thigh = upper leg

48. Bones of the Lower Limbs
Femur (thigh)
Patella (kneecap)
Tibia and fibula (leg)
Tarsals (ankle)
Metatarsals (foot)
Phalanges (toes)

49. The Femur
The longest, heaviest bone
Figure 8–11

50. Femur: The Proximal Epiphysis
Femoral head:
articulates with pelvis at acetabulum
attaches at fovea capitis
Femur: The Neck
Narrow area between head and trochanters
Joins shaft at angle

51. Femur: Trochanters Femur: The Shaft Greater and lesser trochanters:
tendon attachments
Intertrochanteric line (anterior) and intertrochanteric crest (posterior):
mark edge of articular capsule
Femur: The Shaft
Linea aspera:
most prominent ridge of shaft
attaches hip muscles
joins epicondyles

52. Femur: The Distal Epiphysis
Medial and lateral epicondyles:
above the knee joint
Medial and lateral condyles:
separated by intercondylar fossa and patellar surface
form part of knee joint

53. The Patella
Figure 8–12

54. The Patella Also called the kneecap A sesamoid bone
Formed within tendon of quadriceps femoris
Base attaches quadriceps femoris
Apex attaches patellar ligament

55. The Tibia Also called the shinbone Supports body weight
Larger than fibula
Medial to fibula
Figure 8–13

56. Tibia: The Proximal Epiphysis
Medial and lateral tibial condyles:
separated by intercondylar eminence
articulate with medial and lateral condyles of femur
Tibial tuberosity:
attaches patellar ligament
Tibia: The Shaft
Anterior margin:
sharp ridge of shinbone

57. Tibia: The Distal Epiphysis
Medial malleolus:
medial projection at the ankle

58. The Fibula Attaches muscles of feet and toes Smaller than tibia
Lateral to tibia

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

60. The Ankle Also called the tarsus: consists of 7 tarsal bones
Figure 8–14a

61. Bones of the Ankle Talus: Calcaneus (heel bone): Cuboid bone:
carries weight from tibia across trochlea
Calcaneus (heel bone):
transfers weight from talus to ground
attaches Achilles tendon
Cuboid bone:
articulates with calcaneus

62. Ankle Bones Navicular bone: Medial cuneiform Intermediate cuneiform
articulates with talus and 3 cuneiform bones
Medial cuneiform
Intermediate cuneiform
Lateral cuneiform

63. Feet: Metatarsal Bones
5 long bones of foot
Numbered I–V, medial to lateral
Articulate with toes

64. Feet: Phalanges Phalanges: Hallux: Other 4 toes: bones of the toes
big toe, 2 phalanges (distal, proximal)
Other 4 toes:
3 phalanges (distal, medial, proximal)

65. Feet: Arches Arches transfer weight from 1 part of the foot to another
Figure 8–14b

66. Feet: The Longitudinal Arch
Calcanear portion:
lateral
Talar portion:
Medial
Feet: The Transverse Arch
Formed by a difference in curvature between medial and lateral borders of the foot

67. KEY CONCEPT
Pectoral girdle is highly mobile, stabilized primarily by muscles
Pelvic girdle is more massive, stronger, and less mobile

68. How does the skeleton reveal significant information about an individual?

69. Studying the Skeleton Reveals characteristics:
muscle strength and mass (bone ridges, bone mass)
medical history (condition of teeth, healed fractures)
sex and age (bone measurements and fusion)
body size

70. What are the skeletal differences between males and females?

71. Male and Female Skeletons
Table 8–1

72. How does aging affect the skeletal system?

73. Age-Related Skeletal Changes
Table 8–2

74. SUMMARY (1 of 3) Components of the: appendicular skeleton
pectoral girdle, and relationship to axial skeleton
upper limbs, and relationship to pectoral girdle

75. SUMMARY (2 of 3) Components of the:
pelvic girdle, and relationship to axial skeleton
lower limbs, and relationship to pelvic girdle

76. SUMMARY (3 of 3) Differences between male and female pelvises
Individual skeletal variations
Effects of aging