Microbial Disease of the Nervous System

• The Central Nervous System, os composed of what?

  Brain and Spinal Cord
• It functions as the MASTER CONTOL CENTER of the body.

  The central nervous system
• It is the largest upper part of the brain. It controls the VOLUNTARY MUSCLES, PERCEPTION, and THINKING

  Cerebrum
• It is the lower part that control may INVOLUNTARY body movements, such as swinging the arms while walking 


  Cerebellum
• This connects the brain to the spina cord. It controls breathing, heart rate, and blood pressure

  Brain Stem
• Below the lumbar region, is a bundle of nerves that extendes from the spinal cord. This bundle resembles the tail of a horse

  Cauda equina
• This surrounds the brain and spinal cord, providing support and protection from EXTERNAL SHOCK

  Meninges
• This is a tough fibrous sheath that provides a strong, yet flexible covering for the SOFT ORGANS of the CNS. It also provides a barrier against the spread of infection from the bones.

  Dura mater
• It contains numerous branching fibers giving the appearance of a SPIDER’S WEB

  Arachnoid Mater
• These are the cavities between the fibers of the arachnoid mater

  Subarachnoid Spcae
• This is a fluid that leaks from the blood into the subarachnoid space that lines the brain. This WATERY fluid circulates throughout the subarachnoid space of both brain and spinal cord, to BATHER BOTH ORGANS. This is also acts as a SHOCK ABSORBER; provides nutrients, electrolytes, and oxygen to the nervous tissues; and removes wastes.

  Cerebrospinal Fluid (CSF)
• This is a medical procedure that physicians use to remove a sample of CSF from the region of the subarachnoid space surrounding the CAUDE EQUINA


  Lumbar puncture (spinal tap)
• This is the opposite of CNS. This system is composed of nerves that TRANSFER commands from the CNS to muscles and glands throughout the body and provide information to the CNS concerning events in the body.

  Peripheral Nervous System (PNS)
• These nerves extends from the brain through holes in the cranial bones

  Cranial Nerves
• This extend from the spinal cord through the gaps between vertebrae

  Spinal Nerves
• What are the three types of nerves?

  Sensory Nerves, Motor Nerves, and mixed nerves
• This type of nerve primarily carries signals TOWARD the CNS


  Sensory nerves
• This type of nerve carries signals from the CNS to OTHER ORGANS of the body

  Motor Nerves
• This type of nerve carries signals BOTH TOWARD and AWAY from the CNS

  Mixed Nerves
• The entire nervous system is composed of two basic types of cells. What are these?

  Neurons and Neuroglia
• what does the neuroglia do?

  They provide a supportive scaffolding, insulation, and nutritive supposed and phagocytize microbres.
• It generates an electrical signal called an ACTION POTENTIAL or NERVE IMPULSE 


  Cytoplasmic Membrane of neuron
• Outside the CNS, is a collection of many neurons cell bodies, what are those?

  Ganglion
• There are two types of finger like cytoplasmic processes extend from a cell body.

  Axon and Dendrite
• These are numerous, perhaps hundreds short finger like cytoplasmic processes

  Dendrites
• Longer single ____


  Axon
• The terminal ends of axons have thousands of branches that form junctions called what?

  Synapses
• CNS is a considered an ______ environment

  Axenic environment- it has NO normal microbiota
• How do pathogens access the CNS?

  Through breaks in the bones and meninges, through medical procedures such as spinal taps, or by travel via axonal transport in peripheral neurons to the CNS
• What cause meningitis?


  it is when microbes carried in the blood or lymph may penetrate the blood-brain barrier by infecting and killing cells of the meninges
• It is the inflammation of the meninges

  Meningitis
• Which is the most common bacterial infection of the nervous system?

  Bacterial Meningitis
• It involves the inflammatory bacterial infection of the meninges, commonly the PIA MATER and ARACHNOID MATER and, more rarely, the DURA MATER

  Bacterial Meningitis
• Bacterial meningitis is characterized by what?

  An increased number of white blood cells in the CSF, sudden high fever, and intense meninges inflammation.
• In bacterial meningitis, a lumbar puncture reveals normally clear CSG to be _____ in APPEARANCE because of the large number of bacteria and the increased number of WHITE BLOOD CELLS

  Milky
• It is a small, dark purplish HEMORRHAGES of blood vessels in the skin- sometimes present while bacterial meningitis

  Petechiae
• What are the five species that cause almost 90% of cases of bacterial meningitis?

  -Neisseria meningitidis

  -Streptococcus pneumonia

  -Haemophilus influenzae

  -Listeria monocytogens

  -Streptococcus agalactiae
• It is Gram- negative cocci that regularly cause disease in humans. The cells of all strains of this are NONMOTILE and are typically arranged as DIPLOCCI (PAIRS) with their common sides flattened in a manner reminiscent of COFFEE BEANS 


  Neisseria Meningitidis
• Damage caused by N. meningitidis results from what? (this is a process in which the bacterium sheds extrusions of its outer membrane)

  Blebbing
• This bacteria was actually discovered by Louis Pasteur in pneumonia patients about 120 years ago

  Streptococcus pneumoniae