Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
41 Cards in this Set
- Front
- Back
Composition of bone
|
Organic matrix: osteoblasts, osteoclasts, type I collagen, glycoproteins. Inorganic matrix: calcium hydroxyapatite, magnesium, potassium, chloride, sodium
|
|
Osteoblasts
|
Production of unmineralized bone. High amounts of alkaline phosphatase and PTH receptors to modulate osteoclasts
|
|
Osteoclasts
|
Bone resorption
|
|
Achodroplasia
|
Inherited dwarfism. Mutation on fibroblast growth factor receptor 3 inhibits cartilage synthesis at the epiphysial plates with decreased endochondral bone formation and premature ossification of growth plates. Short and thick extremities, large head and trunk.
|
|
Osteogenesis imperfecta
|
Abnormal synthesis of type I collagen. Recurrent fractures and deformities, thin blue sclera, deafness, thin skin and easy bruising
|
|
Causes of osteoporosis
|
Primary causes: estrogen deficiency with high IL-1 activity (postmenopausal, Turner's), genetic factors, lack of exercise, old age, nutritional. Secondary causes: Immobilization, Cushing's, thyrotoxicosis, malnutrition, corticosteroids.
|
|
Clinical features of osteoporosis
|
Bone is normal but in decreased amounts. Bone pain, compression fractures (vertebrae), femoral neck fracture, distal radius fracture.
|
|
Radiographic, lab and microscopic features of osteoporosis
|
Radiolucency of bone (osteopenia). Normal serum calcium, phosphorus and alkaline phosphatase. Thinned cortical and trabecular bone
|
|
Treatment of osteoporosis
|
Estrogen replacement therapy, weight bearing exercise, calcium, vitamin D, biphosphonates, calcitonin
|
|
Causes of osteomalacia and rickets
|
Decreased mineralization of newly formed bone due to abnormal metabolism of vitamin D. Dietary deficiency, intestinal malabsorption, lack of sunlight, renal and liver failure
|
|
Clinical features of rickets
|
Occurs in children. Craniotabes and frontal bossing (skull deformities), deformity of chest wall, pigeon breast, bowing of the legs. Low serum calcium with high alkaline phosphatase and PTH
|
|
Clinical features of osteomalacia
|
In adults, bone pain, fractures of vertebrae, hips and wrist. Low serum calcium, high alkaline phosphatase and PTH
|
|
MC pathogen in osteomyelitis
|
Staph
|
|
Osteomyelitis in sickle cell disease
|
Salmonella
|
|
Osteomyelitis in drug abusers and diabetics
|
Pseudomonas
|
|
Clinical features of osteomyelitis
|
Fever, leukocytosis, localized pain, erythema and swelling
|
|
Clinical features of osteoarthritis
|
Wear and tear joint chondrocyte injury with loss of articular collagen in weight-bearing joints. Stiffness, decreased range of motion, crepitus, pain that worsens with motion, old age. X-ray shows narrowing of joint space and osteophytes.
|
|
Clinical features of rheumathoid arthritis
|
Systemic, chronic inflamatory disease with anti-IgG autoantibodies (rheumathoid factor). Affects hands, wrists and knee, symetrical involvement, morning stiffness that improves with activity. Systemic manifestations: fever, fatigue, lymphadenopathy, rheumathoid subcutaneous skin nodules, Sjogren syndrome (15%)
|
|
Microscopic, x-ray and lab findings in rheumathoid arthritis
|
X-ray: juxta-articular osteoporosis and bone erosions. Micro: Synovitis, pannus (proliferation of synovium and granulation tissue over joint cartilage), radial deviation of wrist, ulnar deviation of fingers. Lab: high ESR, hypergammaglobulinemia, rheumathoid factor (anti-IgG).
