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48 Cards in this Set
- Front
- Back
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Functions of Nervous System
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Sensory - afferent
Integrative - bridge gap Responsive - effectors |
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Nervous Sys is two parts
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CNS
PNS |
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CNS
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Structure - brain and spinal cord
Function - Integration & command center of Nervous sys |
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PNS
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Structure - 43 prs of nerves Somatic, Automatic...
Function - spinal nerves, cranial nerves... |
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somatic ns
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voluntary ns
motor (efferent) ns from cns to skel, muscles, glands Sensory (afferent) ns convey impulses to cns |
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Autonomic (involuntary) ns
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Functions out of our control.
Regulates activity of smooth & cardiac muscle, as well as glands. Sympathetic and Parasympathetic |
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Sympathetic
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fight or flight
pounding heart rapid deep breathing cold sweaty skinn dilated pupils |
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Parasympathetic
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resting and digesting
systems at "normal" skin warm pupils constricted lens set at close vision |
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Hindbrain (Brain stem)
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medulla oblongata
pons cerebellum |
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Medulla oblongata
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Sensory - taste, pharynx, viscera, abdominal cavities and motor nuclei.
Motor - cardiac center, vasomotor center and respiratory center |
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pons
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conducts signals from cerebrum to cerebellum
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Cerebellum
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more subconscious
muscular coordination, judging passage of time, cognitive processes, emotion |
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Cerebrum
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More conscious
sensory perception memory thought judgment voluntary motor actions |
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diencephalon
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thalamus
hypothalamus epithalamus |
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Thalmus
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all info goes through
grey matter gateway to cerebral cortex sensory input going to the... |
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Hypothalamus
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Major control center of ans ....
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epithalamus
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pineal gland
habenula |
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spinal cord functions
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conduction
locomotion reflexes |
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branches of spinal nerves
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dorsal ramus
ventral ramus small meningeal branch |
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grey matter
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slow no myelin
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white matter
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fast
3 columns divide into tracts - dorsal, lateral and ventral |
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spinal tracts
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ascending, descending and decussation (contralateral, ipsilateral)
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Ascending tracts
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1st order neurons
2nd order neurons 3rd order neurons |
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descending tracts
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carry impulses down brain stem and cord.....
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Spinal shock
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syndrome - flacid paralysis of muscles exhibited after spinal injury
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types of paralysis
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para - both lwr t1-l1
quadri - c5 hemi - stroke |
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3 protective layers of cns
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dura mater - subdural space
arachnoid mater - sub arachnoid space pia mater |
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dura mater 2 layers thick
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Periosteal lyr
meningeal lyr |
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Purposes of CSF
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Buoyancey - density similar to brain, brain considerable size w/o being impaired by it own weight
Protection - from stiking the cranium Chemical stability - rinses waste and regulates chem envir |
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3 parts of brain
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cerebrum
cerebellum brainstem |
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cerebrum facts
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83% of brain
2 half globes separated by deep longitudinal fissure each hemisphere has folds - gyri and shallow grooves - sulci |
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cerebrum facts - 5 lobes + ...
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frontal - high mental process'
parietal - recieve & interpret signal occipital - vision temporal - hear, smell, memory insula - small role in hearing, smell & visceral sensation |
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basal nuclei
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also basal ganglia. masses of cerebral gray matter involved in motor control
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cerebral white matter contains
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projection tracts - connect higher to lower brain
commissural tracts - connect diff regions of diff hemispheres assoc tracts - connect different regions of same hemisphere |
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3 higher brain functions
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Primary cortex - rec input from sense organs
Association cortex - all other regions involved in integrative functions Special senses - vision, hearing taste, smell, equilibrium |
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3 neuron functions
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excitability - irritable, neurons are highly excitable and highly responsive to stimuli, responsive to changes around them
conductivity - nerve impulses / responses to stim, traveling signals to alert cells secretion of neurotransmitters |
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neuron structure
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cell body
dendrites axon neurofibrils, microtubules terminal axon ends synapse |
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3 functional classes of neurons
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sensory - input
interneurons - w/i cns - make decision of how to respond to stim motor - output |
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4 neuron variety
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multipolar-1 axon, 2 or more dendrites (most common)
bipolar-1 axon 1 dendrite (olfactory, retina, inner ear) unipolar - signals to spinal cord anoxonic - multiple dendrites, no axon (brain/retina) |
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synape def and 2 types
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junction between axon and next neuron, muscle or gland.
elect syn - ions diff directly fro 1 axon to the adjoining structure chem syn - communicate by neurotransmitters |
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4 Neuronal circuits
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diverging
converging reverberating linear seq a-b-c-d-a.. parallel |
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resting membrane potential
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electrolytes are unequally distributed between the ecf and icf
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RMP results from 3 factors
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diffusion of ions
selective permeability electrical attraction |
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action potential
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nerve impulse or changes Na and K diffusion...
electrical impulses will be conducted the same regardless of the source |
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depolorization
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Na gates open & membrane become permeable to Na.
Na enters axon by diffusion making i/s more +. Na gates are voltage regulated - permeability to Na at explosive rate. |
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repolorization
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K ions rush out of cell
shift of voltage back into neg #'s |
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refractory period
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absolute rp - no stim of any strength will trigger action potential.
relative rp - it is possible to trigger new action potential w unusually strong stim. |
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synaptic transmission
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nerve signal arrives at synaptic knob.
Ca enters knob and triggers release of acetylcholine and diffuses across cleft and binds to ligand regulated gates on the post synaptic neuron, causing the stim to begin in the next neuron |
