1. The Skeletal System

2. The Skeletal System Newborn Baby= 350 bones Fusion of bones
Mature Adult= 206 bones

3. Purposes of the bones of the Skeletal System:
Provide a framework for the body
Protect vital organs (brain, spinal cord)
Serve as levers, when muscles are attached, to help us lift and move
Store calcium, which may be reabsorbed into the blood if there is not enough calcium in the diet
Produce blood cells in the red bone marrow

4. Bones
Five most common categories:
Long
Short
Flat
Irregular
Sesamoid

5. Long bones Form legs and arms (humerus, femur) Parts of long bones:
Shaft (diaphysis): longest portion
Compact bone: solid, outer layer
Epiphysis: end of the bone that is shaped to connect to other bones (using ligaments and muscles)
Spongy bone: layer inside the compact bone that covers the space in which marrow is stored

7. Short bones Small, cube-shaped bones of the wrists, ankles and toes
Outer layer of compact bone
Inner layer of cellous bone-bone with a latticework structure

8. Flat bones Large, flat surfaces Cover organs
Provide a surface for large areas of muscle
Shoulder blades, pelvis, skull

9. Irregular bones Specialized bones with specific shapes
Ears, vertebrae, face

11. Sesamoid bones Formed in a tendon near joints Patella (kneecap)
Also found in hands and feet

13. Extensions and depressions
Serve as sites for attaching muscles and tendons
Ex: greater trochanter-bony extension near upper end of femur

15. Bone marrow Soft connective tissue Production of blood cells
Red Bone Marrow: infant bones and flat bones of adults; where red blood cells (RBC’s) start to develop
Yellow Bone Marrow: in most other adult bones; made of connective tissue filled with fat

17. Bones of the Head
Sutures: points where skull or cranial bones join

20. Bones of the Spinal Column
Five segments of vertebrae
Each separated by a cartilaginous disc
Space between vertebral body
and back= spinal cord

21. Cervical: 7
Thoracic: 12
Lumbar: 5
Sacrum: 5 at birth, fuse in adulthood
Coccyx: 4 fused bones

22. Bones of the Chest Clavicle Scapula Sternum Xyphoid Process Ribs:
True Ribs (7)
False Ribs (3)
Floating Ribs (2)

24. Bones of the Pelvis
Pubic Symphysis
Pelvic Girdle
Ilium
Ischium
Pubis

26. Bones of the Extremeties
Arm:
Humerus
Radius
Ulna
Carpals
Metacarpals
Phalanges

28. Bones of the Extremeties
Leg:
Femur
Tibia
Fibula
Tarsals
Calcaneus
Metatarsals
Phalanges

30. Joints: Points where bones connect
Bones connect to other bones using ligaments
Ligaments: bands of fibrous tissue
Movement of joint depends on the body’s need

31. Diarthroses:
joints that move freely

32. Amphiarthroses:
Cartilaginous Joints that move slightly

33. Synarthroses:
Joints that do not move; Join bones firmly

34. Synovial Joints: (another name for diarthroses)
Joints covered with a membrane that secretes a fluid lubricant to help the joint move easily

35. Fractures Breaks or cracks in bones Types:
Closed: break with no open wound
Simple (hairline): fracture, does not move any part of the bone out of place
Open (compound fracture): break with an open wound

36. Fractures, cot’d Types: Greenstick (incomplete): incomplete bone break
Comminuted: break in which the bone is fragmented or shattered
Colles’: break of the lower end of the radius
Complicated: fracture with extensive soft tissue injury

37. Fractures, cot’d Types:
Impacted: fragment from one part of a fracture is driven into the tissue of another part
Compression: break in one or more vertebrae caused by a compressing or squeezing between the vertebrae
Spiral: occurs when a bone is twisted apart

39. Diseases of the Skeletal System
Osteoporosis: softening of the bones due to lack of calcium
Occurs most often in post-menopausal women
Loss of bone density and easily broken bones

40. Diseases of the Skeletal System
Osteomyelitis: bacteria in the bone tissue
Severe pain at the end of the bone
Bone damage

41. Diseases of the Skeletal System
Arthritis: inflammation of the joints
Pain, stiffness, aching
Limited range of motion
Range of motion: measurement of the degree to which a joint is capable of moving
Osteo- and rheumatoid arthritis

42. Diseases of the Skeletal System
Sprain: injury or trauma to the joints that tears ligaments
Pain, swelling, tenderness, inability to move the area
Usually heal within two weeks

43. Diseases of the Skeletal System
Herniated Disc: one or more of the spinal discs balloon out from inside the bony parts of the vertebrae
Can cause unbearable pain if pressing on a nerve

44. Posture/Spinal Conditions
Kyphosis: humpback, rounding forward of the thoracic vertebrae
Lordosis: swayback; abnormal inward curvature of the lumbar vertebrae
Scoliosis: side-to-side curvature of the spine