The Skeletal System

1. 24 The Skeletal System

2. Learning Outcomes (cont.) 24.1 Describe the structure of bone tissue. 24.2 Explain the functions of bones. 24.3 Compare intramembranous and endochondral ossification. 24.4 Describe the skeletal structures and one location of each structure.

3. Learning Outcomes (cont.) 24.5 Locate the bones of the skull. 24.6 Locate the bones of the spinal column. 24.7 Locate the bones of the rib cage. 24.8 Locate the bones of the shoulders, arms, and hands.

4. Learning Outcomes (cont.) 24.9 Locate the bones of the hips, legs, and feet. 24.10 Describe the three major types of joints and give examples of each. 24.11 Describe the common diseases and disorders of the skeletal system.

5. Bones provide structure and support 206 bones plus joints and connective tissue Divisions Axial~ 80 bones Skull Vertebral column Rib cage Appendicular~ 126 bones Arms and legs Pectoral girdle Pelvic girdle Introduction

6. Bone Structure • Bones contain various kinds of tissues • Osseous tissue • Blood vessels • Nerves • Osseous tissue can appear compact or spongy Spongy (Cancellous)Bone Compact Bone

7. Bone Structure (cont.) • Structures within compact bone • Osteons • Bone matrix • Lamella • Lacunae • Canaliculi • All bones are made up of both compact and spongy bone

8. Bone Structure (cont.) • Long bones • Femur and humerus • Parts • Diaphysis • Epiphysis • Articular cartilage • Medullary cavity • Periosteum • Endosteum

9. Bone Structure (cont.) • Short bones • Flat bones • Irregular bones • Sesamoid bones

10. Male Skull Larger and heavier Forehead shorter Face less round Jaw larger Male pelvis Bones are heavier and thicker Cavity is narrower Gender Differences in Skeletal Structure

11. ANSWER: C Apply Your Knowledge Matching: Holes in the matrix that contain osteocytes Made of inorganic salts, collagen fibers, and proteins; between osteocytes Layers of bone surrounding the canals of the osteons Elongated cylinders that run the length of the bone Canals that connect lacunae to each other • Osteons • Bone matrix • Lamella • Lacunae • Caniculi B D Very Good! A E

12. Functions of Bones • Give shape to body parts • Support and protect soft structures • Function in body movement • Red bone marrow – hematopoiesis • Store calcium

13. Apply Your Knowledge Why is it important for the bones to store calcium? ANSWER: Every cell in the body needs calcium, so the body must have a large supply readily available. Correct!

14. Bone Growth • Ossification • Intramembranous ossification • Bones begin as tough, fibrous membrane • Osteoblasts turn the membrane to bone

15. Bone Growth(cont.) • Endochondral ossification • Bones begin as cartilage models • Diaphysis ~ primary ossification center Diaphysis

16. Bone Growth(cont.) • Endochondral ossification • Epiphysis ~ secondary ossification center • Epiphyseal disc ~ cartilage between epiphysis and diaphysis Diaphysis

17. Building Better Bones • Bone – healthy diet • Vitamin D • Calcium • Bone-healthy exercises • Weight-bearing • Strength-training

18. Building Better Bones (cont.) • Bone-healthy lifestyle – avoid smoking and alcohol • Bone tests • Bone density tests • Bone scan

19. Apply Your Knowledge What are the two types of bone growth? ANSWER: Intramembranous ossification, in which bones begin as tough membrane and are turned to bone by osteoblasts, and endochondral ossification, in which primary ossification occurs in the diaphysis of the bone and secondary ossification occurs in the epiphysis. Good Job!

20. Bony Structures • Bones are designed with • Projections and processes • Depressions and hollows at articulations • Openings for blood vessels and nerves

21. Bony Structures (cont.)

22. Bony Structures (cont.)

23. Apply Your Knowledge GREAT! ANSWER: Match the following: ___ Epicondyle A. A relatively deep pit or depression ___ Fontanels B. An interlocking line of union between bones ___ Fossa C. “Soft spots” felt on an infant’s skull ___ Process D. A knoblike process, usually larger than a tubercle ___ Suture E. A projection situated above a condyle ___ Tuberosity F. A prominent projection on a bone E C A F B D

24. The Skull • Two bone types – cranial and facial • Infant skulls • Bones not completely formed • Fontanels – tough membranes • Sutures

25. Cranial bones Frontal Parietal Occipital Temporal External auditory meatus Sphenoid and ethmoid bones Ear ossicles Malleus Incus Stapes The Skull (cont.) Click to see Skull

26. The Skull (cont.) • Facial bones • Mandible ~ lower jaw • Maxillae ~ upper jaw • Zygomatic • Cheekbones • Fused nasal bones form bridge of nose • Palatine ~ hard palate • Vomer ~ divides nasal cavity Click to see Skull

