Term
| At rest, what excess charges lie inside and outside of the cell? |
|
Definition
| There is an excess of positive charge on the outside of the cell, and an excess of negative charge on the inside of the cell |
|
|
Term
| Cystolic proteins are translated on free what? |
|
Definition
|
|
Term
| Do glial cells cause action potentials? |
|
Definition
| No, they have ion channels, ion pumps, transmitter receptors, and a membrane potential. They produce and respond to neurotransmitters, but do not form AP's and are not polarized. |
|
|
Term
| Draw a schematic of a typical neuron: |
|
Definition
|
|
Term
| Draw and label the Neuron and Epithelial Cell |
|
Definition
|
|
Term
| Draw the electrical equivalent circuit model for examining the effects of axial and membrane resistance as well as capacitance |
|
Definition
|
|
Term
| Draw the equivalent electrical circuit model of the membrane |
|
Definition
|
|
Term
| How can you determine the mean opening times for ion channels? |
|
Definition
|
|
Term
| How can you speed up the conduction velocity? |
|
Definition
| Increase the length constant and decrease the time constant |
|
|
Term
| How can you test if gap junctions exist between cells? |
|
Definition
| Use a dye to see if dye spreads from 1 cell to another |
|
|
Term
| How do input resistance and capacitance affect the membrane potential? |
|
Definition
| As the cell gets bigger, rm decreases because more ion channels are present. As capacitance increases, the potential has a harder time changing because it has more ability to hold charge. |
|
|
Term
| How do you calculate axial resistance with Rin and the length constant? |
|
Definition
|
|
Term
| How do you calculate rm from Rin and the length constant? |
|
Definition
|
|
Term
| How do you calculate the change in the membrane voltage over time? |
|
Definition
| Vm = Im*Rin*(1-exp(-t/tau)) |
|
|
Term
| How do you calculate the input resistance given Rm, Ra, and the axon diameter? |
|
Definition
| Rin = 1/2*sqrt(Rm*Ra/(2*pi^2*a^2)) |
|
|
Term
| How do you calculate the length constant with the axon radius, Rm, and Ra? |
|
Definition
|
|
Term
| How do you calculate the specific membrane resistance, Rm, and specific axial resistance, Ra? |
|
Definition
Rm = rm*2*pi*a
Ra = ra*pi*a^2 |
|
|
Term
| How do you calculate the total current crossing the membrane given the ionic current (Ii) and capacitive current (Ic)? |
|
Definition
|
|
Term
| How does axon diameter affect the input resistance and length constant? |
|
Definition
| Input resistance and axon diameter are inversely related. The length constant and axon diameter are directly related |
|
|
Term
| How does current flow through an axon? |
|
Definition
| It flows longitudinally along the axon and leaks out through the membrane. |
|
|
Term
| Is passive efflux of K+ and influx of Na+ through resting channels of equal size? |
|
Definition
| No, there are different numbers of these channels, so to make sure the charges are balanced, the channels must be different sizes. |
|
|
Term
| List 4 techniques that led to the discovery of axonal transport: |
|
Definition
*Paul Weiss tied off sciatic nerve and observed accumulation of axoplasm proximal to the ligature
*Radioactive labeling of neuronal proteins
*video enhanced DIC light microscopy
*Fluorescence labeling techniques combined with photobleaching and photoactivation |
|
|
Term
| List 5 ways to identify neurons and connections: |
|
Definition
*Golgi silver staining
*Injecting fluorescent markers such as lucifer yellow and dextran
*Apply virus particles that are taken up by the nerve terminal
*GFP-Expression
*Labeling with immunocytochemistry |
|
|
Term
| List 6 characteristics of axons: |
|
Definition
*Only one of them per cell body
*1 micro meter to 1 meter in length
*Special initiated segment
*MT are orientated with (+) end towards the terminal
*Not many organelles found in axons |
|
|
Term
| List 6 characteristics of dendrites: |
|
Definition
*Many of them per cell body
*Generally shorter than axons
*Continuous with the cell body
*Not myelinated
*Mixed polarity of MTS (microtubules)
*More organelles are found in dendrites |
|
|
Term
| List 7 different organelles |
|
Definition
| Nucleus, Endoplasmatic Reticulum (ER), Golgi Complex, Vesicles, Endosomes, Lysosomes, and Mitochondria |
|
|
Term
| List 8 functions of glial cells? |
|
Definition
*Myelin Sheath for signal propagation: oligodendrocytes in the CNS and Schwann Cells in the PNS.
