C2(redirected from Command and control)
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C1, C2, . . .
1 symbols for cervical nerves.
2 symbols for cervical vertebrae.
The second cervical vertebra, a skeletal structure with a robust odontoid process that forms the pivot on which the head turns.
A designation used in UK for FNAC (fine needle aspiration cytology) samples that are adequate and contain benign epithelial cells with no features of atypia or malignancy. C2 aspirates range from poorly to moderately cellular and consist of regular ductal epithelial cells arranged in small or large flat sheets. As a rule, C2s have smooth nuclear membrane, fine chromatin, epithelial groups admixed with fragments of fatty or fibrofatty tissue, no pleomorphism and bipolar bare nuclei in the background. Fibroadenomas are the prototypic C2 lesions; other C2 pathologies include those with a cystic component (e.g., duct ectasia and fibrocystic changes), which may have histiocytes and aprocrine cells. C2s have clean backgrounds, except in inflammatory conditions. The typical C2 lesion has benign epithelial clusters and some bipolar nuclei, monolayers of benign epithelium, large number of bare nuclei and stromal fragments.
complement deficiencyA state in which any of the complement proteins is subnormal
Complement deficiencies–associated disorders
C1r SLE, renal disease, repeated infections
C2 SLE, vasculitis, membranoproliferative glomerulonephritis, dermatomyositis
C3 Repeated infections
C5 SLE, gonococcal disease
C6 Relapsing meningococcal meningitis, gonococcal infection
C7 Raynaud's disease, chronic renal disease, gonococcal infection
C8 SLE, gonococcal infection