8 PART 1

1. 8 PART 1 Bones, Part 2:The Appendicular Skeleton Pages 185-203

2. The Appendicular Skeleton • Pectoral girdle • Attaches the upper limbs to the trunk • Pelvic girdle • Attaches the lower limbs to the trunk • Upper and lower limbs differ in function • Share the same structural plan

3. The Pectoral Girdle • Consists of the clavicle and the scapula • Provides attachment for many muscles that move the upper limb • Girdle is very light and upper limbs are mobile • Only clavicle articulates with the axial skeleton • Socket of the shoulder joint (glenoid cavity) is shallow • Good for flexibility, bad for stability

4. Articulated Pectoral Girdle Clavicle Acromio- clavicular joint Scapula (a) Articulated pectoral girdle Figure 8.1a

5. Clavicles • Extend horizontally across the superior thorax • Sternal end articulates with the manubrium • Acromial end articulates with scapula • Provide attachment for muscles • Hold the scapulae and arms laterally • Transmit compression forces from the upper limbs to the axial skeleton

6. Sternal (medial) end Posterior Anterior Acromial (lateral) end (b) Right clavicle, superior view Acromial end Anterior Sternal end Trapezoid line Posterior Tuberosity for costoclavicular ligament Conoid tubercle (c) Right clavicle, inferior view Clavicles Figure 8.1b, c

7. Scapulae • Lie on the dorsal surface of the rib cage • Located between ribs 2–7 • Have three borders • Superior • Medial (vertebral) • Lateral (axillary) • Have three angles • Lateral, superior, and inferior

8. Structures of the Scapula Acromion Superior border Suprascapular notch Coracoid process Superior angle Glenoid cavity Subscapular fossa Lateral border Medial border (a) Right scapula, anterior aspect Inferior angle Figure 8.2a

9. Structures of the Scapula Coracoid process Suprascapular notch Acromion Superior angle Supraspinous fossa Glenoid cavity at lateral angle Spine Infraspinous fossa Lateral border Medial border (b) Right scapula, posterior aspect Figure 8.2b

10. The Upper Limb • 30 bones form each upper limb • Grouped into bones of the: • Arm • Forearm • Hand

11. Arm • Region of the upper limb between the shoulder and elbow • Humerus • The only bone of the arm • Longest and strongest bone of the upper limb • Articulates with the scapula at the shoulder • Articulates with the radius and ulna at the elbow

12. Arm • Humerus • Many structures of the humerus provide sites for muscle attachment • Other structures of the humerus provide articulation sites for other bones

13. Structures of the Humerus of the Right Arm Greater tubercle Head of humerus Head of humerus Greater tubercle Lesser tubercle Anatomical neck Anatomical neck Surgical neck Intertubercular sulcus Radial groove Deltoid tuberosity Deltoid tuberosity Medial supracondylar ridge Coronoid fossa Lateral supracondylar ridge Olecranon fossa Radial fossa Medial epicondyle Lateral epicondyle Medial epicondyle Capitulum Trochlea (b) Posterior view Trochlea (a) Anterior view Figure 8.3a, b

14. Structures of the Humerus of the Right Arm Humerus Coronoid fossa Humerus Olecranon fossa Medial epicondyle Capitulum Olecranon process Lateral epicondyle Medial epicondyle Trochlea Head of radius Coronoid process of ulna Head Radial tuberosity Neck Radial notch Radius Ulna Ulna Radius (c) Anterior view at the elbow region (d) Posterior view of extended elbow Figure 8.3c, d

15. Forearm • Formed from the radius and ulna • Proximal ends articulate with the humerus • Distal ends articulate with carpals

16. Forearm • Radius and ulna articulate with each other • At the proximal and distal radioulnar joints • The interosseous membrane • Interconnects radius and ulna • In anatomical position; the radius is lateral and the ulna is medial

17. Ulna • Main bone responsible for forming the elbow joint with the humerus • Hinge joint allows forearm to bend on arm • Distal end is separated from carpals by fibrocartilage • Plays little to no role in hand movement