*Immune Function Scavengers: microglia
*Blood Brain Barrier (BBB): astrocytes
*Nutrition Lactate Fromastrocytes: Neuron
*Synaptic Formation: Astrocytes
*Homeostasis/Control of Neural Environment: Astrocytes
*Production of growth factors and ECM Proteins: Extracellular Matrix
*Guiding Neurons and axons: radial glia |
|
|
Term
| List four facts about Neurons |
|
Definition
*10^11 neurons in the brain
*Main signaling unit in the nervous system
*Same organelles as other cells
*Polarized cell |
|
|
Term
| List the 5 Co- and Posttranslational modifications that are important for proper localization and functions of proteins: |
|
Definition
| Phosphorylation, Ubiquitination, Glycoslyation, N-acylation, and Isoprenlation |
|
|
Term
| List the six types of macroglia cells |
|
Definition
*Astrocytes (CNS)
*Oligodendrocytes (CNS)
*Ependymal Cells (CNS)
*Radial Glia (CNS)
*Schwann Cells (PNS)
*Satellite cells (PNS) |
|
|
Term
| Most complex organ system of the body |
|
Definition
|
|
Term
| Secretory and membrane proteins are synthesized by what? |
|
Definition
|
|
Term
| This gal really knows how to pump out your oil |
|
Definition
|
|
Term
| True or False, extracellular and intracellular solutions are electrically neutral? |
|
Definition
| True, as long as the cell is in a resting state |
|
|
Term
| True or False, ions can pass freely through the membrane? |
|
Definition
| False, they can not because of selective permeability |
|
|
Term
| True or False, the total concentration of particles inside and outside the cell are equal? |
|
Definition
| True, as long as the cell is in a resting state |
|
|
Term
| What 3 things are possible because of the multiple protein synthesis locations? |
|
Definition
*Synapse-specific, long-term facilitation of Aplysia sensory to motor synapses: function for memory formation.
*Chemotropic guidance responses of retinal growth cones mediated by rapid local protein synthesis and degradation
*Intra-axonal protein synthesis during axonal regeneration from adult sensory neurons |
|
|
Term
| What are 3 important ion channel features? |
|
Definition
*Found in excitable cells, neurons, muscles cells, and endocite cells
*Structure from 2-pass membrane subunits to more complex multipass/multisubunit proteins
*Selectively permeable |
|
|
Term
| What are characteristics of Charge, Q? |
|
Definition
| 1 Coulomb, C. 1 proton = 1.6E-19 C |
|
|
Term
| What are four different shapes neurons can take on, and what are there geometries? |
|
Definition
*Unipolar - Many dendrites that can act as an axon (invertebrates)
*Bipolar Cell - Dendrites on one side 1 axon on the other (retival cells)
*Pseudo-unipolar: 2 axons, no dendrites (sensory neurons in ganglia)
*Multipolar: Many many dendrites and 1 axon (Purkinje fibers) |
|
|
Term
| What are glutamate receptors? |
|
Definition
*Glutamate is the most important excitatory NT in the CNS
*Can be ionotropic or metabotropic |
|
|
Term
| What are some biological processes that depend on ion channels? |
|
Definition
*Neuronal signaling
*Muscle contraction
*Hormone secretion
*regulation of salt and water balance
*fertilization prevention of polyplodine
*Sensory transduction
*Cell proliferation |
|
|
Term
| What are some characteristics and functions of microtubules? |
|
Definition
This subsystem of the cytoskeleton has:
*Important for axonal growth and guidance
*Provide tracks for long-range protein and organelle transport between neuronal cell body and the nerve terminal |
|
|
Term
| What are some characteristics and functions of the plasma membrane? |
|
Definition
This component of the cell has:
*asymmetric lipid bilayer with proteins
*hydrophobic barrier impermeable to most water-soluble molecules
Function:
*Important for maintaining specific ion, metabolite, transmitter concentrations in the intra- and extra- cellular compartments |
