Nervous system Flashcards
What is the somatic nervous system for?
Conscious control, breathing, motor, etc
What is the autonomic nervous system for?
Regulates involuntary physiological processes such as heart rate, blood pressure, respiration, digestion and sexual arousal
What is the autonomic system divided into?
Sympathetic (fight or flight)
Parasympathetic (return to normal baseline/rest and digest)
What does the parasympathetic nervous system do?
Constricts pupil
Stimulates salivation
Slows heart rate
Constricts bronchi
Stimulates digestion
Causes bladder to contract
What does the sympathetic nervous system do?
Dilates pupil
Inhibits salivation
Increases heart rate
Dilates bronchi
Inhibits digestion
Inhibits contraction of bladder
What is the enteric nervous system?
Branch of the ANS which operates completely separately to sympathetic and parasympathetic nervous systems
Controls gut and gut functions
Communicates through neurotransmitters such as dopamine, serotonin and acetylcholine - control blood flow into the stomach and bowels
What do the nerves at C1-C3 control?
Neck muscles
What do the nerves at C4 control?
Diaphragm
What do the nerves at C5 control?
Deltoid (shoulder)
What do the nerves at C6 control?
Wrist
What do the nerves at C7 control?
Triceps
What do the nerves at C7-C8 control?
Fingers
What do the nerves at T1 control?
Hand
What do the nerves at T2-T12 control?
Intercostals (trunk)
What do the nerves at T7-L1 control?
Abdominals
What do the nerves at T11-L2 control?
Ejaculation
What do the nerves at L2 control?
Hips
What do the nerves at L3 control?
Quadriceps
What do the nerves at L4-L5 control?
Hamstrings - Knee
What do the nerves at L4-S1 control?
Foot
What do the nerves at S2 control?
Penile erection
What do the nerves at S2-S3 control?
Bowel and bladder
How are dermatomes (map and location on skin) useful?
They are a good way of recognising/diagnosing if there is any damage to the spinal cord or nerve transmission
Each spinal nerve corresponds to a specific level and sensation is mapped to that level
If a patient has a sensation only above a certain area, we know what nerves are affected
What nerves does the cervical spine hold?
All the nerves that control the respiratory system and all movement
What nerves does the Thoracic spine hold?
Control of core muscles and arms as well as lower limbs
Respiratory control above T4
What nerves does the Lumbar spine hold?
Controls hips, bladder and bowels, arms, ejaculation/vaginal contraction
What nerves does the Sacrum control?
Erection and some bladder function
What are some examples of diseases that affect the CNS?
Alzheimer’s
Parkinson’s
Epilepsy
Motor Neurone disease
What are some examples of diseases that affect the PNS?
Diabetes
Gullian-Barre
What does the frontal lobe of the brain control?
Personality/behaviour planning
Decision making
Concentration
Voluntary motor functions
Primary motor cortex (precentral gyrus)
What does the temporal lobe of the brain control?
Understanding speech
Interpretation and storage of auditory and olfactory sensations
What does the parietal lobe of the brain control?
Comprehension and language
Sensory functions (pain, heat and other sensations)
Primary somatosensory cortex (post central gyrus)
What does the occipital lobe of the brain control?
Primary visual cortex
Processing visual information
Storing visual memories
What does the cerebellum control?
Coordination
Balance
Stores memories of previously learned movement patterns
What does the brain stem control?
Breathing
Swallowing
Heart rate
Arousal and wakefulness
What does contra-lateral control?
The side of the body that will be affected by damage to the brain will be the opposite of the side of the brain where the damage is
What does Broca’s area control?
The muscles of the larynx, pharynx and mouth that enable us to speak
What does Wernicke’s area control?
Understanding of language
What does the hippocampus control?
Object recognition
Stores meaningful words or places
What is a Cerebral Vascular accident (CVA)?
A stroke
Interruption of blood supply to the brain, caused by a blocked or burst blood vessel
Cuts off the supply of oxygen and nutrients causing damage to brain tissue
What are the 2 types of CVA?
