nervous system Flashcards
function of the nervous system
responsible for body’s ability to both interact with environment and to regulate/control the body and internal organs, muscles, glands
alterations in cognitive systems, arousal and awareness
any state not fully conscious.
Consciousness is arousal (state of awakeness) and awareness (content of thought.
Arousal-mediated y reticular activating system (RAS), regulating aspects of attention and information process, and maintains consciousness
Cognitive cerebral functions require a functioning RAS.
Awareness encompasses all cognitive functions and is mediated by attentional systems, memory systems, language systems, and executive systems. Selective attention (orienting) is ability to select specific information to process from all available competing environmental and internal stimuli
Memory deficits, image processing difficulties, poor vigilance, poor detection of threats, poor short term memory
alterations in cognitive systems, data processing deficits
problems associated with recognizing and processing sensory information
Agnosia- defect of pattern recognition, failure to recognize form and nature of objects. Can be tactile, visual, auditory, generally only one sense is affected. Sometimes objects cant be named by touching it, but able to name it by looking at it
Aphasias - impairment of comprehension or production of language, impaired written or verbal communication. Also called dysphasia. Can be expressive, receptive, mixed (repeats words spoken to them), mute,
Acute confusional state - transient disorders of awareness, either sudden or gradual onset, delirium
alterations in cognitive systems, seizures
manifestation of disease, not a specific disease entity. Sudden, transient disruption in brain electrical function, caused by abnormal excessive discharges of cortical neurons.
Any disorder altering neuronal environment can cause seizures. Metabolic congenital, genetic predisposition, perinatal, postnatall, myoclonic syndromes, brain tumor, vascular disease, drug/ETOH abuse, hypoglycemia, fatigue, lack of sleep, stress, fever, water intoxication, constipation, antipsychotics, respiratory alkalosis - hyperventilation, blinking lights, poorly adjusted television screen, loud noises, certain music, odors, being startled, increased risk for women before or during menses
alterations in cerebral dynamics, ICP
ICP - normal is 5-15 mmHg. Increased ICP happens with increased intercranial content. Blood, edema, tumors, excess CSF. Must reduce volume of other cranial contents. Stages 1-4, with progressing levels of LOC loss.
1 - vasoconstriction and external compression of venous system occur to compensate, so ICP may not change much as body compensates.
2 - ICP continues to increased, exceeding ability to compensate. Compromises neuronal oxygenation, arterial vasoconstriction occurs to elevate systemic BP to overcome ICP. Can include confusion, restlessness, drowsiness, slight pupillary and breathing changes
3 - ICP approaches arterial pressure, brain tissues experience hypoxia and hypercapnia, condition rapidly deteriorates. Includes decreased arousal, central neurogenic hyperventilation, widened pulse pressure, bradycardia, small and sluggish pupils
4 - brain tissue shifts (herniates) from greater pressure to compartment of lesser pressure. Blood supply is compromised, causing further ischemia and hypoxia. Small hemorrhages may develop, hydrocephalus may develop,
alteration in cognitive systems, motor function, muscle tone
movements are complex patterns of activity controlled by cerebral cortex, pyramidal system, extrapyramidal system, and muscle motor units. Dysfunction in any area can cause motor dysfunction. Normal muscle tone involves slight resistance to passive movement. resistance is smooth, constant, even.
Hypo or hypertonia
Flaccidity
Spasticity
Paratonia-resistance to passive movement
Dystonia-involuntary twisting or abnormal posture or repetitive movements
Rigidity
Plastic or lead pipe-increased muscular tone independent the degree of force in passive movement
Myotonia-impaired ability to relax after contraction
alterations in motor function, muscle movement
Dopamine has role in several movement disorders, too much or too little
Hyperkinesia, includes tremors
disorders of the nervous system and neuromuscular junction
