consciousness Flashcards
what can make you biologically conscious
having action potentials traveling around the brain which is not visible when you are brain dead as there are no signals for electrodes to pick up
what are the different sensory pathways
- proprioceptors
- chemical sensors
- vestibular sense
- hearing
- vision
- touch and conscious proprioception
how does the vision pathway work
- light enters into the eye and onto the retina
- it goes past a layer of cells until it hits the rods and cones
- the rods and cones change shape in response to light in relationship to the resting membrane potential of the cells
- these changes then cause a release in neurotransmitters
- the signal stops at the lateral genic nuclei which are in the thalamus
how does hearing occur through the sensory pathway
- vibration enter and vibrate the outer ear
- these vibrations vibrate the tympanic membrane
- the malleus, incus and stapes move
- the cochlea is then vibrated
- fluid inside the cochlea vibrates
- the stereocilia then move causing an influx of K and Ca
- the cell is then depolarised stimulating the release of neurotransmitter
- auditory signal is then sent to the brain/ thalamus
how do chemical sensors affect the sensory pathway
- chemicals binding cause a change in resting potential of the cell
- this then changes the secretion of the chemicals on the afferent nerve
what is the function of proprioceptors in the sensory pathway
it tells you where you your body is
how does the ascending reticular activation system affect consioucness
- a lesion to the mid pons can cause unconsciousness as this is part of the ARAS
- changes in neurotransmitter of the reticular formation change the neurotransmitters GABA, Orexins and ACh that are released
- part of sleep control as well
where does sensation, organization and perception occur
in the thalamus
how does sensation, organisation and perception occur in the thalamus
- the reticular excitatory area sends excitatory action potentials to the thalamus
- the thalamus excites almost all areas of the cortex
- thalamus and reticular activating system keeps the cortex awake and informed about the environment
what does the primary somatosensory cortex do
it is where sensation is processed
what happens if there is a lesion in the somatosensory association cortex
pain will be felt for example and you know where it is but you can’t say much about it
- is the same for other sensations
what occurs in the primary cortical areas
- simple perception
- single modes of perception
what happens in the secondary cortical areas
- more complex perception
- single modes of perception
what happens in the polymodal posterior association area
all sensory ends up in the posterior association area where all sensations are combined to form you internal view of the world
what are the parts of the polymodal association area
- posterior association area
- anterior association area