27. Apply Your Knowledge ANSWER: Match the bones of the skull: ___ Occipital A. Form the upper jawbone ___ Sphenoid B. A thin bone that divides the nasal cavity ___ Mandible C. Part of the floor of the skull ___ Maxillae D. Form the prominence of the cheeks ___ Zygomatic E. Back of skull ___ Vomer F. Lower jawbone E C F A D Very Good! B

28. The Spinal Column • 7 cervical vertebrae • 12 thoracic vertebrae • 5 lumbar vertebrae • Sacrum • Coccyx

29. The Spinal Column (cont.) • Cervical vertebrae • Smallest and lightest • Located in the neck • Atlas • Axis • Thoracic vertebrae • Posterior attachment for ribs • Lumbar vertebrae • Small of the back • Bear most weight

30. The Spinal Column (cont.) • Sacrum • A triangular-shaped bone • Five fused vertebrae • Coccyx • A small, triangular-shaped bone • 3 to 5 fused vertebrae

31. Apply Your Knowledge ANSWER: Cervical – 7 Identify the sections of the spinal column and give the number of vertebrae for each. Thoracic – 12 Lumbar – 5 Right! Sacrum – 5 fused Coccyx – 3 to 5 fused

32. The Rib Cage • Sternum • Breastplate • Joins with the clavicles and most ribs • Xiphoid process To ribcage

33. The Rib Cage (cont.) • Ribs • All are attached posteriorly to thoracic vertebrae • True – 1st 7 pairs • False – pairs 8, 9, and 10 • Floating – pairs To ribcage

34. The Rib Cage (cont.) Back

35. Apply Your Knowledge BRAVO! ANSWER: True or False: ___ The sternum forms the front middle portion of the rib cage. ___ The xiphoid process is a boney tip of the sternum. ___ The true ribs are the first five pairs of ribs. ___ False ribs attach to the costal cartilage of rib pair seven. ___ Floating ribs attach to the xiphoid process. T F cartilaginous F seven T F do not attach anteriorly to any structure.

36. Bones of the Shoulders, Arms, and Hands • Shoulders • Clavicles ~ collar bones • Scapulae~ shoulder blade • Arm bones • Humerus • Radius • Ulna

37. Bones of the Shoulders, Arms, and Hands(cont.) • Hand • Carpals ~ 8 • Metacarpals ~ 5 • Phalanges ~ 14 • 3 per finger • 2 per thumb

38. Apply Your Knowledge ANSWER: Match the following: ___ Clavicle A. Pectoral girdle ___ Radius B. Arm bones ___ Humerus C. Hands ___ Carpals ___ Scapula ___ Ulna ___ Phalanges ___ Metacarpals A B B Excellent! C A B C C

39. Bones of the Hips, Legs, and Feet • Hip bones • Coxal bones • Ilium • Ischium • Pubis

40. Bones of the Hips, Legs, and Feet (cont.) • Bones of leg • Femur • Patella • Tibia • Fibula

41. Bones of the Hips, Legs, and Feet (cont.) • Bones of the foot • Tarsals ~ 7 • Metatarsals ~ 5 • Phalanges ~ 14 • 3 per toe • 2 per each big toe

42. Apply Your Knowledge ANSWERS: Match the following: A. Coxal bones B. Leg bones C. Foot bones ___ Tibia ___ Patella ___ Ilium ___ Ischium ___ Femur ___ Metatarsals ___ Pubis ___ Fibula ___ Calcaneus ___ Tarsals B B A A B C A B C C Super!

43. Joints • Junctions between bones • Fibrous joints • Connected together with short fibers • Between cranial bones and facial bones • Sutures

44. Joints (cont.) • Cartilaginous joints • Disc of cartilage • Slightly moveable • Between vertebrae

45. Joints (cont.) • Synovial joints • Covered with hyaline cartilage • Fibrous joint capsule  • Freely movable • Ligaments hold bones together

46. ANSWER: A Apply Your Knowledge Match the following: A. Fibrous joints B. Cartilaginous joints C. Synovial joints ____ Between cranial bones and facial bones ____ Covered with hyaline cartilage ____ Between vertebrae ____ Freely movable ____ Sutures in the skull C B Yippee! C A

47. Common Diseases and Disorders of the Skeletal System • Arthritis • Osteoarthritis • Degenerative joint disease (DJD) • Weight-bearing joints • Rheumatoid arthritis • Chronic systemic inflammatory disease • Smaller joints and surrounding tissues

48. Common Diseases and Disorders of the Skeletal System (cont.) • Bursitis – inflammation of the bursa • Ewing sarcoma family of tumors (ESFT) • Primarily affect bone • Usually lower extremities • Gout – deposits of uric acid crystals in joints

49. Common Diseases and Disorders of the Skeletal System (cont.) • Kyphosis – humpback • Lordosis –swayback • Osteogenesis imperfecta – brittle-bone disease • Osteoporosis – thin, porous bones

50. Common Diseases and Disorders of the Skeletal System (cont.) • Osteosarcoma – bone cancer from osteoblasts • Paget’s disease – bones enlarge, become deformed, and weak • Scoliosis – an abnormal S-shaped curvature of the spine