18. Proximal Part of the Ulna Olecranon process Radial notch of the ulna Olecranon process Head of radius Trochlear notch Head Neck of radius Neck Coronoid process Radial tuberosity Proximal radioulnar joint Interosseous membrane Interosseous membrane Ulna Ulna Radius Ulnar notch of the radius Ulnar notch of the radius Radius Head of ulna Head of ulna Styloid process of ulna Styloid process of radius Distal radioulnar joint Styloid process of ulna (a) Anterior view (b) Posterior view Styloid processof radius Figure 8.4a, b

19. Radius and Ulna Olecranon process Trochlear notch View Coronoid process Radial notch (c) Proximal portion of ulna, lateral view Ulnar notch of radius Articulation for lunate Articulation for scaphoid Styloid process Head of ulna Styloid process View (d) Distal ends of the radius and ulna at the wrist Figure 8.4c, d

20. Radius • Superior surface of the head of the radius articulates with the capitulum • Medially—the head of the radius articulates with the radial notch of the ulna • Contributes heavily to the wrist joint • Distal radius articulates with carpal bones • When radius moves, the hand moves with it

21. Radius and Ulna Humerus Coronoid fossa Humerus Olecranon fossa Medial epicondyle Capitulum Olecranon process Lateral epicondyle Medial epicondyle Trochlea Head of radius Coronoid process of ulna Head Radial tuberosity Neck Radial notch Radius Ulna Ulna Radius (c) Anterior view at the elbow region (d) Posterior view of extended elbow Figure 8.3c, d

22. Hand • Includes the following bones • Carpus—wrist • Metacarpals—palm • Phalanges—fingers

23. Carpus • Forms the true wrist—the proximal region of the hand • Gliding movements occur between carpals • Composed of eight marble-sized bones

24. Carpus • Carpal bones • Are arranged in two irregular rows • Proximal row from lateral to medial • Scaphoid, lunate, triquetrium, and pisiform • Distal row from lateral to medial • Trapezium, trapezoid, capitate, and hamate • A mnemonic to help remember carpals: • Sally left the party to take Carmen home

25. Bones of the Hand Phalanges Distal Middle Proximal Metacarpals Head Sesamoid bones Shaft Base Carpals 4 3 2 5 1 3 4 Carpals 2 Hamate 5 1 Carpals Trapezium Capitate Hamate Trapezoid Pisiform Capitate Scaphoid Triquetrum Triquetrum Lunate Lunate Ulna Radius Ulna (a) Anterior view of right hand (b) Posterior view of right hand Figure 8.6a, b

26. Metacarpus • Five metacarpals radiate distally from the wrist • Metacarpals form the palm • Numbered 1–5, beginning with the pollex (thumb) • Articulate proximally with the distal row of carpals • Articulate distally with the proximal phalanges

27. Phalanges • Except for the thumb, each finger has three phalanges • Proximal, middle, and distal

28. Table 8-1 Bones of the Upper Limb (1 of 3)

29. Table 8-1 Bones of the Upper Limb (2 of 3)

30. Pelvic Girdle • Attaches lower limbs to the spine • Supports visceral organs • Attaches to the axial skeleton by strong ligaments • Acetabulum is a deep cup that holds the head of the femur • Lower limbs have less freedom of movement • Are more stable than the arm

31. Pelvic Girdle • Consists of paired hip bones (coxal bones) • Hip bones unite anteriorly with each other • Articulates posteriorly with the sacrum

32. Bones of the Pelvic Girdle Base of sacrum Iliac crest Sacroiliac joint Iliac fossa Anterior superior iliac spine Sacral promontory llium Coxal bone (os coxae or hip bone) Anterior inferior iliac spine Sacrum Pubis Coccyx Pelvic brim Acetabulum Pubic tubercle Ischium Pubic crest Pubic symphysis (a) Pelvic girdle Pubic arch Figure 8.7a

33. The Pelvic Girdle • Consists of three separate bones in childhood • Ilium, ischium, and pubis • Bones fuse, retain separate names to regions of the coxal bones • Acetabulum • A deep hemispherical socket on lateral pelvic surface

34. Ilium • Large, flaring bone • Forms the superior region of the coxal bone • Site of attachment for many muscles • Articulation with the sacrum forms sacroiliac joint

