Skeletal System: Bone Structure, Functions, and Classification

1. Chapter 5 The Skeletal System

2. Learning Outcomes 1 Describe the parts of a long bone. 2 List the substances that make up bone tissue. 3 List the functions of bones. 4 Identify bones by their classifications. 5 Describe how long bones grow.

3. Learning Outcomes (cont.) 6 List and describe the skeletal structures and one location of each structure. 7 List the bones of the skull, spinal column, rib cage, shoulders, arms, hands, hips, legs, and feet. Describe the location of each bone. 8 Define fontanels and explain their importance.

4. Learning Outcomes (cont.) 9 Describe the three major types of joints and give examples of each. 10 Describe the structure of a synovial joint. 11 Describe the causes, signs and symptoms, and treatments of various diseases and disorders of the skeletal system.

5. Bones provide the body with structure and support 206 bones with 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. The Skeletal System

7. Bone Structure • Bones contain various kinds of tissues, including • Osseous tissue • Blood vessels • Nerves • Osseous tissue can appear compact or spongy

8. Compact bone looks solid Structures can be observed with a microscope All bones are made up of both compact and spongy bone Bone Structure (cont.)

9. Bone Structure (cont.) • Classification by shape • Long bones– located primarily in the arms and legs • Femur (thigh bone) • Humerus (upper arm bone) • Short bones – small bones located in the wrists and ankles • Carpals (wrist bones) • Tarsals (ankle bones)

10. Bone Structure (cont.) • Flat bones – located in the skull and rib cage • Ribs • Frontal bone • Irregular bones • Vertebrae • Bones of the pelvic girdle

11. Male Skull Larger and heavier Forehead shorter Face less round Jaw larger Mastoid processes more prominent Male pelvic bones Heavier and thicker Obturator foramina and acetabula are larger and closer together Bone Structure: Gender Differences

12. Male pelvic cavity Narrower and longer Less roomy and more funnel shaped Male sacrum Narrower Sacral promontory projects forward Sacral curvature is less sharp posteriorly Male coccyx Less movable Bone Structure: Gender Differences (cont.)

13. ANSWER: L Apply Your Knowledge Match bone to classification. ___ Humerus L. Long bones ___ Rib S. Short bones ___ Femur F. Flat bones ___ Pelvic bones I. Irregular bones ___ Carpals ___ Frontal bone ___ Vertebra ___ Tarsals F L Very Good! I S F I S

14. Functions of Bones • Give shape to body parts • Support and protect soft structures • Examples – brain, lungs, heart • Allow body movement, because skeletal muscles attach to them • Allow for voluntary movement

15. Functions of Bones (cont.) • Red bone marrow of bone produces new blood cells – hematopoiesis • Store calcium

16. 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!

17. Bone Growth Ossification – process of bone growth Intramembranous ossification Bones begin as tough, fibrous membrane Bone-forming cells called osteoblasts turn the membrane to bone (located in skull)

18. Bone Growth(cont.) Endochondral ossification Bones begin as cartilage models Primary ossification center Bone formed in the diaphysis Secondary ossification center Epiphyses turn to bone Bones with some cartilage between an epiphysis and the diaphysis will continue to grow Medullary cavity and spaces in cancellous bone form Cells that form holes in bone are called osteoclasts

19. Bone Growth: Building Better Bones Teach healthy behaviors Bone-healthy diet with calcium and vitamin D Bone-health exercises Weight-bearing Strength training Bone-healthy lifestyle Avoid smoking Avoid alcohol

20. Bone Growth(cont.) Bone tests Bone density Bone scans Diagnose causes of Bone pain Arthritis Bone infections Bone cancers

21. 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 of the bone and secondary ossification occurs in the epiphysis. Good Job!