|
|
Term
| What are some characteristics of Capacitance? |
|
Definition
| how well can a surface hold a charge, unit: 1 Farad (F), C = Q/V. describes how much charge can be stored on an object at a specific voltage |
|
|
Term
| What are some characteristics of Conductance? |
|
Definition
| (g), g = 1/V, Unit is 'g' which is 1 siemen(s), describes how well current flows in response to a certain voltage |
|
|
Term
| What are some characteristics of Neurofilaments? |
|
Definition
*10 nm wide stable intermediate filaments
*Most abundant fibrillar components in axon that provide strength
*Determine the axon caliber and are modified in Alzheimer's disease and other degenerative disorders such as ALS |
|
|
Term
| What are some characteristics of Voltage? |
|
Definition
| Electrical potential difference, V => Volt, V = N*m/C |
|
|
Term
| What are some characteristics of action potentials? |
|
Definition
This propagation method has:
*Large amplitude (70-100 mV)
*Brief duration (1-10 ms)
*Amplitude is constant, frequency reflects stimulus intensity
*All or nothing event
*Can travel long distances (3 meters) at high speed (120 m/s) |
|
|
Term
| What are some characteristics of ligand-activated ion channels? |
|
Definition
*Trasduce a chemical signal into an electrical signal
*Channels are activated when NTs attach
*Low degree of ion selectivity
*channel activation is pretty slow |
|
|
Term
| What are some characteristics of local graded potentials? |
|
Definition
*Small amplitude: (0.1 - 10 mV)
*Variable duration: (ms to min)
*Amplitude and duration in proportion to stimulus
*Passive propagation
*Travel only short distances (1-2 mm) |
|
|
Term
| What are some functions and characteristics of the Cytoskeleton? |
|
Definition
This subset of the cytosol:
*is responsible for cell division, shape determination, motility and organelle transport
*Contains microtubules, actin filaments, and neurofilaments
*Associated proteins account for 25% of the neuronal protein
*Tubulin is 10% of total brain protein; brain is often used as a source for tubulin purification |
|
|
Term
| What are some functions of Schwann Cells? |
|
Definition
These macroglial cells:
*Insulate axons with myelin in the PSN; one schwann cell wraps one axon |
|
|
Term
| What are some functions of astrocytes? |
|
Definition
This macroglial cell is:
*Most abundant glial cell type
Functions: Structural support, control chemical environment of neurons, take up potassium after extensive neuron firing, transmitter uptake from synaptic cleft, supply neurons with nutrients, glial end feet (Regulate development in the BBB) |
|
|
Term
| What are some functions of oligodendrocytes? |
|
Definition
| Insulate axons with myelin in CNS; one oligodendrocyte can wrap several axons |
|
|
Term
| What are some functions of radial glia cells? |
|
Definition
These macroglial cells:
*Are important for CNS development
*Form elongated fibers between ventricular and marginal zone along which neurons migrate to their final destination |
|
|
Term
| What are some functions of the Ependymal Cells? |
|
Definition
This macro glial cell:
*Lines the cavities of the CNS and makes up the walls of the ventricles
*Beat their cilia to help circulate the cerebrospinal fluid (CSF)
*CSF removes harmful metabolites and has a cushion function |
|
|
Term
| What are the 5 components/classes of rate for axonal transport? |
|
Definition
| Fast anterograde, bi-directional, fast retrograde, slow component 'a', and slow component 'b' |
|
|
Term
| What are the characteristics of current? |
|
Definition
| Charge/time, C/sec = 1 Ampere (A). Current equals net flow of charge in the direction of (+) charge movement |
|
|
Term
| What are the equations for calculating: Current, Conductance, Resistance, Capacitance, NERST, Goldman, Simplified Goldman, Time Constant, and Length Constant? |
