Neuronal Physiology Flashcards
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| 2883676946 | Synapse | Where one axon communicates with another | 0 | |
| 2883681064 | Neurons in CNS | -Most connect to other neurons -Dense configuration -Produce thoughts, movements, perceptions | 1 | |
| 2883685018 | Neurons in PNS | Most connect to muscles | 2 | |
| 2883711589 | 3 types of neurons | -multipolar -unipolar -bipolar | 3 | |
| 2883713646 | Parts of neuron: dendrites | -shorter projections; extensive branches -receive natural stimuli -conduct stimuli toward cell body | 4 | |
| 2883722779 | Parts of neurons: Axons | -longer single projections -conduct impulses away from the cell body -synapse with other neurons, glands, or muscles | 5 | |
| 2883750244 | Electrical signaling | depends on chemical makeup of intracellular and extracellular fluids -contains sodium, potassium, calcium, chloride | 6 | |
| 2883754322 | Neuronal membrane | permeable to small molecules that compose water, but impermeable to large protein ions inside the cell | 7 | |
| 2883761333 | Extracellular fluid of neurons in CSF | contains more fluid than intracellular fluid | 8 | |
| 2883764788 | osmotic force | fluids move from region of higher concentration to region of lower concentration | 9 | |
| 2883773754 | Concentration gradient | -required to maintain appropriate ion ratio across the membrane -maintained by channels and pumps in cell membrane | 10 | |
| 2883783075 | Concentration gradient channels | -selective to one ion (sodium, potassium, or chloride -gated channels open under certain conditions (chemical or electrical) -ligand sensitive channel proteins open/close channel in response to chemicals or neurotransmitters | 11 | |
| 2883792930 | Non gated channels | stay open | 12 | |
| 2883795369 | Pumps | - water filled proteins open on only one side at a time | 13 | |
| 2883796905 | Sodium-potassium pump | provides energy to cell via electrical gradient powered by the positively and negatively charged ions | 14 | |
| 2883803049 | Electrical forces: Intracellular fluid | Overall negative charge -high concentration of K, low concentration of Na and chloride -large, negatively charged ions | 15 | |
| 2883814082 | Electrical forces: extracellular fluid | -overall positive charge -no negatively charged proteins -sodium and chloride concentration is high; potassium is low | 16 | |
| 2883818723 | Electrical potentials | -created by ionic differences across cell membrane -allow for conduction of electrical current | 17 | |
| 2883821882 | Resting state | No communication between cells | 18 | |
| 2883850714 | Cellular potential | -relative amount of voltage in an electrical field -neuron has 2 electrical fields-one inside and one outside the cell | 19 | |
| 2883854735 | Resting potential | -ionic differences across cell membrane are approximately -70mV (intracellular fluid is more negative than extracellular fluid) -cell is not responding to outside influences-steady state -cell is not firing neural impulses | 20 | |
| 2883863759 | Neural messaging: deoplarization | inside of the cell becomes less negative relative to the outside of the cell (-55mV) | 21 | |
| 2883866417 | Action potential | -created when cell membrane is depolarized -begins at the axon hillock and extends down the entire axon -brief, electrical current sent from one nerve cell to another -send along axon for long distances without change in velocity or waveform (all or nothing) | 22 | |
| 2883881315 | Absolute refractory period | -short time following action potential when cell membrane is unable to respond to another stimulus -appx .8 ms -prevents stimulus from traveling back up the axon | 23 | |
| 2883887412 | Relatie refractory period | short time following absolute refractory period | 24 | |
| 2883904588 | Graded potentials (local potentials) | -usually generated by sensory input -causes change in coeducation along membrane of sensory -can be initiated at any point along cell membrane where excitatory or inhibitory synapse has taken place -not all or nothing, can change in strength | 25 | |
| 2883914700 | Hyperpolarization | -inside of cell becomes more negative relative to outside of cell -due to chloride ions influx -a greater stimulus is then required to generate an action potential | 26 | |
| 2883926599 | Myelin | -white fatty sheath around large axons of CNS, large peripheral nerves, and cranial nerves -produced by oligs in the CNS and shwann cells in the PNS -neural conduction along myleinated fibers is 50x faster than unmyleinated fibers | 27 | |
| 2883934503 | Nodes of Ranvier | -indentations in myelin that allows neural impulses to travel more rapidly -saltatory conduction | 28 | |
| 2883945193 | Myelin disorders: MS | demyleinating disease; caused by autoimmune inflammatory response -acons die to lack of neural activity -sensory and motor losses reflect region of neural damage *speech result: dysarthria | 29 | |
| 2884006821 | The synapse | -the space between neurons -presynaptic terminal--end of axon -synaptic cleft -postsynaptic terminal-receiving cell membrane | 30 | |
| 2884013237 | Transmissions across synapse | -usually chemical- due to neurotransmitters released from synaptic vessels at the end of terminal button -occasionally electrical-- immediate; no neurotransmitter involved allows neurons to fire in synchrony ex. neurons in medulla that control inspiration | 31 | |
| 2884029048 | Neurontransmitters | -Basis for chemical transmission of signal through the nervous system -have excitatory or inhibitory effects on postsynaptic membrane --> glutamate: most prevalent excitatory neurotransmitter --> amino butyric acid (gaba) most prevalent inhibitory neurotransmitter | 32 | |
| 2884041448 | Disorders of neurotransmitters: Parkinsons disease | -decrease in dopamine production due to death of cells in substantial nigra -produces resting trremor and difficulty with controlled movement | 33 | |
| 2884046312 | Disorders of neurotransmitters: Epilepsy | -over activity of glutamatergic neurons that lead to successive citation of too many neurons -anti seizure drugs work to increase GABA to inhibit neural firing | 34 | |
| 2884055807 | Disorders of neurotransmitters: Mysathenia Gravis | -Problem with neurotransmitters in motor system -neurotransmitter (acetylcholine) falls upon sustained muscle contraction -symptom: weakness upon sustained effort -in early stages of disease muscle function returns after period of rest and restoration of acetylcholine and NMJs | 35 | |
| 2884069149 | Primary neuronal loss | immediate degeneration | 36 | |
| 2884070879 | Secondary neuronal loss | -occurs after insult -highly variable, depends on blood flow, edema, inflammation, and the integrity of the blood brain barrier -after CVA occurs in region adjacent to insult | 37 | |
| 2884078343 | Adult CNS | -typically does not regenerate neurons --> exceptions: olfactory epithelium and hippocampus -->possibility: regeneration of neuron and when axon is damaged; typically with contacts to only nearby neurons -whole groups of cels can die off at once | 38 | |
| 2884085554 | Adult PNS | regeneration occurs following compression of peripheral nerve but if not severed. axon regrows at site of injury | 39 |