HTHS 1120 Module 3 MS

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