|
Definition
|
|
Term
| What are the four different recording configurations with patch clamping? |
|
Definition
*Cell attached - single channel recording with control of outside milieu
*Inside-out patch - single channel recording and control of inside and outside milieu
*Whole cell recording - strong suction and control inside milieu
*Outside-out patch - single channel recording and control of inside and outside milieu |
|
|
Term
| What are the four functionally defined regions of the neuron? |
|
Definition
| Cell body, Dendrites, Axon, and Presynaptic Terminal |
|
|
Term
| What are the four modes of activations for ion channels? |
|
Definition
*Voltage gated: Na+ channels 10^4 times more selective for Na+ than K+
*Stretch-activated: Ca+ channel
*Ligand activated: extracellular - NTs, acetylcholine receptors; intracellular - CGMP activated Na+ Channels |
|
|
Term
| What are the four signaling components of the neuron? |
|
Definition
*Input components: dendrites and cell bodies
*Trigger Components: axon hillock
*Conductive Component: axon
*Output Component: Presynaptic Terminal |
|
|
Term
| What are the functions of F-actin? |
|
Definition
This subsystem of the ctyoskeleton:
*Provides structural support
*Growth cone motility and guidance
*Bidirectional tracks for short-range protein and organelle transport: plus end and minus end organelle transport by myosin motor proteins |
|
|
Term
| What are the mechanisms that drive the sodium-potassium pump? |
|
Definition
| One molecule of ATP is hydrolyzed, causing the large membrane spanning protein pump to pump out three NA+ ions and brings in two K+ ions to maintain the resting potential. This causes a net outward current |
|
|
Term
| What are the three functional classifications of neurons? |
|
Definition
| Sensory Neurons, Motor Neuron, Interneuron |
|
|
Term
| What are the three passive properties that are important to electrical signaling? |
|
Definition
*Membrane resistance, rm - resistance across the membrane
*Axial (internal) resistance, ra (ri) - resistance along the inside of the axon
*Membrane capacitance, cin (cm) - Input capacitance |
|
|
Term
| What are the three synapses of the neuron? |
|
Definition
| Presynaptic terminal, presynaptic cleft, and post synaptic dendrite |
|
|
Term
| What are the two different signaling types? |
|
Definition
*Passive - for receptor potentials, small amplitudes (0.1-10) mV, duration (ms to min), and can hyperpolarize of depolarize
*Active - for Action Potentials, Large amplitude (70-100) mV, brief duration (1-10) ms, and depolarizing effect only |
|
|
Term
| What are the two ways that uneven ion distribution across the membrane is achieved? |
|
Definition
*Membrane is selectively permeable to certain ions
*Pumps for Na+ and K+ |
|
|
Term
| What are three areas that have evidence of protein synthesis? |
|
Definition
| Axon, terminals, and growth cones from various neuronal systems |
|
|
Term
| What are three important concepts of the NERST eqns? |
|
Definition
*NERST only applies to single ions that move through the membrane
*Equilibrium potential of a particular ion is the membrane potential at which there is no net movement in permeability
*Absolute change in [K+] in and out of the cell is very small (~0.001%) |
|
|
Term
| What are three ways neurons speed up electrical signal propagations? |
|
Definition
*Myelin sheaths speed up propagation. As myelination increases, rm increases
*Increasing the axon dia, ra decreases
*Decreasing cm |
|
|
Term
| What are three ways that neuronal polarity is maintained? |
|
Definition
| Selective delivery of proteins, Selective Fusion of membranes, Selective retention of proteins |
|
|
Term
| What are two driving forces that cause ion transport? |
|
Definition
*Chemical driving force - concentration gradient.
