1. Chapter 8: The Appendicular Skeleton
BIO 210 Lab
Instructor: Dr. Rebecca Clarke

2. Appendicular Skeleton
Allows us to move and manipulate objects
Includes all bones besides axial skeleton:
the limbs
the supportive girdles
Pectoral (shoulder)
Pelvic

3. Appendicular Skeleton
Figure 8–1

4. Pectoral Girdle Also called the shoulder girdle
Positions shoulder joints
Connects the arms to the body
Provides base for muscle attachment
Helps move upper limbs

5. Pectoral Girdle
Figure 8–2a

6. Pectoral Girdle Consists of:
2 clavicles
2 scapulae
Connects with axial skeleton only at the manubrium (clavicle articulations)

7. Clavicle Also called collarbone Long, S-shaped bone
Originates at manubrium (sternal end)
Articulates with scapula (acromial end)
Relatively fragile so fractures common

8. Clavicle Sternal End: Acromial End: Square, flat surface
Articulates with manubrium; only ones between axial skeleton and pectoral girdle
Acromial End:
Flatter, broader end
Articulates with acromion of scapula
Figure 8–2b, c

9. Scapula Also called shoulder blade Broad, flat triangle
Articulates with arm and collarbone
Skeletal muscles support/position 
Extreme mobility
Not much strength

10. Scapula: Posterior Surface
Body
Broad, flat, triangular area
Has 3 borders/ margins
Superior
Medial
Lateral
Figure 8–3c

11. Scapula: Posterior Surface
Spine
Large ridge across posterior surface
Shoulder blade
Supraspinous fossa
Depression superior to spine
Infraspinous fossa
Depression inferior to spine
Figure 8–3c

12. Scapula: Posterior Surface
Acromion
Large, posterior extension at lateral end of spine
Articulates with clavicle (acromial end)
Figure 8–3c

13. Scapula: Lateral View Glenoid fossa (cavity)
Cup-shaped, lateral depression
Articulates with humerus
Forms shoulder joint
Figure 8–3c

14. Scapula: Lateral View Coracoid process
Smaller, anterior projection superior to glenoid cavity
Near clavicle vs coronoid process on mandible near nose)
Figure 8–3c

15. Scapula: Anterior Surface
Subscapular fossa
Depression on smooth, anterior side of body
Figure 8–3a

16. Bones of the Upper Limbs
Brachium (arm)
Antebrachium (forearm)
Ulna
Radius
Carpals (wrist)
Metacarpals (hand)
Phalanges (fingers)

17. Humerus Only bone in brachium (arm) Extends from scapula to elbow
Articulates with pectoral girdle
on proximal end (head) – with glenoid fossa of scapula
on distal end – with radius and ulna (bones of antebrachium)

18. Humerus Head Greater tubercle Lesser tubercle Intertubercular groove
Large, ball-shaped structure on proximal end
Greater tubercle
Larger, rounded projection on lateral/posterior surface of epiphysis
Lesser tubercle
Smaller projection on medial/anterior surface
Intertubercular groove
Separates tubercles
Figure 8–4

19. Humerus Anatomical neck Surgical neck Deltoid tuberosity
Narrow groove between base of head and tubercles
Margin of joint capsule
Surgical neck
At metaphysis
Where fractures often occur
Deltoid tuberosity
Rough ridge on-anterior surface of shaft
Where deltoid muscle attaches
Figure 8–4

20. Humerus Condyle = rounded projection for muscle attachment
Distal epiphysis where humerus articulates with radius and ulna
“Knuckles” on anterior surface of humerus
Figure 8–4

21. Humerus Lateral epicondyle Medial epicondyle
More prominent than lateral one
Trochlea (“pulley” or “spool”)
In center of condyle (middle “knuckle)
Where trochlear notch of ulna rotates during forearm flexion
Capitulum
Forms a “cap” over the radius
Figure 8–4

22. Humerus Coronoid fossa Olecranon fossa On anterior surface
Articulates with coronoid process of ulna
Olecranon fossa
On posterior surface
Articulates with olecranon of ulna
Figure 8–4

23. Antebrachium (Forearm)
Consists of 2 long bones:
Ulna (medial)
Radius (lateral)
“Rotates”
Site of radial pulse
Figure 8–5

24. Ulna Olecranon (process)
Large, curved projection (like cobra head) on proximal end
“U” for ulna
Articulates in olecranon fossa of humerus
Superior lip of trochlear notch
Point of elbow
Figure 8–5

25. Ulna Trochlear notch Coronoid process
Anterior curved surface of proximal epiphysis
Articulates with trochlea of humerus
Coronoid process
Inferior lip of trochlear notch
Articulates in coronoid fossa of humerus
Figure 8–5

26. Ulna Head Styloid process Much smaller, distal epiphysis (near wrist)
Articulates with radium and carpal (wrist) bones
Styloid process
Medial pointed extension at distal epiphysis
On posterior, lateral surface of head
Figure 8–5

27. Ulna: Articulations with the Humerus
Forearm extended:
Olecranon enters olecranon fossa
Forearm flexed:
Coronoid process enters coronoid fossa

28. Radius Head Neck Radial tuberosity Disc-shaped proximal epiphysis
Articulates with humerus
Neck
Narrow region between head and tuberosity
Radial tuberosity
Structure at proximal end of diaphysis below neck
Marks attachment site of biceps brachii muscle
Figure 8–5

29. Radius Shaft Styloid process Curves and broadens
Distal portion much larger than distal portion of ulna
Styloid process
Lateral pointed extension at distal epiphysis
Stabilizes wrist joint
Figure 8–5

