Applied Nervous System Flashcards
Sympathetic nervous system
- triggers response of fight or flight
- neurotransmitter adrenaline is released
- adrenaline causes an increase in heart rate, vasoconstriction, increase in blood pressure, stimulation of glycogenolysis, peristalsis and gastric absorption cease, respiratory rate increases, bronchodilation and pupillary dilation
- it is an instant response (stress response)
- if the body is still under perceived threat the hypothalamus will release CRH which travels to the pituitary gland triggering ACTH. Cortisol is then released by the adrenal glands
Parasympathetic nervous system
- controls smooth muscle and cardiac muscle, it also controls rest and digest
- it controls glands that control hormone release to counteract fight or flight
- it stimulates the release of acetylcholine which inhibits cortisol response thus returning the body to normal
- SLUDD»_space;> saliva, lacrimation, urination, digestion, defecation»_space;> this is what the parasympathetic nervous system works on
Enteric nervous system
- this is a branch of the autonomic nervous system (ANS) which operates completely separately to the sympathetic and parasympathetic nervous system
- controls the gut and its functions
- communicates through neurotransmitters such as dopamine, serotonin and acetylcholine»_space;> these control blood flow into the stomach and bowels
Application to nursing practice
- many diseases or conditions can cause injury or disruption to how the nervous system works
- there are diseases such as Alzheimer’s, Parkinson’s, epilepsy or motor neurone disease that affect the central nervous system
- there are diseases such as diabetes and Guillian-Barre that affect peripheral nervous system
- this disruption of the nervous systems function is caused by traumatic injury or disease
Supporting patients with neurological injury
- patients may present in any stage of neurological injury
- neurological injuries/ conditions may occur at any stage of life
- nurses will need to be aware of the conditions affecting their caseload
What is a CVA (stroke)?
- interruption of blood supply to the brain, caused by a blockage or burst blood vessel cutting off the supply, causing damage to the brain
- there are two types of CVA: ischaemic and Haemorrhagic
Ischaemic strokes
- caused by an obstruction or blockage
- this is the most common type of stroke
- it is also known as a thrombo/embolic stroke
Risk factors
»> hypercholesterolemia
»> hypertension
»> atrial fibrillation
»> ischaemic heart disease/angina
»> peripheral vascular disease
»> diabetes
»> previous stroke
»> smoking
»> increased alcohol intake
»> poor diet/obesity
»> increased age
»> oral contraceptive pill
»> drug misuse
Haemorrhagic stroke
- this is caused by a burst blood vessel
Risk factors
»> chronic hypertension
»> amphetamine use
»> amyloid angiopathy
»> arteriole venous malformation
»> inflammation of blood vessels
»> bleeding disorders
»> use of anticoagulants
Subdural haematoma
- this also known as subdural haemorrhage is a type of haematoma, usually associated with traumatic brain injury»_space;> in this blood gathers between the dura mater and the brain
- usually resulting from tears in bridging veins which cross the subdural space
- subdural haemorrhages may cause an increase in intracranial pressure, which can cause compression of and damage to the delicate brain tissue
- subdural haematomas are often life threatening when acute
- chronic subdural haemoatomas have a better prognosis if properly managed
Why perform a neurological assessment?
1) identify the presence of nervous system dysfunction
2) detect life threatening situations
3) establish a neurological baseline for a patient
4) compare data to previous assessments and determine the change in neurological ability and necessary interventions
5) determine effects of nervous system dysfunction on activities of daily living and independent functions
6) provide database upon which nursing interventions will be implemented
ACVPU score
Alert»_space;> Confusion»_space;> Voice»_space;> Pain»_space;> Unresponsive
- basic assessment of neurological capacity
- requires minimal training
- able to identify deterioration
- doesn’t have diagnostic capacity
Glasgow coma scale
- evaluates three key categories of behaviour that closely reflect activity in the higher centres of the brain: eye opening, verbal response and motor response
- these categories enable the MDT to determine whether the patient has cerebral dysfunction
- within each category each level of response is attributed to a numerical value»_space;> the lower the value the greater the neurological deterioration
- 13+»_space;> mild brain injury
- 9-12»_space;> moderate brain injury
- 8>»_space;> severe brain injury
Voice
Alert and orientated?
Full sentences or mumbled?
Able to form words?
Incomprehensible?
If unresponsive, raise voice?
Are they deaf? Right ear?
Motor
Obeys pain - neurologically intact
Localising pain - sensory and motor cortex intact
Flexion to pain - reduced sensory and motor processing
Abnormal flexion - blocked motor pathway between cortex ad brain stem
Extension to pain - blocked motor pathway in brainstem
None - gross neurological dysfunction
Central stimulus
Assess eye opening and motor response
Patient doesn’t obey commands
Trapezius squeeze - spinal accessory nerve
Grasp approximately 3cm of muscle and squeeze for <15 seconds