1. Chapter 8: The Appendicular Skeleton

2. Appendicular Skeleton
126 bones
Consists of limbs and limb girdles to provide movement
Pectoral girdle: 4 bones
Upper limbs: 60 bones
Pelvic girdle: 2 bones
Lower limbs: 60 bones

4. Upper limbs Carpal tunnel syndrome
Carpals arranged in two rows of four bones
Creates a U shape enclosed by the flexor retinaculum (ligament)
All tendons, vessels, and nerves of the hand must pass through channels between bones and ligaments (no extra space)
Any inflammation = pressure on nerves leading to pain

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

6. The bones of the pectoral girdle, their functions, and features.

7. The Pectoral Girdle
Figure 8–2a

8. The Pectoral Girdle Also called the shoulder girdle
Connects the arms to the body
Positions the shoulders
Provides a base for arm movement

9. The Pectoral Girdle Consists of:
2 clavicles
2 scapulae
Connects with the axial skeleton only at the manubrium

10. The Clavicles
Figure 8–2b, c

11. The Clavicles Also called collarbones Long, S-shaped bones
Originate at the manubrium (sternal end)
Articulate with the scapulae (acromial end)
Costal Tuberosity:
Attachment for the costoclavicular ligament which articulates with the cartilage of the ribs
Conoid Tubercle:
Attachment for the conoid ligament which articulates with the coracoid process of the scapula

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

13. The Scapula Anterior surface: the subscapular fossa
attachment for the subscapularis muscle
Function to rotate the head of the humerus medially (internal rotation)
Function to draw the humerus forward and downward when the arm is raised
Figure 8–3a

14. Structures of the Scapula
Posterior surface
Supraspinous fossa
Origin for the supraspinatus muscle, which abducts (toward midline) the arm at the shoulder
Origin for the infraspinatus muscle, which adducts that arm
Figure 8–3c

15. Why would a broken clavicle affect the mobility of the scapula?
Muscles attach the clavicle to the scapula.
Clavicle is attached to the sternum which is attached to the scapula.
Clavicle attaches the scapula to the humerus.
Clavicle attaches the scapula to the sternum.

16. The bones of the upper limbs, their functions, and features.

17. The Upper Limbs Arms, forearms, wrists, and hands
Note: arm (brachium) = 1 bone, the humerus

18. The Humerus Also called the arm The long, upper armbone
Greater tuberosity
Attachment for suprasinatus and infrapinatus
Lesser tuberosity
Attachment for tendon of subscapularus
Figure 8–4

19. The Humerus Epicondyle Olecranon fossa Coronoid fossa
Attachment for ligaments of the elbow-joint
Lateral: tendon of supinator muscle
Medial: tendon of flexor muscles of the forearm
Olecranon fossa
Receives process for the extension of the forearm
Coronoid fossa
Receives the coronoid process of the ulna during flexion (joint angle decreases) of the forearm
Figure 8–4

20. The Forearm Also called the antebrachium Consists of 2 long bones:
ulna (medial)
radius (lateral)
Radial Tuberosity
Insertion of bicep brachii
Ulnar Tuberosity
Insertion of brachialis
Styloid Process
Muscle attachment for ulna or radius
Figure 8–5

21. The rounded projections on either side of the elbow are parts of which bone?
humerus
ulna
radius
both A and B

22. Which bone of the forearm is lateral in the anatomical position?
ulna
radius
scaphoid
depends on hand position

23. The Wrist
Figure 8–6

24. Bill accidentally fractures his first distal phalanx with a hammer
Bill accidentally fractures his first distal phalanx with a hammer. Which finger is broken?
thumb
small finger
ring finger
index finger

25. The bones of the pelvic girdle, their functions, and features.

26. The Pelvic Girdle Made up of 2 hipbones (ossa coxae)
Strong to bear body weight, stress of movement
Part of the pelvis

