I.                    Functions of Bone

a.       Supports and gives shape to the body

b.      Protects internal organs

c.       Helps make movement possible

d.      Stores calcium

e.       Hemopoiesis (blood cell formation)

II.                 Types of Bones

a.       Long Bones – example:  humerous (upper arm)

b.      Short Bones – example:  carpals (wrist)

c.       Flat – example:  frontal (skull)

d.      Irregular – example:  vertebrae

III.               Structure of Long Bones

a.       Structural Components

                                                               i.      Diaphysis or shaft

                                                             ii.      Medullary cavity containing yellow marrow

                                                            iii.      Epiphyses or ends of bone; spongy bone contains red bone marrow

                                                           iv.      Articular cartilage – covers epiphyses as a cushion

                                                             v.      Periosteum – strong membrane covering bones except at joint surfaces

                                                           vi.      Endosteum – lines medullary cavity

IV.              Microscopic Structure of bone and cartilage

a.       Bone types

                                                               i.      Spongy

1.      Texture results from needlelike threads of bone called trabeculae surrounded by a network of open spaces

2.      Found in epiphyses of bones

3.      Space containts red bone marrow

                                                             ii.      Compact

1.      Structural unit is osteon (Haversian system) – composed of concentric lamella, lacunae containing osteocytes, and canaliculi, all covered by periosteum

b.      Cartilage

                                                               i.      Cell type is called chondrocyte

                                                             ii.      Matrix is gel-like and lacks blood vessels

V.                 Bone Formation and Growth

a.       Sequence of development early – cartilage models replaced by calcified bone matrix

b.      Osteoblasts form new bone, and osteoclasts re-absorb bone

VI.              Divisions of Skeleton

a.       Axial Skeleton

                                                               i.      Skull

                                                             ii.      Spine

                                                            iii.      Thorax

                                                           iv.      Hyoid bone

b.      Appendicular Skeleton

                                                               i.      Upper extremities, including shoulder girdle

                                                             ii.      Lower extremities, including pelvic girdle

c.       Location and description of bones (See diagram)

VII.            Differences between a Man’s and a Woman’s Skeleton

a.       Size – male skeleton is generally larger

b.      Shape of Pelvis – Male pelvis is deep and narrow, female pelvis is broad and shallow

c.       Size of Pelvic Inlet – female pelvic inlet generally wider – normally large enough for baby’s head to pass through it.

d.      Pubic Angle – angle between pubic bones of female is generally wider

VIII.         Joints (Articulations)

a.       Kinds of Joints

                                                               i.      Synarthroses (no movement) – fibrous connective tissue grows between articulating bones; for example:  sutures of the skull

                                                             ii.      Amphiarthroses (slight movement) – cartilage connects articulating bones; for example:  symphysis pubis

                                                            iii.      Diarthroses (free movement) – most joints belong to this class

1.      Structure of freely moveable joints – joint capsule and ligaments hold adjoining bones together but permit movement at the joint.

2.      Articular Cartilage – covers joint ends of bones and absorbs jolts

3.      Synovial membrane – lines joint capsule and secretes lubricating fluid

4.      Joint cavity – space between joint ends of bones

b.      Types of freely moveable joints

                                                               i.      Ball and socket (hips, shoulders)

                                                             ii.      Hinge (knees, elbows)

                                                            iii.      Pivot (axis / atlas joint at base of skull)

                                                           iv.      Saddle (phalanges)

                                                             v.      Gliding (vertebrae)

                                                           vi.      Condyloid (wrist)

IX.              Skeletal Disorders

a.       Bone Tumors and Cancer – benign or malignant neoplasms of bone, cartilage, and fibrous tissue.

b.      Metabolic Bone Disease

                                                               i.      Osteoporosis – excessive loss of bone matrix (mineral and collagen)

                                                             ii.      Osteomalacia – softening of bone from loss of mineral (but not volume) in bone matrix; called Rickets in children.

                                                            iii.      Paget’s Disease – osteitis deformans; abnormal bone remodeling in which spongy bone is replaced by disorganized, excessive bone matrix.

c.       Bone Infection

                                                               i.      Osteomyelitis – general term for bacterial (usually staphylococcal) infection of bone.

                                                             ii.      Bone infections may also be caused by viruses, fungi, and other pathogens

d.      Bone fractures

                                                               i.      Open (Compound) fractures pierce the skin and closed (simple) fractures do not.

                                                             ii.      Complete fractures involve total separation of bone fragments, and incomplete fractures involve partially separated fragments; comminuted fractures involve many fragments.

                                                            iii.      Fracture lines can be classified by their angle relative to the bone’s axis:  linear, transverse, and oblique

e.       Joint disorders

                                                               i.      Noninflammatory joint disease does not usually involve inflammation of the synovial membrane.

1.      Osteoarthritis – degenerative joint disease; degeneration of articular cartilage

2.      Traumatic injuries:  dislocation of articular cartilage is called subluxation; damage involving ligaments is called a sprain.

                                                             ii.      Inflammatory joint disease (arthritis) – inflammation of synovial membrane with systemic signs or symptoms

1.      Rheumatoid arthritis -  autoimmune inflammation of synovial membrane and other structures; juvenile form is especially severe

2.      Gouty arthritis – synovial inflammation caused by gout, a condition in which sodium urate (Uric Acid) crystals form in joints and other tissues

3.      Infectious Arthritis – arthritis resulting from infection by a pathogen, as in Lyme arthritis caused by the Lyme disease bacterium.