what r the protecting structures
Arrangement of Blood supply
what r the cranial bones
what r the facial bone
layers of the brain
what is CSF,where is it produced at what rate
CSF is the fluid that flows through and protects the 4 ventricles of the brain, the subarachnoid spaces and the spinal cord.
Produced by choroid plexis in ventricles 21mls/hr
circle of willis - main blood supply to the brain
the arteries compose the circle of Willis are the 2 anterior cerebral arteries joined to each other by the anterior communicating cerebral artery and to the posterior cerebral arteries by the posterior communicating arteries.
what is neurological assessment for
Determine whether the patient has a neurological problem
Establish what impact the condition has on the patient’s independence and daily life
Detect life threatening situations
what is the goal of neurological assessment
To standardise clinical observations, always conduct a set of neurological observations with the oncoming nurse to minimise subjectivity
Monitor progress, a neuro patient often deteriorates slowly and an accurate neuro assessment can identify a deterioration very early
Provide a guide to estimate a patient’s prognosis
what is consciousness
It is an active process
Wakefulness or alertness must be present
Potential for self-awareness
Perceived sensation of internal and external stimuli
Memory can be used, recovered and displayed
Decision making capacity
- Consciousness is more than being awake. It is a complex and multifaceted condition that is present in health.
dbescrie consciousness as a continuum? what is its component
The reality is that consciousness can be located along a continuum between two extremes
Consciousness has 2 distinct components
what is arousal
The arousal component of wakefulness is dependent on the reticular activating system.
This system is found in the upper brainstem and diencephalon ascending the brainstem, through the thalamic region and to the cerebral cortex, with the thalamus acting as a ‘gate’ between both areas
what is awareness
Awareness relates to the capacity of the brain to select and direct
Sensation is the awareness that something is happening and perception is the appropriate processing of this information
what part of brain response for conciousness?
Prefrontal lobe primary centre for consciousness
Rest of activity at the subconscious level
Involves sensory input as well as motor output
Frontal lobes: Control and awareness (cognition)
Parietal, temporal and occipital lobes: Awareness,
Association areas: Making sense of stimuli
what is conciousness depend on?
Is dependent on oxygen and glucose supply
Auto regulation of blood flow: Effective in a wide range of blood pressures as well as the maintenance of an appropriate environment.
what is cerebrl perfusion pressure
Mean Arterial Blood Pressure and Intracranial pressure
MAP- ICP = CPP
CPP less than 40mmHg leads to severe compromise of cerebral tissue
what os unconsciousness
A physiological and psychological state in which the patient is not responsive to sensory stimuli and lacks awareness of self and the environment
what cause impairment of consciousness? and what does it interfere
Injury, lesions or pressure occurring anywhere within the RAS can impair consciousness.
Interference with the electrical activity of the brain, brain metabolism or the neurotransmitters required for impulse transmission
what is the effect of altered consciousness?
Reduced or lost protective reflexes
Potential for harm if heightened consciousness
what is the mechanism of the cause of unconsciousness
The cells of the Reticular Activating system are sensitive to alterations in biochemistry and haemodynamic status therefore the causes of unconsciousness are varied and extend beyond structural cerebral lesions
what is the causes of unsciousness
1. infective: meningitis, encephalitis
2. neuplasia: gliomas (primary), metastatic cancer
3. trauma: cerebral oedema
4. haemorrhage: extradural, subdural, subarachnoid,intracerebral
5. vascular: TIA (transient ischaemic attack), CVA
6. hydrocephalus: increase ICP
7. metabolic: hypoxic, hypercapnia, hypoglycemia, uraemia.
- other causes: shock, drug overdose, anaesthetics, alcohol
shock cut to the causes of unconsciousness
how does alcohol cause unconsciousness
how does epilepsy cause unconsciousness
how does insulin cause unconsciousness
how does overdose cause unconsciousness
how does ureamia cause unconsciousness
how does temperature cause unconsciousness
how does infection cause unconsciousness
how does psychogenic cause unconsciousness
how does septicaemia cause unconsciouness