CHAPTER 20 Flashcards
what occurs most frequently? viral, bacterial, or fungal infections
viral
What are the two parts of the nervous system?
central nervous system and peripheral nervous system
What is the CNS composed of?
brain and spinal cord
What are the main parts of the brain?
cerebrum controls voluntary muscles, perception, and thinking; cerebellum controls many involuntary body movements; brain stem controls breathing, heart rate, bp
How far does spinal cord extend?
brain stem to lumbar region
Where do cranial nerves extend?
from brain through holes in cranial bones
Where do spinal nerves extend?
spinal cord through vertebral gaps
What are the 3 types of nerves?
sensory, motor, mixed
What are sensory nerves?
carry signals toward the CNS
What are motor nerves?
carries signals away from CNS
What are mixed nerves?
carry signals toward and away from CNS
What are the two basic cell types in the nervous system?
neuroglia and neurons
What are neuroglia?
provide support, insulation, and nutrients; phagocytize microbes
What are neurons?
carry nerve impulses, nucleus lies in cell body, ganglion is collection of many neurons’ cell bodies, dendrites and axons extend from cell body
What is synapse?
junction at the terminal ends of axons; mediates signal transfer to postsynaptic cell; synaptic cleft stops transmission of electrical signals
What are neurotransmitters?
chemical signals between cells; may be either stimulatory or inhibitory
What type of environment is the CNS?
axenic- it has no normal microbiota
What are ways pathogens can access the CNS?
break in bones and meninges, medical procedures, travel in peripheral neurons to the CNS, infect and kill cells of the meninges causing meningitis, inflammation can alter the permeability of the blood-brain barrier
viruses more readily cross the______
blood-brain barrier
polio only exists endemically in what 2 countries
pakistan and nigeria
t or f
protozoan infections of the nervous system are common
false; rare
mycoses are spread from the lungs to the CNS via the____
blood
a prion is a ____ _____
infection protein
a prion disease leaves the brains of the victims ______
full of holes
Sties are caused by what bacteria
S. aureus
define sties
infections of sebaceous glands near eye
define Ophthalmia neonatorum – N. gonorrhoeae
inflammation of the conjunctiva and cornea of a
newborn
define conjunctivitis
inflammation of conjuctiva
define keratitis
inflammation of the cornea
