Chapter 5 - The Skeletal System
- 1. CHAPTER 5 THE SKELETAL SYSTEM
- 2. The Skeletal System Parts of the skeletal system Bones (skeleton) Joints Cartilages Ligaments (bone to bone)(tendon=bone to muscle)
- 3. The Skeletal System Divided into two divisions Axial skeleton Appendicular skeleton – limbs and girdle
- 4. Axial Skeleton • Consists of 80 bones along the central axis of the human body • It is composed of six parts; the skull, the ossicles (in middle ear), the hyoid bone, the rib cage, the sternum, and the vertebral column
- 5. Appendicular Skeleton • Composed of 126 bones in the human body • Appendicular is an adjective derived from the noun appendage • This means that these structures are joined to something larger
- 8. Functions of Bones 1. Support of the body 2. Protection of soft organs 3. Movement due to attached skeletal muscles 4. Storage of minerals and fats 5. Blood cell formation
- 9. Functions of Bones • 1. Support of the body – Internal framework that supports the body and cradles its soft organs • 2. Protection of soft organs – Ex. skull – brain, rib cage – lungs and heart
- 10. Functions of Bones • 3. Movement due to attached skeletal muscles – Skeletal muscles attached by tendons use the bones as levers to move the body and its parts • 4. Storage of minerals and fats – Fat is stored in the internal cavities of bone – Stores minerals such as calcium and phosphorus
- 11. Functions of Bones • 5. Blood cell formation – Hematopoiesis – Occurs within the marrow cavities of certain bones
- 12. Bones of the Human Body The skeleton has 206 bones Two basic types of bone tissue Compact bone Homogeneous Spongy bone Small needle-like pieces of bone Many open spaces Figure 5.2b
- 13. Classification of Bones on the Basis of Shape Figure 5.1
- 14. Classification of Bones Long bones Typically longer than they are wide Have a shaft with heads at both ends Contain mostly compact bone • Examples: Femur, humerus
- 15. Classification of Bones Short bones Generally cube- shape Contain mostly spongy bone Examples: Carpals, tarsals
- 16. Classification of Bones Flat bones Thin and flattened Usually curved Thin layers of compact bone around a layer of spongy bone Examples: Skull, ribs, sternum
- 17. Classification of Bones Irregular bones Irregular shape Do not fit into other bone classification categories Example: Vertebrae and hip
- 18. Gross Anatomy of a Long Bone Diaphysis Shaft Composed of compact bone Epiphysis Ends of the bone Composed mostly of spongy bone Figure 5.2a
- 19. Gross Anatomy of a Long Bone
- 20. Structures of a Long Bone Periosteum Outside covering of the diaphysis Fibrous connective tissue membrane Sharpey’s fibers Secure periosteum to underlying bone Arteries Supply bone cells with nutrients Figure 5.2c
- 21. Structures of a Long Bone
- 22. Structures of a Long Bone Articular cartilage Covers the external surface of the epiphyses Made of hyaline cartilage Decreases friction at joint surfaces Figure 5.2a
- 23. Structures of a Long Bone Medullary cavity Cavity of the shaft Contains yellow marrow (mostly fat) in adults Contains red marrow (for blood cell formation) in infants Figure 5.2a
- 24. Bone Marrow
- 27. Bone Markings - Page 138 Slide 5.9 Surface features of bones Sites of attachments for muscles, tendons, and ligaments Passages for nerves and blood vessels Categories of bone markings Projections and processes – grow out from the bone surface Depressions or cavities – indentations
- 29. Microscopic Anatomy of Bone Osteon (Haversian System) A unit of bone Central (Haversian) canal Opening in the center of an osteon Carries blood vessels and nerves Perforating (Volkman’s) canal Canal perpendicular to the central canal Carries blood vessels and nerves
- 31. Microscopic Anatomy of Bone Figure 5.3
- 32. Microscopic Anatomy of Bone Lacunae Cavities containing bone cells (osteocytes) Arranged in concentric rings Lamellae Rings around the central canal Sites of lacunae Figure 5.3
- 33. Microscopic Anatomy of Bone Canaliculi Tiny canals Radiate from the central canal to lacunae Form a transport system Figure 5.3
- 34. Changes in the Human Skeleton In embryos, the skeleton is primarily hyaline cartilage During development, much of this cartilage is replaced by bone Cartilage remains in isolated areas Bridge of the nose Ears Parts of ribs Joints
- 35. Bone Growth Epiphyseal plates allow for growth of long bone during childhood New cartilage is continuously formed Older cartilage becomes ossified Cartilage is broken down Bone replaces cartilage
- 37. Bone Growth Bones are remodeled and lengthened until growth stops Bones change shape somewhat Bones grow in width
- 38. Long Bone Formation and Growth Figure 5.4a
- 39. Types of Bone Cells Osteocytes Mature bone cells Osteoblasts Bone-forming cells Osteoclasts Bone-destroying cells Break down bone matrix for remodeling and release of calcium Bone remodeling is a process by both osteoblasts and osteoclasts
- 41. Bone Fractures A break in a bone Types of bone fractures Closed (simple) fracture – break that does not penetrate the skin Open (compound) fracture – broken bone penetrates through the skin Bone fractures are treated by reduction and immobilization Realignment of the bone
- 42. Common Types of Fractures Table 5.2
- 43. Repair of Bone Fractures • 1.Inflammation - Hematoma (blood-filled swelling) is formed • Begins immediately after the injury and lasts up to 5 days
- 44. Repair of Bone Fractures • 2. Soft callus formation - Break is splinted by fibrocartilage to form a callus • Begins anywhere from 4 day to 3 weeks after injury, lasts about 6 weeks
- 45. Repair of Bone Fractures • 3. Hard callus formation - Fibrocartilage callus is replaced by a bony callus • Lasts 6-12 weeks; 6 for upper limbs, 12 for lower limbs
- 46. Repair of Bone Fractures • 4. Bone remodeling - Bony callus is remodeled to form a permanent patch • Can continue for several years
- 47. Stages in the Healing of a Bone Fracture Figure 5.5