22. Bony Structures Rigid foundation Projections and processes for muscle and ligament attachment Depressions and hollows for articulations – the connection of bones at joints Openings for blood vessels and nerves

23. Bony Structures (cont.)

24. Bony Structures (cont.)

25. “Soft spots” felt on an infant's skull are actually fontanels • Tough membranes that connect the incompletely developed bones The Skull • Two bone types: • Cranial – form the top, sides, and back of the skull • Facial – form the face

26. ANSWER: E Apply Your Knowledge GREAT! 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 C A F B D

27. Frontal – anterior Parietal– top and most of the sides Occipital –back Temporal – form the lower sides of the skull Sphenoid and ethmoid bones – floor Ear ossicles are the smallest bones of the body Malleus Incus Stapes The Skull: Cranial Bones

28. Mandible – forms the lower jaw bone Maxillae – form the upper jawbone Zygomatic – form the prominence of the cheeks Nasal bones – fuse together to form the bridge of the nose Palatine – form the anterior portion of the palate Vomer – a thin bone that divides the nasal cavity The Skull (cont.) Click to see Skull

29. ANSWER: E Apply Your Knowledge 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 floor of skull ___ Maxillae D. Form the prominence of the cheeks ___ Zygomatic E. Back of skull ___ Vomer F. Lower jaw bone C F A Very Good! D B

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

31. Cervical vertebrae Smallest and lightest Located in the neck region First one is atlas Second one is axis Thoracic vertebrae Join the 12 pairs of ribs Lumbar vertebrae Have very sturdy structures The Spinal Column (cont.)

32. The Spinal Column (cont.) • Sacrum • A triangular-shaped bone that consists of five fused vertebrae • Coccyx • A small, triangular-shaped bone made up of 3 to 5 fused vertebrae • Considered unnecessary • More commonly called the tailbone

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

34. The Rib Cage • Sternum • Breastplate • Forms the front middle portion of the rib cage • Joins with the clavicles and most ribs • Xyphoid process • Cartilaginous tip

35. 12 pairs of ribs All are attached posteriorly to thoracic vertebrae True First seven pairs of ribs Attach to sternum by costal cartilage False Rib pairs 8, 9, and 10 Attach to the costal cartilage of rib pair 7 Floating Rib pairs 11 and 12 Do not attach anteriorly to any structure The Rib Cage (cont.)

36. ANSWER: T F cartilaginous F seven F do not attach anteriorly to any structure. Apply Your Knowledge BRAVO! True or False: ___ The sternum forms the front middle portion of the rib cage. ___ The xyphoid 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 xyphoid process. T

37. Bones of the Shoulders, Arms, and Hands • Shoulders – pectoral girdles • Clavicles • Scapulae • Upper limb or arm bones • Humerus • Radius • Ulna

38. Bones of the Shoulders, Arms, and Hands (cont.) • Hand • 8 carpals per hand • 5 metacarpals per hand • 14 phalanges per hand • 3 in each finger • 2 in each thumb

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

40. Bones of the Hips, Legs, and Feet • Hipbones • Coxal bones form the pelvic girdle • Ilium • Ischium • Pubis

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

42. Bones of the Hips, Legs, and Feet (cont.) • Bones of the foot • Tarsals • Metatarsals • Phalanges

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

44. Joints • Junctions between bones • Classification based on structure • Fibrous joints • Connected together with short fibers • Between cranial bones and facial bones • Sutures – fibrous joints in the skull

45. Joints • Cartilaginous joints • Connected together with a disc of cartilage • Between vertebrae

46. Joints • Synovial joints • Covered with hyaline cartilage • Held together by a fibrous joint capsule lined with synovial membrane • Secretes synovial fluid so bones move easily against each other • Freely movable • Bones are also held together through tough, cord-like structures called ligaments

47. 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

48. Arthritis – general term meaning joint inflammation Osteoarthritis – degenerative joint disease, primarily of weight-bearing joints Rheumatoid Arthritis – chronic systemic inflammatory disease of smaller joints and surrounding tissues Common Diseases and Disorders

49. Bursitis – inflammation of a bursa (fluid-filled sac that cushions tendons) Carpal Tunnel Syndrome – overuse of wrist; the median nerve in the wrist becomes compressed Ewing’s Family of Tumors (EFT) – a group of tumors that affect different tissue types; primarily bone Gout – a type of arthritis; deposits of uric acid crystals in the joints Common Diseases and Disorders (cont.)

50. Kyphosis – abnormal curvature of the spine (humpback) Lordosis – exaggerated inward curvature of the lumbar spine (swayback) Osteogenesis imperfecta – brittle-bone disease Osteoporosis – a condition in which bones thin (become porous) over time Common Diseases and Disorders (cont.)