*Electrical driving force - Electrical potential difference |
|
|
Term
| What are two especially important features of neurons? |
|
Definition
*Membrane has to be excitable electrically
*Polarized cell |
|
|
Term
| What are two important concepts of neuronal organelles? |
|
Definition
*All organelles found in the cell body can be found in the dendrites
*Not all organelles found in the axon |
|
|
Term
| What are two main classes of glial cells? |
|
Definition
*Microglia: small, mesoderm-derived, central nervous system
*Macroglia: larger, ectoderm-derived, CNS and PNS |
|
|
Term
| What are two reasons why its important to know the structure of ion channels? |
|
Definition
|
|
Term
| What are two things that influence the resting potential? |
|
Definition
| Ion concentration ratios, and the conductance of the membrane |
|
|
Term
| What are two types of motors associated with microtubules? |
|
Definition
Kinesin Motors: mediate either plus or minus end-oriented transport
Dynein Motors: minus end-oriented transport |
|
|
Term
| What causes neurons and other excitable cells to have a membrane potential? |
|
Definition
| Charge separation from the lipid bilayer causes an unequal distribution of ions. |
|
|
Term
| What configuration of the passive properties of electrical signaling should be seen to promote fast signaling? |
|
Definition
| High Membrane resistance, low axial resistance, and low Cm because of the time constant |
|
|
Term
| What did Ramon y Cajal contribute to Science? |
|
Definition
| They utilized Golgi's silver staining technique to show that neurons are single cells that don't form a syncytium. |
|
|
Term
| What do ion channels allow? |
|
Definition
| They allow diffusion through the membrane down their electrochemical gradient |
|
|
Term
| What do migrating neurons ultimately form? |
|
Definition
| The migration will lead to the development of dendritic neurons |
|
|
Term
| What do pumps and transporters do? |
|
Definition
| They use energy to move ions and other molecules across the membrane against the electrochemical gradient |
|
|
Term
| What does the NERST eqn reduce to at 37 degress C? |
|
Definition
|
|
Term
| What does the NERST eqn reduce to at Room Temp? |
|
Definition
|
|
Term
| What does the addition of a few Na+ do to the cell? |
|
Definition
| Depolarizes the membrane slightly |
|
|
Term
| What does the input resistance determine in terms of voltage? |
|
Definition
| It determines the peak voltage. |
|
|
Term
| What does the time constant represent? |
|
Definition
| The product of the input resistance and capacitance of the membrane (Rin*Cin). It determines the time when the potential reached 1-1/e = 63% of its final value. |
|
|
Term
| What exchange of (+) ions balances inward current into the cell? |
|
Definition
| Potassium outward current is balanced by sodium inward current |
|
|
Term
| What happens the the cell is positive charge is removed from the cell? |
|
Definition
| It hyperpolarizes, no AP will occur. |
|
|
Term
| What happens to the cell if a positive current is injected into it? |
|
Definition
| It depolarizes. Enough depolarization will cause an AP. |
|
|
Term
| What happens to the different currents on the electrical equivalent circuit when different currents are added? |
|
Definition
|
|
Term
| What ion channels are responsible for NT release? |
|
Definition
|
|
Term
| What ion channels are responsible for depolarizing during AP? |
|
Definition
| Voltage-activated sodium channels |
|
|
Term
| What ion channels are responsible for repolarizing during AP? |
|
Definition
| Voltage gated K+ channels |
|
|
Term
| What ions are ion channels permeable too? |
|
Definition
Cations - K+, Na+, and Ca+2
Anions - Cl- |
|
|
Term
| What is Fast retrograde transport? |
|