27. Pelvic Girdle 2 os coxae Note:
“pelvis” (no anatomical) = pelvic girdle (2 os coxae) + sacrum + coccyx

28. The Pelvic Girdle
Figure 8–7

29. The Pelvis
Figure 8–8

30. The Pelvis Consists of 2 ossa coxae, the sacrum, and the coccyx
Stabilized by ligaments of pelvic girdle, sacrum, and lumbar vertebrae
Obturator Foramen
Opening for nerves and muscles to pass through
Acetabulum
Head of the femur meets with the pelvis; hip-joint
Ischial Tuberosity
Point of insertion for the semimembranosus, head of biceps femoris, and semitendinosus

31. Which three bones make up the os coxae?
ilium, ischium, and femur
ilium, ischium, and pubis
ilium, acetabulum, and pubis
ilium, femur, and pubis

32. When you are seated, which part of the pelvis bears your body’s weight?
obturator foramen
posterior inferior iliac spines
ischial tuberosities
pubic tubercle

33. Divisions of the Pelvis
Figure 8–9

34. Divisions of the Pelvis
True pelvis:
encloses pelvic cavity
2 regions:
Pelvic brim: encloses pelvic inlet
Perineum region: perineal muscles support organs of pelvic cavity
False pelvis:
blades of ilium above arcuate line

35. The structural and functional differences between the male and female pelvis.

36. Comparing the Male and Female Pelvis
Smoother and lighter
less prominent muscle and ligament attachments

37. Pelvis Modifications for Childbearing
Enlarged pelvic outlet
Broad pubic angle (> 100°)
Less curvature of sacrum and coccyx
Wide, circular pelvic inlet
Broad, low pelvis

38. How is the pelvis of females adapted for childbearing?
narrow pubic angle
greater curvature on sacrum
broad, low pelvis
oval pelvic inlet

39. The bones of the lower limbs, their functions, and features.

40. The Lower Limbs Functions: Note: leg = lower leg; thigh = upper leg
weight bearing
motion
Note: leg = lower leg; thigh = upper leg

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

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

43. Femur Trochanters Shaft: Epicondyle: Greater and lesser trochanters
tendon attachments
Shaft:
attaches hip muscles
Epicondyle:
Lateral and Medial epicondyle
Attachments for ligaments of the knee joint

44. The Patella
Figure 8–12

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

46. The Tibia
Figure 8–13

47. The Tibia Also called the shinbone Supports body weight
Larger than fibula
Medial to fibula
Tibial Tuberosity
Attachment for the
ligamentum patellae

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

49. Fibula helps stabilize the ankle joint.
The fibula neither participates in the knee join nor bears weight. When it is fractured, however, walking becomes difficult. Why?
Fibula helps stabilize the ankle joint.
Fibula attaches many leg muscles.
Both A and B.
None of the above.

50. The Ankle Also called the 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
Figure 8–14a

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

52. talus calcaneus navicular bone first metatarsal bone
While jumping off the back steps at his house, 10-year-old Joey lands on his right heel and breaks his foot. Which foot bone is most likely broken?
talus
calcaneus
navicular bone
first metatarsal bone

53. Which foot bone transmits the weight of the body from the tibia toward the toes?
calcaneus
navicular bone
cuboid bone
talus

54. Which foot bone transmits the weight of the body from the tibia toward the toes?
calcaneus
navicular bone
cuboid bone
talus

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

56. The skeleton reveals significant information about an individual.

57. 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

58. The skeletal differences between males and females.

59. Male and Female Skeletons
Table 8–1

60. How aging affects the skeletal system.

61. Age-Related Skeletal Changes
Table 8–2

62. SUMMARY Components of the:
appendicular skeleton
pectoral girdle, and relationship to axial skeleton
upper limbs, and relationship to pectoral girdle
pelvic girdle, and relationship to axial skeleton
lower limbs, and relationship to pelvic girdle
Differences between male and female pelvises
Individual skeletal variations
Effects of aging