Lecture 11- CNS Diseases Flashcards
The nervous system
2 main parts;
*CNS= includes the brain, spinal cord which process information from PNS
*PNS= includes nerves that branch off the spinal cord + extend to all parts of the body; collecting info and sending it to the CNS
Microbial entry into the CNS;
Skull/backbone fractures
Medical procedures
Along peripheral nerves
Blood/lymph
Brain= protected against microbial invasion by cellular barriers; blood-brain barrier + blood-cerebrospinal fluid barrier
-cells within the CNS= produce an immune response against invading pathogens
Microbial diseases of the nervous system
-microbes= grow in the cerebrospinal fluid in the subarachnoid space of the CNS
-blood brain barrier prevents passage of some materials into the CNS
*meningitis= inflammation of meninges (often bacterial)
*encephalitis= inflammation of the brain (viral)
*myelitis= inflammation of the spinal cord
The meninges and cerebrospinal fluid
Meninges;
3 membranous layers that cover + protect the CNS
-deliberate blood to CNS tissue via blood vessels
-produces cerebrospinal fluid; clear fluid that cavities of the cerebral ventricles + surrounds the brain and spinal cord
Bacterial meningitis
Symptoms; fever, headache + stiff neck
-followed by nausea + vomiting
-may progress to convulsions + coma
-most dangerous in young children
Meningitis
Haemophilus influenzae meningitis; slides 12-18
Meningococcal caccination; 19-25
Listeriosis
listeria monocytogenes;
-gram-negative aerobic rod
-usually foodborne= can be transmitted to the fetus
-reproduce in phagocytes
listeria meningitis;
-occurs in babies, elderly (weak immune systems)
-passed to baby during pregnancy/whilst giving birth
Tetanus and Botulism
Tetanus; clostridium tetani
-gram +, endospore-forming, obligate anaerobes
-grows in deep wounds
*tetanospasmin = released from dead cells blocks relaxation pathways in muscles
-prevention by vaccination with tetanus toxoid + booster
Treatment= tetanus immune globulin
Botulism; clostridium botulinum
-gram +, endospore-forming, obligate anaerobe
-intoxication= from ingesting botulinum toxin
Botox= blocks release of neurotransmitter causing flaccid paralysis
Prevention = nitrites prevent endospore germination in sausages
Botulism
Treatment= supportive care + antitoxin
Infant botulism= botulinum growing in intestines
Wound botulism= growth of C.botulinum in wounds
Leprosy
-mycobacterium leprae
-grows n peripheral nerves and skin cells
Transmission requires prolonged contact with an infected person
*tuberculoid form; loss of sensation in skin areas; positive lepromin test
*lepromatous form; disfiguring nodules over body; negative lepromin test
Poliomyelitis
-poliovirus
Transmitted = ingestion
Initial symptoms= sore throat + nausea
Prevention= vaccination
Rabies virus (rhabdovirus)
Transmitted= animal bite
Virus multiplies in skeletal muscles -> brain cells -> causing encephalitis
Initial symptoms; muscle spasms of mouth, pharynx and hydrophobia
Furious rabies= animals are restless then excitable
Paralytic rabies= animals seem unaware of surroundings
Post exposure treatment= vaccine plus immunoglobulin
Cryptococcus Neoformans Meningitis
Amphotericin B
African Trypanosomiasis
Slides 41-45
