Integrated Basic Science Review MusculoSkeletal SystemB Dr Paul

Integrated Basic Science Review Musculo-Skeletal System-B Dr. Paul S. Anderson Copyright – Medical Board Review Services

Posterior Pelvic Ligaments

MUSCULOSKELETAL – SKELETAL - 1 • Osteomyelitis: – Pyogenic dt staph, hematogenous seeding – Brodie’s abscess=walled off area of bacteria – Sinus tracts develop, squamous carcinoma common at sinus tracts • Tubercular osteomyelitis: – Blood borne TB, thoracic & lumbar spine, destructive. • Osteoporosis: – Primary: menopausal, reduction of bone mass/matrix & demineralization – Secondary: due to disease (advanced hyperthyroid, PTH Dz. states…) • Osteomalacia: – just demineralization of bone • Osteochondroma: – Most common benign bone tumor. • Exostoses with cartilagenous covering. • Chondrosarcoma is a risk with multiple lesions • Paget’s/Osteitis Deformans: – – Paramyxovirus Lytic mixed with sclerotic areas, especially skull, bowing of femur/tibia, osteoarthritis, pathologic fracture common

MUSCULOSKELETAL – SKELETAL - 2 • Osteoma (Benign): – Normal bone exostosis on skull – If multiple then Gardener’s syndrome=intestinal polyps & sarcomas • Osteoid Osteoma (Benign): – Tumor of osteoblasts in vertebrae & long bones, young adults • Osteosarcoma: – Primary bone cancer, adolescent males, familial • Secondary to Paget’s in elderly, knee, hip, humerus, jaw. – Destructive, mixed lytic & blastic, lifts periosteum (painful) • Hematogenous spread to lungs, bone, brain. – Second most common primary malignant bone CA. • Chondrosarcoma: – Malignant tumor of cartilage • Pelvis of middle-aged men, shoulders, ribs, painful enlarging mass – Most common primary malignant bone tumor, • Can metastasize, • Ewing’s Sarcoma: – More common in the young. • Extremely malignant, – Viscous liquid like pus in marrow, sheets of round cells, • Metastatic

MUSCULOSKELETAL – JOINT 1 • Osteoarthritis: – Progressive erosion of articular cartilage • Subchondral cysts, osteophytes, hips, knees, lumbar, cervical • Herberden’s nodes (osteophytes at DIP), • Bouchard’s nodes (at PIP) • Rheumatoid Arthritis: – Collagen-vascular dz, females 25 -50 – RF positive – Nodules at the PIP joints • Pannus (inflammed synovial tissue), rice bodies (fibrin), infiltrates, vasculitis, Felty’s syndrome=RA, splenomegaly, nuetropenia, deformity, • Baker’s cyst=outpouching of synovium behind knee, prolonged am stiffness, a – Arthritis in 3 or more joints, symmetric.

MUSCULOSKELETAL – JOINT-2 • SERONEGATIVE ARTHRITIDES: – Psoriatic Arthritis: RF-, HLA B 27+ • In 10% of patients with Psoriasis. • DIP degeneration. – Enteropathogenic Arthritis: RF-, HLA B 27+ • Patients with UC / Crohn’s (more in UC), • Also after Salmonella / Shigella or Yersinia infection. • Symmetric arthritis of – Knees, Ankles, Wrists, SI Joints. – Reactive arthritis: RF-, HLA B 27+ • Also known as – Arthritis urethritica, venereal arthritis and polyarteritis enterica. Reiter’s Syndrome. • Male dominant, post Chlamydia infection • Urethritis / Conjunctivitis / Asymmetric lower extremity arthritis: – (Knees. Ankles, Fingers, Toes)

MUSCULOSKELETAL – JOINT-3 • Chrondromalacia: – Softness of the articular (Hyaline) cartilage, usually involving the patella • Apparently caused by unbalancing elements of the quadriceps with patellar misalignment during movement. • Osteochondroses: e. g. Osgood-Schlatter’s Dz • Ganglion: – Cystic tumor developing on a tendon or aponeurosis. – Arises from cystic or myxoid degeneration of connective tissue.

MUSCULOSKELETAL – JOINT 4 • Infectious Arthritis: – GC, staph, strep, TB, Lyme • Acute painful swollen single joint, fever • Common post trauma. • Gouty Arthritis: – Hyperuricemia, uric acid in & around joints • 1 st MTP, tophi in olecranon, prepatellar, calcaneal tendon, pinna, – Genetic, heavy alcohol use. • (DDX: pseudo-gout: Sn/Sx without increased uric acid). • Ankylosing Spondylitis: – Marie-Stumpell dz, adolescent males – Bony ankylosis of SI & vertebral processes with severe spinal immobility

Triangles of the Ventral Neck

Posterior Left Shoulder

Skeletal Muscle a. Location (1) Skeletal Attachments (2) Limbs, Trunk b. Somatic Innervation c. Contraction (1) Powerful, Voluntary (2) Variable fatigue between White and Red Fibers

MUSCLE TYPES • RED MUSCLE DIVIDES INTO: – “SO” SLOW OXIDATIVE – “FOG” FAST OXIDATIVE GLYCOLYTIC • WHITE MUSCLE FIBERS : FG ONLY

ISOTONIC AND ISOMETRIC CONTRACTION

MUSCLE TONE CONTROL

MUSCLE TONE CONTROL

MUSCLE CONTRACTION : THE BIG PICTURE SKELETAL – SMOOTH - CARDIAC • SKELETAL AND CARDIAC – AT REST: Tp/Tm BLOCK ACTIN / MYOSIN BINDING – AP Ca INFLUX Ca BINDS Tp / Tm ACTIN / MYOSIN BIND ATP-> ADP MUSCLE CONTRACTION …. RELAXATION = Ca BACK TO SARCOPLASM VIA T-TUBULES • SMOOTH MUSCLE – DEPOLARIZATION VIA Ca INFLUX FROM • MITOCHONDRIA • EXTRACELLULAR SOURCES • INTRACELLULAR VESSICLES – CALMODULIN & LIGHT CHAIN KINASE PHOSPHORYLATE ACTIN / MYOSIN CONTRACTION

ELECTROMECHANICAL COUPLING

STRENGTH