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43 Cards in this Set
- Front
- Back
What are the obstacles for studying the cells of the nervous system? |
1) Size 2) Nervous tissue/cells are like jello, so we need to harden them to make sections for slides 3) Cells are transparent and need to be stained to be visualized |
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What was the first identified neuron, why, and where do we find them? |
Pukinje cells because they're huge cerebellum neurons |
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Describe the first identified neuron |
Purkinje Cells are some of the largest neurons with a long axon and a giant dendritic tree. I'm talking massive **** here. |
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What are the 2 stains used to identify nervous system cells? How do they differ in their staining ability? |
Nissl staining stains glial cells and cell bodies ONLY
Golgi staining stains all of the neuron, but unfortunately only like 15-20% of cell density |
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What is the benefit of golgi staining? |
It shows the entire dendritic tree and orientation of the neuron relative to others |
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Who published a paper on silver nitrate staining and believed in the reticular theory of the brain? What is the reticular theory? |
Camillo Golgi. Reticular theory means all neurons are physically connected in a net as a giant continuous system |
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Who one-upped Golgi's stainng procedure then killed his stupid little reticular thoery? What was proposed instead? How was this theory flawed too? |
Cajal improved golgi's staining and described nerves as independent elements thus founding the neuron doctrine. He was close, but we described neurons are communicating via contact not continuity. |
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This "Sir" came along after Cajal and Golgi shared their nobel prize in 1906 and finally got it right by proposing the concept of ______ as a place of communication for neurons. Who am I and what did I propose? |
Sir Charles Sherrington proposed the synapse and walked away with a nobel in medicine in 1932 |
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What is the function of the sensory neuron and define nerve. |
Sensory neurons bring information to the CNS and nerves include blood vessels + bundles of neural axons |
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How can we differentiate between an axon and a dendrite? |
Axons can branch out at any point whereas dendrites can only branch at their ends |
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What cells are found in the cortex that can communicate with cells above or below, and laterally with other cells? |
Pyramidal cells thanks to the apical and lateral axons |
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Describe thalamic association cells? |
Has a ton of dendrites all around it. Kinda looks like a ball of hair? |
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What neurons have some of the largest axons and why? |
Motor neurons since they go from the spine out to the muscle |
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How do dendrites differ from terminals? |
Dendrites don't have terminal buttons |
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How can we differentiate unipolar and bipolar neurons? |
By the number of neurites! |
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Sensory neurons are __erent whereas motor neurons are __erent |
Sensory are afferent whereas motor are efferent |
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Name the 7 important structures of a neurons internal structure |
1) Nucleus 2) Dendritic Spines 3) Endoplasmic reticulum 4) Ribosomes 5) Mitochondria 6) Golgi Apparatus 7) Microtubules |
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Describe dendritic spines. What is the advantage of dendritic spines? |
Have a head and neck to a spine. Usually have a synapse. Spines are a way for cells to process diff. inputs |
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Neurofilaments confer ___ to a cell |
Strength |
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What are the 4 CNS support cells. What is the umbrella term for these cells that provide physical support, control nutrient flow, and are involved in phagocytosis? |
1) Astrocytes 2) Microglia 3) Oligodendrocyte 4) Schwann Cells |
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What cells are responsible for physical support, debris removal, and nutrient transport to neurons? |
Astrocytes |
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What cells are involved in phagocytosis and brain immune function? |
Microglia |
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How do oligodendrocytes differ from Schwann cells? |
Oligodendrocytes are only found in the CNS and can myelinate multiple cells simultaneously via arm-like extensions of itself. Schwann cells are only in the PNS and the entire cell wraps around the neuron and becomes myelin. |
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What does the BBB separate? Where is the BBB weakest and why? |
BBB separates blood and the brain by producing cells that line the walls of the brain's capillaries. The BBB is weakest at the area postrema which is in the medulla and acts as a poison detector since it can initiate vomiting. |
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Define and quantify resting membrane potential. |
Difference in electronic potential between inside and outside of the cell. It's usually -70mV |
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K+ is found in highest concentrations ____ the axon, whereas Cl- and Na+ are found in highest concentrations ____ the axon |
K+ inside, Cl- and Na+ outside |
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Describe the action of the sodium-potassium pump |
2 K+ into the cell for every 3 Na+ out of the cell |
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Is a pump is electrogenic, what does that mean? |
It produces a separation of charge
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What are 2 properties of passive conduction? |
It's fast and degrades over distance |
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What are the 6 steps of an action potential? |
1) Na+ channels open 2) K+ channels open 3) Na+ channels become refractory and close for 2-3ms 4) K+ leaves the cell as membrane potential returns to resting levels 5) K+ channels close and Na+ channels reset 6) Extra K+ outside the neuron diffuses away and we hyperpolarize |
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Define rate law |
Stronger signals produce higher firing rates at a fixed amplitude |
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How do action potentials differ from local disturbances? |
Action potentials don't degrade over distance unlike local disturbances |
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Conduction velocity is proportional to what property of a neuron? |
Axon diameter and myelination |
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Why do we need nodes of ranvier? |
There is decremental conduction going on under the myelin sheath which is a gradual decrease in the stimuli and response along a pathway of conduction. Nodes of ranvier serve to kick up this signal back to it's full amplitude. |
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What is the function of axonal cisternae? What organelle at these associated with? |
Cisternae recycle vesicles and are part of the golgi apparatus |
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Define Axosomatic synapse |
When a terminal of 1 neuron attached to the soma of another |
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Why is the postsynaptic membrane thicker? |
It's higher concentration of receptors |
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What is the function of an axoaxonal synapse? |
These are usually inhibitory but serve to regulate amount of neurotransmitter being released |
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How does a vesicle interact with the presynaptic membrane to release NT into the synaptic space? |
1) Action potential opens voltage dependent Ca2+ channels 2) Ca2+ interact with vesicle and membrane proteins allowing for fusion 3) Vesicle fuses as omega figures and releases NT |
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How does a post-synaptic potential differ from an action potential? |
1) Post-synaptic potentials can be graded and summated, whereas action potentials are all or nothing at an invariable magnitude 2) Action potentials are generated by voltage-gated channels whereas local potentials are generated by chemically-dependent channels, usually NT |
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How do we make a "bigger" post-synaptic potential? |
1) Increase concentration of receptor 2) Increase concentration of NT |
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What is neural integration? |
The algebraic summation of post synaptic potentials |
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Which type of ion channel requires energy input and is also slower? |
Metabotropic
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