Ischaemic
Haemorrhagic
What is an Ischaemic stroke?
Obstruction or blockage within the Blood Vessels
Thrombo/embolic stroke
What are some risk factors for an ischaemic stroke?
Hypercholesterolemia
Hypertension
Atrial Fibrillation
Ischaemic heart disease/angina
Peripheral vascular disease
Diabetes
Previous stroke/TIA
Smoking
Increased alcohol intake
Poor diet/obesity
Increased age (atherosclerosis)
Oral contraceptive pill
Drug misuse
What are some risk factors for a haemorrhagic stroke?
Chronic high blood pressure
Amphetamine
Amyloid angiopathy
Arterial Venous malformation (AVM)
Inflammation of blood vessels (vasculitis)
Bleeding disorders
Anticoagulants
What is a subdural haematoma?
A type of haematoma associated with traumatic brain injury
Blood gathers between the dura matter and the brain
Usually results from tears in braiding veins which cross the subdural space - may cause an increase in intracranial pressure (ICP) which can cause compression of and damage to delicate brain tissue
Are subdural haematomas (SDHs) life threatening?
Often life threatening when acute
Chronic SDHs have a better prognosis if properly managed
What is the frequency of Ischaemic CVAs/Cerebral infarctions?
84%
What is the frequency of Intracerebral haemorrhages?
13%
What is the frequency of Subarachnoid haemorrhages?
6%
What is the risk of recurrence of a CVA within 5 years?
30-40%
What are the reasons to perform a neurological assessment?
Identify the presence of nervous system dysfunction
Detect life-threatening situations
Establish a neurological baseline for the patient
Compare data to previous assessments to determine change, trends and necessary interventions
Determine the effects of nervous system dysfunction on activities of daily living and independent function
Provide a database upon which nursing interventions will be implemented
What is the ACVPU score?
Level of consciousness
Alert
Confusion
Voice
Pain
Unresponsive
What are the benefits of the ACVPU score?
Basic and quick assessment of neurological capacity
Points to action and requires minimal training to be able to use
Able to identify deterioration
What are the limitations of the ACVPU score?
Does not have diagnostic capacity
What is the Glasgow Coma Scale?
A neurological assessment that evaluates 3 key categories of behaviour that most closely reflect activity in the higher centres of the brain
Enables MDT to determine whether the patient has cerebral dysfunction
What are the 3 categories that the GCS evaluates?
Eye opening
Verbal response
Motor response
How does the GCS work?
Within each category, each level of response is attributed a numerical value - the lower the value, the greater the neurological deterioration and resulting brain insult
What is a mild brain injury on the GCS?
13 or higher
What is a moderate brain injury on the GCS?
9-12
What is a severe brain injury on the GCS?
8 or less
What is the lowest score on the GCS?
3 - indicates that the patient is completely unresponsive
What is assessed during the eyes and pupillary response (E)?
Does the patient open their eyes spontaneously?
If not why not? Are they unable to open eyes due to trauma/swelling?
Do they open their eyes to speech? Are you speaking into their ear? Are they deaf?
If you are using a pain stimuli how are you doing this? - be sensitive, do not cause harm
Check pupillary response to bright light - do the pupils dilate/contract when exposed to bright light? Do they dilate when eyelids closed?
What are the scores for the E response of the GCS?
1 - no response (neurological dysfunction in RAS (brain stem))
2 - response to pain (reduced function of RAS and cortex)
3 - response to speech (RAS and cortex function, motor cortex, CN3 all intact)
4 - spontaneously (RAS, thalamus and cortex function intact, CN3 intact)
How is the voice response assessed?
Approach patient
Are they alert/orientated?
Are they confused? If so how confused? Are they using inappropriate words? Is it full sentences or is it a mumbled response?
If uttering confused words are they actually able to form words or are they incomprehensible sounds?
If unresponsive, have you raised your voice? Are they deaf? Are you shouting into the wrong ear?
