Flashcards in MSK Random Facts Deck (86)
Popliteal fluid collection commonly related to chronic joint disease
Most commonly involved ligament in an ankle sprain
What innervates the teres minor?
Injury classically seen in cyclists
Guyon canal injury to ulnar nerve
What supplies sensation to the lateral forearm?
Musculocutaneous nerve (C5-7)
What can you get with a superficial laceration of the Palm?
Injury to the recurrent branch of the median nerve, loss of thenar muscle group, no loss of sensation
Lower trunk damage (C8-T1), loss of the intrinsic muscles of the hand, total claw hand-lumbricals normally flex MCP joints and extend DIP and PIP joints
Thoracic outlet syndrome
Compression of lower trunk and subclavian vessels
What do the interossei do
Dorsal interossei-abduct the fingers, Palmer interossei- adduct the fingers
What can cause an inferior gluteal nerve injury?
Posterior hip dislocation, nerve is L5-S1
What's in the anterior compartment?
Anterior tibial artery and deep peroneal nerve
What occurs during the power stroke?
Myosin releases bound ADP and PO4 causing displacement of the myosin and actin filament
What is ATP used for in the muscle contraction?
Myosin releasing actin
What is a type 1 muse fiber?
Slow twitch, red fiber, increased mitochondria and myoglobin concentration, used for sustained contraction
What is a type 2 muscle fiber?
Fast twitch fiber, white fiber, more anaerobic glycolysis, weight training results in hypertrophic of fast-twitch muscle fibers
External rotation and extension causing pain->medial meniscal tear; internal rotation and extension->lateral meniscal tear
How is contraction stimulated in smooth muscle?
AP opens L-type voltage gated Ca channel-> increased Ca in the cell binds to calmodulin-> Ca-calmodulin complex enhances myosin-light chain kinase, which phosphorylates myosin and leads to contraction
What do osteoblasts come from?
Differentiate from mesenchymal stem cells in the periosteum
What do osteoclasts come from and how do they work?
Differentiate from monocytes, macrophages. Multinucleated cells that dissolve bone by secreting acid and collagenases
Estrogens effects on bone
Estrogen inhibits apoptosis in bone-forming osteoblasts and induces apoptosis in bone-resorbing osteoclasts
Genetics of achondroplasia
Autosomal dominant (but >85% are sporadic), constitutive activation of fibroblast growth factor receptor (FGFR3) inhibits chondrocyte proliferation
Osteoporosis histo and labs
Trabecular (spongy) bone loses mass and interconnections despite NORMAL mineralization and lab values
What is denosumab?
Monoclonal antibody against RANK-L
MOA of osteopetrosis
Mutations (eg, carbonic anhydrase II) impair ability of osteoclast to generate acidic environment necessary for bone resorption. Leads to thickened, dense bones that are prone to fracture. Pancytopenia and extramedullary hematopoeisis
What's wrong in rickets/osteomalacia?
Defective mineralization/calcification of osteoid
Lab values in rickets
Low vit D, low Ca, high PTH, low phos
Lab values in Pagets
Normal Ca, phos, and PTH. Elevated ALP.
Histo of pagets
Mosaic pattern of woven and lamellar bone
What are rheumatoid nodules