35. Bones of the Pelvic Girdle Base of sacrum Iliac crest Sacroiliac joint Iliac fossa Anterior superior iliac spine Sacral promontory llium Coxal bone (os coxae or hip bone) Anterior inferior iliac spine Sacrum Pubis Coccyx Pelvic brim Acetabulum Pubic tubercle Ischium Pubic crest Pubic symphysis (a) Pelvic girdle Pubic arch Figure 8.7a

36. Ischium • Forms posteroinferior region of the coxal bone • Anteriorly—joins the pubis • Ischial tuberosities • Are the strongest part of the hip bone

37. Pubis • Forms the anterior region of the coxal bone • Lies horizontally in anatomical position • Pubic symphysis • The two pubic bones are joined by fibrocartilage at the midline • Pubic arch—inferior to the pubic symphysis • Angle helps distinguish male from female pelves

38. Lateral and Medial Views of the Hip Bone Tubercle of the iliac crest Ilium Ilium Ala Anterior gluteal line Iliac fossa Iliac crest Iliac crest Posterior gluteal line Anterior superior iliac spine Anterior superior iliac spine Posterior superior iliac spine Posterior superior iIiac spine Inferior gluteal line Posterior inferior iliac spine Anterior inferior iliac spine Anterior inferior iliac spine Posterior inferior iliac spine Body of the ilium Arcuate line Greater sciatic notch Acetabulum Auricular surface Superior ramus of pubis Ischial body Ischial spine Ischial spine Pubic tubercle Obturator foramen Lesser sciatic notch Pubic body Pubis Ischium Ischium Articular surface of pubis (at pubic symphysis) Ischial tuberosity Ischial ramus Ilium Inferior ramus of pubis Ischium Ischial ramus Inferior ramus of pubis (c) Medial view, right hip bone (b) Lateral view, right hip bone Pubis Figure 8.7b, c

39. True and False Pelves • Bony pelvis is divided into two regions • False (greater) pelvis—bounded by alae of the iliac bones • True (lesser) pelvis—inferior to pelvic brim • Forms a bowl containing the pelvic organs

40. True and False Pelves Plane through midpelvis Anterior abdominal wall False pelvis Pelvic brim, defining pelvic inlet True pelvis Symphyseal surface Coccyx Plane of pelvic outlet (b) True and false pelves Figure 8.8b

41. Pelvic Structures and Childbearing • Major differences between male and female pelves • Female pelvis is adapted for childbearing • Pelvis is lighter, wider, and shallower than in the male • Provides more room in the true pelvis

42. Female and Male Pelves Table 8.2 (1 of 2)

43. Female and Male Pelves Table 8.2 (2 of 2)

44. The Lower Limb • Carries the entire weight of the erect body • Bones of lower limb are thicker and stronger than those of upper limb • Divided into three segments • Thigh, leg, and foot

45. Thigh • The region of the lower limb between the hip and the knee • Femur—the single bone of the thigh • Longest and strongest bone of the body • Ball-shaped head articulates with the acetabulum

46. Structures of the Femur Fovea capitis Neck Greater trochanter Head Inter- trochanteric crest Lesser trochanter Intertrochanteric line Gluteal tuberosity Linea aspera Lateral condyle Medial and lateral supra- condylar lines Lateral epicondyle Intercondylar fossa Medial condyle Lateral epicondyle Adductor tubercle Medial epicondyle Patellar surface (b) Femur (thigh bone) Posterior view Anterior view Figure 8.9b

47. Leg • Refers to the region of the lower limb between the knee and the ankle • Composed of the tibia and fibula • Tibia—more massive medial bone of the leg • Receives weight of the body from the femur • Fibula—stick-like lateral bone of the leg • Interosseous membrane • Connects the tibia and fibula

48. Leg • Tibia articulates with femur at superior end • Forms the knee joint • Tibia articulates with talus at the inferior end • Forms the ankle joint • Fibula does not contribute to the knee joint • Stabilizes the ankle joint

49. Structures of the Tibia and Fibula Figure 8.10a, b

50. The Foot • Foot is composed of • Tarsus, metatarsus, and the phalanges • Important functions • Supports body weight • Acts as a lever to propel body forward when walking • Segmentation makes foot pliable and adapted to uneven ground