Musculoskeletal Pathophysiology

Musculoskeletal Anatomy and Physiology, Musculoskeletal Disorders

1. Musculoskeletal Pathophysiology

2. Composition of the Musculoskeletal System 1) Bone 2) Muscle 3) Joints 4) Ligaments 5) Tendons

3. Bones and Muscles Joints

4. Bone Functions 1) Body movement 2) Body position 3) Stabilize joints 4) Maintain body temperature

5. Bone Shape Short Long Flat Irregular

6. Bone Tissue Intracellular Matrix – strong, rigid structure of fibers and calcium phosphate Compact Bone – outer bone covering Spongy Bone – interior bone

7. Bone Cells Osteocytes – mature bone cells Osteoblasts – producing cells that make collagen and matrix proteins Osteoclasts – resorption cells that secrete collagenase

8. Functions of Muscles 1) Produce body movement 2) Stabilize body position 3) Regulate organ volume 4) Move substances within the body 5) Generate heat

9. Smooth Muscle Major Location – walls of hollow viscera, blood vessels Major Function – movement of viscera, peristalsis, vasoconstriction Cellular Characteristics – no striations, single nucleus, and lacks transverse tubules Mode of Control - involuntary Characteristics of Contractions – contracts and relaxes slowly; self-exciting; rhythmic

10. Cardiac Muscle Major Location – heart walls Major Function – pumping action of the heart Cellular Characteristics – has striations, single nucleus, and well-developed transverse tubules; intercalated discs separate adjacent cells Mode of Control - involuntary Characteristics of Contraction – network of cells contracts as a unit; self-exciting; rhythmic

11. Skeletal Muscle Major Location – muscles Major Function – movement of bones at joints, maintenance of posture Cellular Characteristics – has striations, many nuclei, and well-developed transverse tubules Mode of Control – voluntary Characteristics of Contraction – contracts and relaxes rapidly

12. Joints Functions Act as levers for complex movement Maintain body posture Types 1) Synarthroses – immovable joints 2) Amphiarthroses – slightly moveable joints 3) Diarthroses – freely moving joints

13. Ligaments Connect bone to bone

14. Tendons Connect muscles to bone

15. Fractures Present with bleeding, local inflammation, and necrosis of tissue at the end of the broken bone. Types of Fractures Complete – break ends across entire bone Incomplete – some of fracture components are still partially joined Comminuted – crushed, small, crumbled bone fragments near the fracture Pott’s Fracture – fracture of the lower tibia LeFort Fracture – fracture of the face and/or base of skull

16. Osteoporosis Decrease in bone mass and bone density Loss of bone matrix and bone mineralization Predisposing Factors : 50+ y/o, sedentary, hormonal, low BMI, diet, and Asian/European Ancestry Treatment : dietary supplements like calcium and vitamin D, weight-bearing activities, and PT

17. Rickets and Osteomalacia Deficit of vitamin D and phosphates. Weak bones in pediatrics Soft bones in adults

18. Paget’s Disease Excessive bone destruction with replacement by fibrous tissue and abnormal bone

19. Tumors Bone is a common area of secondary tumors. Primary tumors are usually malignant. Types 1) Osteosarcoma – cancerous tumor in bone 2) Chondrosarcoma – cartilage cells in adults 3) Ewing’s Sarcoma – shaft of long bone in adolescents

20. Muscular Dystrophy Autosomal recessive disorder causing degeneration of skeletal muscle Signs/Symptoms in boys : dystrophin deficit, and replacement of skeletal muscle by fat and fibrous connective tissues Diagnostic Tests : genetic abnormalities, elevated creatine kinase levels, EMG, muscle biopsy, blood test Treatment : no curative treatment, only supportive treatment - moderate exercise, PT/OT, massage, assistive device, or ventilator

21. Osteoarthritis Degenerative wear and tear of bone Cause : increased weight lifting or articular cartilage damage. Signs/Symptoms : bone spurs, inflammation, rough and worn surface, lack of range of motion, pain, and falls Treatment : assistive devices, NSAIDS, glucosamine-chondroitin supplements, or joint replacement

22. Rheumatoid Arthritis Autoimmune, chronic, systemic, and inflammatory disease. Cause : unknown Signs/Symptoms : synovitis, red and swollen joints, pannus formation, cartilage erosion, fibrosis, muscle atrophy, muscle spasms, muscle contractions Systemic Signs/Symptoms : fatigue, anorexia, mild fever Treatment : rest, limit activity, heat/cold therapy, NSAIDS, glucocorticoids, analgesics, surgery, and drugs

23. Gout Cause : deposits of uric acid in the joint Signs/Symptoms : inflammation, redness, swelling, pain Diagnosis : examination of synovial fluid, blood tests Treatment : reduce uric acid levels by drugs and dietary changes

24. Ankylosing Spondylitis Cause : joint fixation, inflammation of spinal joint or costovertebral joints, inflammation of intervertebral spaces of axial skeleton, fibrosis, calcification of joints Signs/Symptoms : low blood pressure, pain when supine, rigid spine Systemic Signs/Symptoms : fatigue, fever, weight loss, iritis Treatment : relieve pain, restore mobility, anti-inflammatory drugs, analgesics, daily exercise, PT/OT