3 Basic functions of the nervous system
sensory, integrative, motor
2 sub divisions of the nervous system
CNS & PNS
What are neuroglia?
Cells that support (structurally & metabolically) neurons
What is MS?
It is characterized by an autoimmune attack that leads to oligodendrocyte injury. Damage to oligodendrocytes prevents the formation of myelin which leads to problems with conduction. This is a progressive disorder that gets worse with time.
List common symptoms of MS
Impaired motor skills, fatigue, numbness and tingling of extremities
Division of nervous system affected by MS
CNS
Visual field test
tests peripheral vision
visual acuity test
standard eye examination to determine the smallest letters a person can read on a chart, or E chart, at a distance of 14-20 feet
CT scan
a series of x-ray photographs taken from different angles and combined by computer into a composite representation of a slice through the body
MRI scan
uses magnetic fields and radio waves to produce computer-generated images that distinguish among different types of soft tissue
Lumbar Puncture
test for elevated proteins in CSF
Evoked Potential
measures how long it takes a sensory stimulus to reach the brain
3 common tests to diagnose MS
MRI, Lumbar Puncture, Evoked Potential
beta interferons
suppress the immune system thus reducing attacks on myelin sheaths
Why is MS difficult to diagnose?
symptoms come and go, plaques may not form for years
steroid treatment for MS
reduce inflammation, are nonspecific, have many side effects
sensory nerves
Nerves that carry information from the sense receptors to the spinal cord and brain, afferent neurons
integration
Processing of sensory information that comes to the CNS is called
motor nerves
Nerves that carry information from the central nervous system to the muscles of the body, efferent neurons
somatic neurons
Provide motor innervation to muscle and skin
autonomic neurons
control smooth muscle, cardiac muscle, many glands, and some adipose tissue
neuroglia of PNS
Schwann cells and satellite cells
neuroglia of CNS
astrocytes, oligodendrocytes, microglia, ependymal cells
Schwann cells
PNS, responsible for the formation of myelin
satellite cells
PNS, regulate exchanges of materials between neuronal cell bodies and interstitial fluid
astrocytes
CNS maintain proper chemical environment around neurons
Oligodendrocytes
CNS wrap axons in a myelin sheath
microglia
CNS Act as phagocytes, eating damaged cells and bacteria, act as the brains immune system
ependymal cells
CNS, line cavities of the brain and spinal cord, produce and circulate cerebrospinal fluid
brain
largest part of the nervous system housed within the cranium
action potential
conduction of electrical potential by neurons
dendrites
receiving part of a neuron
What is the visual field
total area seen by an eye when fixed on a central point
What conditions affect the visual field of the eye?
CNS tumor, diabetes, hyperthyroidism, hypertension, MS
functions affected by MS
vision, speech, walking, writing, memory
What happens to the nerve after an assault on the myelin sheath
some of the myelin may be repaired but some may disappear, scarring may occur material deposited in to the scars form plaques
what is the most common pattern of MS attacks
Relapsing-Remitting (RR-MS) which is a series of attacks followed by a partial disappearance of symptoms
what is the difference between primary progressive MS and relapsing remitting MS
PP-MS there is a gradual decline in abilities with only short periods of slight relief. In RR-MS there are long asymptomatic periods with brief periods of relapse.
how does an MRI scan differ from a CT scan
A MRI scan uses magnetism, radio waves and a computer to produce images of a body structure, a CT uses a series of x-rays.
what are the advantages of an MRI over a CT scan
An MRI scan produces much greater detail than a CT scan
what causes the characteristic plaques seen in MS
the plaques are caused by areas of demyelination in the nerves, scar tissues are formed, depositing materials
why are plaques not always seen in patients with MS
it may take years for the demyelination and scarring process to occur, the body also repairs some of the myelin following an attack
Components of the central nervous system
brain and spinal cord
Components of the peripheral nervous system
Nerves and peripheral nervous tissue
function of neurons
conduct action potentials
Parts of a neuron
cell body, axon, dendrites
Function of a myelin sheath
increases speed of an action potential
A confirmatory blood test is now available to diagnose Multiple Sclerosis.
false
Ophthalmologist
doctor that performs visual exam to assess problems with vision
Neurologist
Doctor specializing in the the neurological system that diagnoses and treats patients with MS
Home Health Nurse
provides skilled nursing for patients in their home
Medical Laboratory Scientist
assesses proteins levels in the cerebral spinal fluid
Radiology
interprets the MRI
Radiology Technician
Performs imaging studies including CT and MRI scans