MIDTERM WEEK 6 NERVOUS SYSTEM EXAM 2 STUDY GUIDE
Week 6 Nervous System
1. Differentiate parasympathetic, and sympathetic nervous system.
o Autonomic Nervous System: Made up of the sympathetic and parasympathetic nervous
systems. o Parasympathetic Nervous System: conserves energy and the body’s resources. o
Sympathetic Nervous System: responds to stress by preparing the body to defend itself
Catecholamines released - epinephrine
mobilizing energy stores, and decreases the release of insulin;
redistributes blood flow – increases to muscles (flight) and lungs, decreases to GI and
integumentary
2. Primary Brain Injury: can be classified as focal or diffuse.
Focal: are specific, grossly observable brain lesions that occur in a precise location (Epidural hemorrhage;
subdural hemorrhage.
Diffuse injuries, also called multifocal injuries, include brain injury due to hypoxia, meningitis,
encephalitis, and damage to blood vessels.
Swelling, commonly seen after Traumatic Brain Injury (TBI), can lead to dangerous increases in intracranial
pressure. – Remember the brain is within a limited space, thus increased pressure can cause collateral
dysfunction: Diabetes Insipidus (ADH not secreted thus polyuria)
3. Define autonomic hyperreflexia.
Individuals most likely to be affected have lesions at the T5-T6 level or above. Autonomic
hyperreflexia is characterized by paroxysmal hypertension (up to 300 mm Hg systolic), a
pounding headache, blurred vision, sweating above the level of the lesion with flushing of the
skin, nasal congestion, nausea, piloerection caused by pilomotor spasm, and bradycardia (30 to
40 beats/minute).
4. Delirium, dementia
Comparison of Delirium and Dementia
FEATURE DELIRIUM Dementia
Age Usually older Usually older
FEATURE DELIRIUM Dementia
, Usually insidious; acute in
Onset Acute—common during hospitalization some cases of
strokes/trauma
Urinary tract infection, thyroid disorders, Associatedhypoxia, May have no other
hypoglycemia, toxicity, fluidconditions electrolyte imbalance, renal conditions
insufficiency,
trauma, multiple medications Brain trauma
Course Fluctuating; remits with treatment Chronic slow decline
Duration Hours to weeks Months to years
Intact early; often impaired
Attention Impaired
late
Sleep-
Usually normal or
Disrupted wake
fragmented
cycle
Alertness Impaired Normal
Orientatio
Intact early; impaired late
Impaired n
Behavior Agitated, withdrawn/depressed Intact early
Speech Incoherent, rapid/slowed Word-finding problems
Thoughts Disorganized, delusions Impoverished
PerceptionHallucinations/illusions Usually intact early
FEATURE DELIRIUM Dementia
, s
7. Alzheimer Disease
Alzheimer disease (dementia of Alzheimer type [DAT], senile disease complex) is the leading cause of dementia and
one of the most common causes of severe cognitive dysfunction in older adults. The greatest risk factors are age and
family history. Other proposed risk factors include diabetes, midlife hypertension, hyperlipidemia, midlife obesity,
smoking, depression, cognitive inactivity or low educational attainment, female gender, estrogen deficit at the time
of menopause, physical inactivity, head trauma, elevated serum homocysteine and cholesterol levels, oxidative
stress, and neuroinflammation. Proposed protective factors include lifelong activity, the presence of apoE2 and
antioxidant substances, estrogen replacement at the time of menopause, low-calorie diet, and use of nonsteroidal
anti-inflammatory agents. Statins are being investigated for their role in preventing AD.
Pathophysiology
The exact cause of AD is unknown and there is no clear understanding of this complex disease process. Early-onset
familial Alzheimer disease (FAD) is autosomal dominant and has been linked to three gene defects: amyloid precursor
protein (APP) gene on chromosome 21, presenilin 1 (PSEN1) on chromosome 14, and PSEN2 on chromosome.
The specific diagnosis of AD is made by postmortem examination. The clinical history, cognitive testing, course of the
illness, laboratory tests, and brain imaging are used for diagnostic evaluation. The course of the disorder is highly
variable, usually developing over 5 years or more. Genetic susceptibility tests for PSEN1, PSEN2, and APP are used to
screen for early-onset AD.
8. Stroke: The incidence of stroke is about two times higher in blacks than whites. Stroke tends to run in families. Of
all strokes, most are ischemic (thrombotic or embolic). No identifiable cause can be established by conventional
diagnostic tests in many ischemic strokes and they are classified as “undetermined” or “cryptogenic.”
The mildest outcome of a cerebrovascular accident (CVA) is so minimal as to be almost unnoticed. The most severe
outcomes are hemiplegia, coma, and death. Strokes are classified according to pathophysiology: ischemic (thrombotic
or embolic) is the most common, global hypoperfusion (as in shock), or intracerebral hemorrhage. Hypertension is the
single greatest risk factor for stroke. Risk factors for stroke include the following:
• Arterial hypertension
• Insulin resistance and diabetes mellitus
• High total cholesterol or low high-density lipoprotein (HDL) cholesterol level, elevated lipoprotein-A level
• Hyperhomocysteinemia
• Congestive heart disease and peripheral vascular disease
• Asymptomatic carotid stenosis
• Polycythemia and thrombocythemia
• Atrial fibrillation
• Postmenopausal hormone therapy
• High sodium intake, >2300 mg; low potassium intake, <4700 mg
• Smoking
• Physical inactivity