meningitis. human brain and meningococcal bacteria.

acute agent anatomy arachnoid bacteria bacterial bacterium biology brain care causative central cerebrospinal concussion cross disease dura emergency falx fluid head health healthcare human illustration infection inflammation injury layers mater matter medical medicine meninges meningitidis meningitis meningococcal meningococci meningococcus mental microorganism mumps neisseria nerves nervous neurology organ pia pneumococci science section skull space subarachnoid subdural system virus