The skeletal system consists of bones, joints, and cartilage that provide structure, protection, movement, and support. There are two main divisions - the axial skeleton which includes the skull, vertebral column, and rib cage, and the appendicular skeleton which includes the limbs and girdles. Bones can be classified by their shape as long, short, flat, or irregular. The skeletal system allows movement through articulations between bones at joints like the ball and socket hip joint. Common diseases include arthritis, fractures, osteoporosis, and various cancers that affect the bones and bone marrow.

1. The Skeletal System: Structure, Function, and Diseases of the bones and joints

2. The Skeletal System Parts of the skeletal system Bones (skeleton) Joints Cartilages Ligaments (bone to bone)(tendon=bone to muscle) Divided into two divisions Axial skeleton Appendicular skeleton – limbs and girdle

3. Functions of Bones Support of the body Protection of soft organs Movement due to attached skeletal muscles Storage of minerals and fats Blood cell formation

4. 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

5. Microscopic Anatomy of Bone

6. Bones are classified by their shape : long short flat irregular

7. Classification of Bones on the Basis of Shape

8. Classification of Bones Long bones Typically longer than wide Have a shaft with heads at both ends Contain mostly compact bone Examples: Femur, humerus

9. Gross Anatomy of a Long Bone Diaphysis Shaft Composed of compact bone Epiphysis Ends of the bone Composed mostly of spongy bone

10. 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

12. Classification of Bones Short bones Generally cube-shape Contain mostly spongy bone Examples: Carpals, tarsals

13. 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

14. Classification of Bones Irregular bones Irregular shape Do not fit into other bone classification categories Example: Vertebrae and hip

15. 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

16. 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

17. 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 Parts of ribs Joints

18. 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

20. 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

21. Common Types of Fractures

22. Stages in the Healing of a Bone Fracture

23. Axial skeleton supports and protects organs of head, neck and trunk Axial skeleton: skull (cranium and facial bones) hyoid bone (anchors tongue and muscles associated with swallowing) vertebral column (vertebrae and disks) bony thorax (ribs and sternum) Appendicular skeleton includes bones of limbs and bones that anchor them to the axial skeleton Appendicular skeleton: pectoral girdle (clavicles and scapulae) upper limbs (arms) pelvic girdle (sacrum, coccyx) lower limbs (legs) Articulation- where joints meet, connect, and are formed.

24. 22 bones in skull 6 in middle ears 1 hyoid bone 26 in vertebral column 25 in thoracic cage 4 in pectoral girdle 60 in upper limbs 60 in lower limbs 2 in pelvic girdle 206 bones in all

26. The Axial Skeleton Forms the longitudinal part of the body Divided into three parts Skull Vertebral column Bony thorax

27. The Axial Skeleton

28. The skull 8 sutured bones in cranium Facial bones: 13 sutured bones, 1 mandible Cranium encases brain attachments for muscles sinuses

30. Bones of the Skull

31. Allows for growth

32. Human Skull, Superior View

33. Human Skull, Inferior View Figure 5.9

34. Paranasal Sinuses Hollow portions of bones surrounding the nasal cavity

35. The Hyoid Bone The only bone that does not articulate with another bone Serves as a moveable base for the tongue

36. The Vertebral Column Vertebrae separated by intervertebral discs The spine has a normal curvature Each vertebrae is given a name according to its location

37. Vertebral column 7 cervial vertebrae 12 thoracic 5 lumbar 1 sacrum (5 fused 1 coccyx (4 fused) Vertebrae vary in size and morphology

39. Structure of a Typical Vertebrae

40. Thoracic cage ribs thoracic vertebrae sternum costal cartilages True ribs are directly attached to the sternum (first seven pairs) Three false ribs are joined to the 7 th rib Two pairs of floating ribs

42. Joints Fibrous - Fibrous joints connect bones without allowing any movement. The bones of your skull and pelvis are held together by fibrous joints. Cartilaginous - Cartilaginous joints are joints in which the bones are attached by cartilage. These joints allow for only a little movement, such as in the spine or ribs. Synovial - Synovial joints allow for much more movement than cartilaginous joints. Cavities between bones in synovial joints are filled with synovial fluid. This fluid helps lubricate and protect the bones. Bursa sacks contain the synovial fluid. within fixed limits

43. A joint, or articulation, is the place where two bones come together. There are three types of joints classified by the amount of movement they allow: Immovable slightly movable freely movable

44. Types of Joints Hinge- A hinge joint allows extension and retraction of an appendage. (Elbow, Knee)

45. Ball and Socket- A ball and socket joint allows for radial movement in almost any direction. They are found in the hips and shoulders. (Hip, Shoulder)

46. Gliding- In a gliding or plane joint bones slide past each other. Mid-carpal and mid-tarsal joints are gliding joints. (Hands, Feet)

47. Saddle- This type of joint occurs when the touching surfaces of two bones have both concave and convex regions with the shapes of the two bones complementing one other and allowing a wide range of movement. (Thumb)

48. 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

49. The Synovial Joint

50. Types of Synovial Joints Based on Shape

51. Types of Synovial Joints Based on Shape

52. Diseases and Conditions of the Skeletal System

53. Arthritis

57. Bursitis Inflammation of the Bursa sac can become inflamed from injury or infection localized pain or swelling

60. Tendonitis inflammation of the tendon. movement becomes painful. most common cause of tendonitis is overuse.

62. Carpal Tunnel Syndrome swelling or change in position of the tissue within the carpal tunnel squeezes and irritates the median nerve. causes tingling and numbness of the thumb, index, and the middle fingers

65. Osteoporosis means "porous bones." bones have lost minerals ( especially calcium) making them weak, brittle, and susceptible to fractures most common places where fractures occur are the back, hips, and wrists.

69. Scoliosis abnormal curvature of the spine. one or more abnormal More girls than boys have severe scoliosis.

74. Kyphosis spine may develop a hump. can occur as a result of developmental problems or degenerative diseases

77. Lordosis A curvature of the vertebrae in the lower back area, giving a "swayback" appearance.

80. Rickets softening and weakening of bones in children usually because of an extreme and prolonged vitamin D deficiency.

84. Gout results from an overload of uric acid in the body. leads to the formation of urate crystals that deposit in the joints. crystals in the joints causes recurring attacks of joint inflammation (arthritis). Chronic gout may cause joint destruction, decreased kidney function, and kidney stones.

88. Acromegaly occurs when the body produces too much of the hormones that control growth. tissues grow larger than normal. excessive growth can cause serious disease and even premature death.

93. Spina Bifida birth defect that involves the incomplete development of the spinal cord or its coverings. spina bifida literally means "split" or "open" spine. The condition usually is detected before a baby is born and treated right away.

97. Talipes Equinovarus- “Clubfoot” deformity of the whole foot that is present at birth. the child is born with the foot pointing down and twisted inwards at the ankle.

101. Sarcoma Osteosarcoma most common type of bone cancer. most commonly found in children and adolescents

107. Myeloma cancer in which abnormal cells collect in the bone marrow and form tumors

110. Leukemia cancer of the blood cells starts in the bone marrow where blood cells are the bone marrow starts to make a lot of abnormal white blood cells, called leukemia cells. leukemia cells don't do the work of normal WBC’s and they don't stop growing when they should.

113. Bone Marrow Biopsy