Term
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Definition
verbal response, motor response and eye opening are graded.. the higher score the better prognosis
90% less than or equal to 8 are in coma
Greater than or equal to 9 not in coma
8 is the critical score
Less than or equal to 8 at 6 hours - 50% die
9-11 = moderate severity
Greater than or equal to 12 = minor injury |
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Term
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Definition
| there is a point when compensatory mechanisms begin to fail and pressure rises rapidly |
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Term
| elevated ICP, what is major concern? |
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Definition
| compression of blood vessels and lack of oxygen being delivered to brain |
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Term
| Intracranial Perfusion Pressure |
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Definition
| [mean arterial pressure -ICP] needs to be adequate 40 mmHg, more important than ICP |
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Term
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Definition
| when BP is elevated, bradychardia, pulse pressure widens; oxygen receptor in medulla are reflexively connected to BP regulation and this forces BP to rise when brain is hypoxic; at the same time heart rate will decrease because baroreceptors will register high BP and tell heart to slow down, widened pulse pressure |
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Term
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Definition
| difference between diastolic and systolic pressure |
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Term
| cerebral perfusion pressure |
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Definition
mean arterial pressure - ICP
greater than 40 mmHg; < 40 mmHg can lead to ischemia |
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Term
| cytotoxic edema --> vasogenic edema --> cytotoxic edema |
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Definition
| cells are expanding in brain and this causes increased intracranial pressure --> leads to vasogenic edema --> positive feedback loop |
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Term
| ICP elevation can be detected by... |
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Definition
| fundoscopic exam, lumbar puncture (monometer), pressure transducers |
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Term
| receptor embryological development |
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Definition
can be from nervous tissue
can be from epithelial tissue |
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Term
| Sherrington's classification |
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Definition
proprioceptor
exteroceptors -- surface stimulation
interoceptor -- internal environment (pH, O2)
telreceptors -- distance stimulation |
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Term
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Definition
visceral -- organs
deep -- proprioception
special sensory --
cutaneous --skin |
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Term
| what determines an adequate stimulus? |
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Definition
embryological origin
receptor specialization
evolutionary refinement |
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Term
what is the most sensitive receptor?
second most sensitive? |
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Definition
auditory receptors
visual receptors
low sensory threshhold |
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Term
| what senses are not so sensitive? |
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Definition
| pressure receptors, high sensory threshold |
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Term
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Definition
| the range of wavelengths of light that can elicit a change in vision receptors without destroying it |
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Term
| convergence vs divergence |
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Definition
convergence -->when multiple cells converge in one cell
divergence -->when a single cells send information to many cells |
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Term
| properties of stimulus; qualitative, quantitative, temporal and spatial |
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Definition
amplitude
temporal patterns
spatial patterns
complexity |
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Term
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Definition
| multiple sensory receptors in an area that carries the same information |
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Term
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Definition
| the size of area which corresponds to the stimulation of a single afferent fiber |
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Term
| how do receptive fields for second order neurons compare to first order neurons |
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Definition
| larger because of convergence |
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Term
| how do receptive fields for second order neurons compare to first order neurons? |
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Definition
| larger because of convergence |
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Term
| how is a receptive field for cells in the cochlea measured? |
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Definition
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Term
| how is the receptive field for lateral geniculate measured? |
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Definition
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Term
| single cells in the temporal lobe that can recognize a single face |
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Definition
| represents convergence of many neurons on a single neuron |
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Term
| receptive fields vary in size and density |
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Definition
| it is difficult to perceive small stimulus (tick on thigh versus hand) in some areas due to large receptive fields and lack of overlap |
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Term
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Definition
| brain localizes based on which pathway stimulus is imported on; if pathways change, due to cell destruction, for instance, place coding can be lost or rearranged; inherent in organization of fibers; e.g. rearrangement of cells in thalamus can change ability to localize; e.g. the sound of particular music can elicit visual perception |
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Term
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Definition
| rate of firing itself is interpreted by the brain as a particular stimulus |
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Term
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Definition
| phasic receptors; just a few initial firings; pacinian and meissner's |
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Term
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Definition
| tonic receptors; continuous firing; merkel's discs and ruffini's are slow adapting |
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Term
| how does habituation occur? |
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Definition
| the cortex decides that repeated stimulus is unnecessary |
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Term
| feature extraction often occurs on the same or different pathways? |
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Definition
| different qualities are sent on different pathways... is often determined by ecological niche |
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Term
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Definition
| physical properties of stimulus are not encoded linearly, but are logarithmic. There is a maximum response at which stimulus can increase, but response will stop increasing |
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Term
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Definition
| sensitive to stimulus features that are important for survival |
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Term
| receptive field of a joint receptor is measured in what unit? |
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Definition
| degrees... firing rate changes as angle of joint changes.. adequate stimulus is at 80 degrees for some joint receptors and higher for others (this allows place coding, different angles stimulate receptors of different thresholds) |
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Term
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Definition
| some info is blocked from being encoded at all and is often determined by ecological niche; ignoring what is not significant |
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Term
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Definition
deep touch, discriminative touch (hapsis), crude touch, vibration, itch
nocioception, temperature, kinesthesia |
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Term
| are itch and pain of the same functional modality? |
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Definition
| no... they are not sent on the same pathways. GRPR (gastrin releasing peptide receptor) itch receptor expressed in lamina 1 2nd order cell bodies |
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Term
| what two types of afferent fibers do muscle spindles have? |
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Definition
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