|
|
Ankylosing spondylitis associations
|
young males, HLA-B27
|
|
Reiter syndrome
|
Conjunctivitis, urethritis, arthritis of ankles and knees, HLA-B27, follows gonococus infection
|
|
Causes of gout
|
Primary (90%) idiopathic. Secondary: Leukemia, renal disease, Lesch-Nyhan, Von Gierke
|
|
Clinical features of gout
|
Exquisite pain in big toe. Negatively birefringent, needle-shaped uric acid crystals and neutrophils in aspiration. Complications: joint destruction, uric acid renal calculi, renal failure. Rx.: NSAIDs, colchicine, probenecid allopurinol
|
|
Infectious arthritis clinical features
|
Gonococci MC. Tender, swollen and erythematous joints, monoarticular arthritis. Cloudy sinovial fluid that clots, neutrophils and positive gram stain in aspiration
|
|
Clinical features of myasthenia gravis
|
Autoantibodies against Ach receptors at neurmuscular junction. Ptosis, diplopia, weakness. Associated with thymic hyperplasia and thymomas. Rx.: anticholinesterase agents, thymectomy
|
|
Eaton-Lambert syndrome
|
Paraneoplastic syndrome of SCC of lung. Autoantibodies against the presynaptic Ca+ channels at neuromuscular junction.
|
|
Duchenne muscular dystrophy
|
Absence of dystrophin muscle structural protein. Onset of symptoms by age 5, progressive muscular weakness, heart failure, respiratory insuficiency and infections. High serum CK.
|
|
Guillain-Barre syndrome
|
Preceded by viral illness. Ascending paralysis, loss of deep tendon reflexes. Inflamation and demyelination of peripheral nerves and spinal nerve roots result in muscular weakness
|
|
Vitiligo
|
Irregular, completely depigmented patches devoid of melanocytes.
|
|
Melasma
|
Irregular blortchy patches of hyperpigmentation on the face
|
|
Freckles
|
Light brown macules on face, shoulders and chest. Increased melanin deposition in the basal layer of the epidermis
|
|
Nevocellular nevus (mole)
|
Benign tumor of melanocytes with sharp well-circumscribed borders
|
|
Malignant melanoma
|
Asymetric, irregular borders, variegated color, large diameter, enlarging, macule, papule or nodule. Risk factors: chronic sun exposure, fair skin, dysplastic nevus syndrome
|
|
Acanthosis nigricans
|
Thickened, hyperpigmented skin in axillae and groin. Associated with malignancy and gastric adenocarcinoma
|
|
Psoriasis
|
Well demarcated erythematous plaque with a silvery scale. Epidermal hyperplasia (acanthosis), patchy keratinization with parakeratosis. Rx.: topical steroids and radiation
|
|
Pemphigus
|
Autoantibodies against desmosome component desmoglein 3 results in loss of intracellular adhesion (acantholysis) and blister formation. Easily ruptured, flaccid blisters. Immunofluorescence shows net-like pattern of IgG stainning
|
|
Bullous pemphigoid
|
Autoantibodies against hemidesmosome component bullous pemphigoid antigens 1 and 2 result in separation of epidermis from dermis and blister formation. Tense bullae that do not rupture easily. Eosinophils are seen
|
|
Dermatitis herpetiformis
|
IgA autoantibodies against gliadin that deposit in the tips of the dermal papillae with subepidermal clister formation. Microabsecesses with neutrophils are seen
|
|
Squamous cell carcinoma of the skin risk factors
|
Chronic sun exposure, fair complexion, chronic skin ulcers, xeroderma pigmentosa, actinic keratosis
|
|
Squamous cell carcinoma of the skin clinical features
|
Tan nodular mass which ulcerates on sun exposed areas. Micro: nests of atypical keratinocytes invade the dermis, formation of keratin pearls, desmosomes between tumor cells
|
|
Basal cell carcinoma of the skin clinical features
|
Chronic sun exposure, fair complexion, xeroderma pigmontosum. Pearly papules and nodules with heaped up translucent borders, telangiectasia, ulcerations. Palisading growth pattern
|