30. Carpal Bones Allow wrist to bend and twist 8 bones
“Sam likes to push the toy car hard.”

31. Carpal Bones Scaphoid Lunate Triquetrum Pisiform Trapezium Trapezoid
Capitate
Hamate

32. Wrist and Hand Bones
Figure 8–6

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

34. Phalanges (Phalanx=singular)
Finger bones
I (lateral)
Pollex (thumb):
2 phalanges (proximal, distal)
II - V
3 phalanges (proximal, medial or middle, distal)

35. Pelvic Girdle Functions
Weight-bearing
Locomotion
Bones more massive than those of pectoral girdle
Strong to bear body weight

36. Pelvic Girdle Made up of 2 hip bones (coxal bones or pelvic bones)
Each hip bone is made up of 3 fused bones:
Ilium (articulates with sacrum)
Ischium
Pubis

37. Pelvic Girdle
Figure 8–7

38. Pelvic Girdle: Ilium Largest hip bone Superior part of coxae
Fused to ischium (posteriorly) and pubis (anteriorly)
Articulates with sacrum – attaches pelvic girdle to axial skeleton
Figure 8–7

39. Pelvic Girdle: Ilium Iliac crest Anterior superior iliac spine (ASIS)
Superior border
Anterior superior iliac spine (ASIS)
Anterior inferior iliac spine (AIIS)
Posterior superior iliac spine (PSIS)
Posterior inferior iliac spine (PIIS)
Figure 8–7

40. Pelvic Girdle: Ilium Iliac fossa Sacroiliac joint
Depression on anterior aspect
Sacroiliac joint
Between posterior superior and inferior spines; where ilium and sacrum articulate
Greater sciatic notch
Inferior to PIIS
Passageway for large sciatic nerve
Figure 8–7

41. Pelvic Girdle: Ischium
Posterior-inferior part of coxae
Ischial spine
Inferior to greater sciatic notch
At posterior-superior end
Lesser sciatic notch
Inferior to ischial spine
Ischial tuberosity
Thickened posterior-inferior part
Bears body weight when seated (“sit bone”)
Figure 8–7

42. Pelvic Girdle: Pubis Anterior-inferior part of coxae Pubic symphysis
Joint where anterior medial surfaces of pubic bones are interconnect by fibrocartilage pad
Limits movement between pubic bones of left and right hipbones
Figure 8–7

43. Pelvic Girdle: Acetabulum
Also called the hip socket
Large, concave socket on lateral surface of os coxae
Meeting point of ilium, ischium, and pubis
Articulates with head of femur
Figure 8–7

44. Pelvic Girdle: Obturator Foramen
Large space encircled by pubis and ischium
Closed by sheet of collagen fibers
Provides base for hip muscles
Figure 8–7

45. Pelvis
Consists of:
2 hip bones
Sacrum
Coccyx (of axial skeleton)
Stabilized by ligaments of pelvic girdle, sacrum, and lumbar vertebrae

46. Pelvis
Figure 8–8

47. Pelvic Openings
Pelvic inlet – (anterior) space enclosed by pelvic brim
Pelvic outlet – opening bounded by coccyx and ischial tuberosities
Figure 8–9

48. Pubic Angle
Inferior angle between pubic bones
Figure 8–10

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

50. Femur Longest, heaviest bone Transfers body weight to ground
Articulates with:
coxae at acetabulum
tibia at knee joint
Figure 8–11

51. Femur Head Neck Large, round proximal end Articulates at acetabulum
Narrow connector between head and shaft
Joins shaft at angle
Figure 8–11

52. Femur Greater trochanter Lesser trochanter
Large process at superior end of shaft
Lesser trochanter
Smaller process inferior to neck on medial /posterior side
Figure 8–11

53. Femur Lateral condyle Medial condyle
Large, rounded, lateral projection at distal epiphysis
Articulates with lateral condyle of tibia
Medial condyle
Large, rounded, medial projection at distal epiphysis
Articulates with medial condyle of tibia
Figure 8–11

54. Femur Intercondylar fossa
Depression between condyles on posterior side
Figure 8–11

55. Femur Patellar surface
Flattened area between condyles on anterior side
Figure 8–11

56. Patella Large sesamoid bone
Forms within tendon of quadriceps femoris (extends/straightens the knee)
Figure 8–12

57. Tibia Larger, medial bone; supports body weight
Also called the shinbone
Figure 8–13

58. Tibia Lateral condyle Medial condyle
Lateral projection at proximal epiphysis
Articulates with lateral condyle of femur
Medial condyle
Medial projection at proximal epiphysis
Articulates with medial condyle of femur
Figure 8–13

59. Tibia Tibial tuberosity Roughened area on anterior surface
Inferior to condyles
Attachment for patellar ligament
Figure 8–13

60. Tibia Anterior margin Medial malleolus (“little mallet”)
Ridge that begins at tibial tuberosity and extends distally along anterior surface (“shin bone”)
Medial malleolus (“little mallet”)
Projection on medial side at distal epiphysis
Figure 8–13

61. Fibula
Slender, lateral bone of lower leg
Figure 8–13

62. Fibula Head Lateral malleolus Articulates with proximal tibia
Projection on lateral side at distal epiphysis
Articulates with distal tibia
Provides lateral stability to ankle
Figure 8–13

63. Tarsal Bones
Allow ankle to bend and twist
7 bones

64. Ankle and Foot Bones
Figure 8–14a

65. Tarsal Bones Talus Calcaneous Navicular Cuboid Cuneiforms (3)
Note: movement more restricted than wrist/hand

66. Metatarsal Bones 5 long bones of the foot
Numbered I–V from medial (big toe) to lateral
Articulate with proximal phalanges

67. Phalanges Toe bones I (lateral) II - V Hallus (big toe):
2 phalanges (proximal, distal)
II - V
3 phalanges (proximal, medial or middle, distal)