- 48. The Axial Skeleton Forms the longitudinal part of the body Divided into six parts Skull Ossicles Hyoid bone Vertebral column Rib cage Sternum
- 49. The Axial Skeleton Figure 5.6
- 50. The Skull Two sets of bones Cranium Facial bones Bones are joined by sutures Only the mandible is attached by a freely movable joint
- 52. Bones of the Skull Figure 5.11
- 53. Human Skull, Superior View Figure 5.8
- 54. Human Skull, Inferior View Figure 5.9
- 55. Paranasal Sinuses Hollow portions of bones surrounding the nasal cavity Figure 5.10
- 56. Paranasal Sinuses Functions of paranasal sinuses Lighten the skull Give resonance and amplification to voice Figure 5.10
- 57. The Hyoid Bone The only bone that does not articulate with another bone Serves as a moveable base for the tongue Figure 5.12
- 58. The Fetal Skull The fetal skull is large compared to the infants total body length Figure 5.13
- 59. The Fetal Skull Fontanelles – fibrous membranes connecting the cranial bones Allow the brain to grow Convert to bone within 24 months after birth Figure 5.13
- 60. The Vertebral Column Vertebrae separated by intervertebral discs The spine has a normal curvature Each vertebrae is given a name according to its location Figure 5.14
- 61. Structure of a Typical Vertebrae Figure 5.16
- 62. The Bony Thorax Forms a cage to protect major organs Figure 5.19a
- 63. The Bony Thorax Made-up of three parts Sternum Ribs Thoracic vertebrae Figure 5.19a
- 64. The Appendicular Skeleton Limbs (appendages) Pectoral girdle Pelvic girdle
- 65. The Appendicular Skeleton Figure 5.6c
- 66. The Pectoral (Shoulder) Girdle Composed of two bones Clavicle – collarbone Scapula – shoulder blade These bones allow the upper limb to have exceptionally free movement
- 67. Bones of the Shoulder Girdle Figure 5.20a, b
- 68. Bones of the Upper Limb SlideCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings The arm is formed by a single bone Humerus Figure 5.21a, b
- 69. Bones of the Upper Limb SlideCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings • The forearm has two bones • Ulna • Radius Figure 5.21c
- 70. Bones of the Upper Limb Slide 5.36Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings The hand Carpals – wrist Metacarpals – palm Phalanges – fingers Figure 5.22
- 71. Bones of the Pelvic Girdle Slide 5.37Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Hip bones Composed of three pair of fused bones Ilium Ischium Pubic bone The total weight of the upper body rests on the pelvis Protects several organs Reproductive organs Urinary bladder Part of the large intestine
- 72. The Pelvis SlideCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 5.23a
- 73. Gender Differences of the Pelvis Slide 5.39Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 5.23c
- 74. Bones of the Lower Limbs SlideCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings The thigh has one bone Femur – thigh bone Figure 5.35a, b
- 75. Bones of the Lower Limbs SlideCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings The leg has two bones Tibia Fibula Figure 5.35c
- 76. Bones of the Lower Limbs Slide 5.41Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings The foot Tarsus – ankle Metatarsals – sole Phalanges – toes Figure 5.25
- 77. Joints Slide 5.43Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Articulations of bones Functions of joints Hold bones together Allow for mobility Ways joints are classified Functionally Structurally
- 78. Functional Classification of Joints Slide 5.44Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Synarthroses – immovable joints Amphiarthroses – slightly moveable joints Diarthroses – freely moveable joints
- 79. Structural Classification of Joints Slide 5.45Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Fibrous joints Generally immovable Cartilaginous joints Immovable or slightly moveable Synovial joints Freely moveable
- 80. Fibrous Joints Slide 5.46Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Bones united by fibrous tissue – synarthrosis or largely immovable. Figure 5.27d, e
- 81. Cartilaginous Joints – mostly amphiarthrosis Slide 5.47Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Bones connected by cartilage Examples Pubic symphysis Intervertebral joints Figure 5.27b, c
- 82. Synovial Joints Articulating bones are separated by a joint cavity Synovial fluid is found in the joint cavity Figure 5.27f–h
- 83. Features of Synovial Joints- Diarthroses Articular cartilage (hyaline cartilage) covers the ends of bones Joint surfaces are enclosed by a fibrous articular capsule Have a joint cavity filled with synovial fluid Ligaments reinforce the joint
- 84. Structures Associated with the Synovial Joint Bursae – flattened fibrous sacs Lined with synovial membranes Filled with synovial fluid Not actually part of the joint Tendon sheath Elongated bursa that wraps around a tendon
- 85. The Synovial Joint Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 5.28
- 86. Types of Synovial Joints Based on Shape Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 5.29a–c
- 87. Types of Synovial Joints Based on Shape Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 5.29d–f
- 88. Inflammatory Conditions Associated with Joints Bursitis – inflammation of a bursa usually caused by a blow or friction Tendonitis – inflammation of tendon sheaths Arthritis – inflammatory or degenerative diseases of joints Over 100 different types The most widespread crippling disease in the United States
- 89. Clinical Forms of Arthritis Osteoarthritis Most common chronic arthritis Probably related to normal aging processes Rheumatoid arthritis An autoimmune disease – the immune system attacks the joints Symptoms begin with bilateral inflammation of certain joints Often leads to deformities
- 92. Clinical Forms of Arthritis Gouty Arthritis Inflammation of joints is caused by a deposition of urate crystals from the blood Can usually be controlled with diet