Definition
| This transport of endosomes, vesicles, and mitochondria is driven by dyneins and moves around 200-400 mm/day |
|
|
Term
|
Definition
| Membrane association of the protein |
|
|
Term
|
Definition
|
|
Term
|
Definition
| Case where several nerve and muscle diseases are due to defects in ion channels. Ex - Long QT Syndrome (caused by mutations in voltage-gated K+ channels) |
|
|
Term
| What is a function Golgi Complex? |
|
Definition
| Modification of proteins; and sorting and targeting proteins |
|
|
Term
| What is a function of lysosomes? |
|
Definition
|
|
Term
| What is a function of mitochondria? |
|
Definition
| Produce ADP and energy, calcium storage |
|
|
Term
| What is a function of the endoplasmic reticulum (ER)? |
|
Definition
| Rough ER synthesize proteins and Smooth ER synthesize lipids and steroids, metabolize carbohydrates and steroids (but not lipids), and regulate calcium concentration, drug metabolism, and attachment of receptors on cell membrane proteins. |
|
|
Term
| What is electrical signaling? |
|
Definition
| short changes from the membrane resting potential due to current flow through ion channels |
|
|
Term
| What is equation for the length constant? |
|
Definition
|
|
Term
| What is fast anterograde transport? |
|
Definition
| This transport moves around 200-400 mm/day, is derived from the Golgi vesicles and mitochondria is driven by kinesins |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
| What is one main function of a neuron? |
|
Definition
|
|
Term
|
Definition
| Take a glass micropipette and attach it to the neuronal membrane with a slight suction to result in a giga ohm seal to record currents through the membrane |
|
|
Term
|
Definition
| Signaling/regulating protein function |
|
|
Term
|
Definition
| Unit is the ohm, R, R = V/I. Resistance of an object to current |
|
|
Term
| What is slow axonal transport a? |
|
Definition
| This transport moves neurofilaments and tubulin at 0.3-3 mm/day |
|
|
Term
| What is slow axonal transport b? |
|
Definition
| This transport moves actin and actin-associated proteins, cytosolic enzymes at 2-8 mm/day |
|
|
Term
| What is the 6 step pathway of a neuropeptide? |
|
Definition
*Synthesis in ER; Modification in ER
*Modification and targeting in Golgi
*Formation of large dense core vesicles (neuropeptides) and synaptic vesicle precursors
*Axonal transport
*Formation of synaptic vesicles in terminal uptake and release of NTs; release of secretory proteins
*Endosomal recycling: retrograde transport of large dense core vesicles, refill of synaptic vesicles with NTs |
|
|
Term
| What is the Goldman Equation, and what does it represent? |
|
Definition
| It is the constant field equation at room temperature: Vm = 58mV * log((Pk*[Ko] + Pna*[Nao] + Pcl*[Cli])/(Pk*[Ki] + Pna*[Nai] + Pcl*[Clo])) |
|
|
Term
| What is the NERST equation in words and what is the formula? |
|
Definition
| NERST is the electrical potential between the outside and inside at which there is no net movement of ions. This is the equilibrium potential. E = RT/zF*ln[Xo/Xi] |
|
|
Term
| What is the axon's main function? |
|
Definition
| This neuron region is responsible for conducting information |
|
|
Term
| What is the cell body's function? |
|
Definition
| This neuron region is responsible for metabolic function, protein synthesis, and receiving signals from other neurons |
|
|
Term
| What is the driving force and permeability situation for Na+? |
|
Definition
| There is a strong driving force, but a low permeability for Na+ |
|
|
Term
| What is the equation for input resistance? |
|
Definition
|
|
Term
| What is the equilibrium potential for chlorine? |
|
Definition
|
|
Term
| What is the equilibrium potential of K+ in a mammalian neuron? |
|
Definition
|
|
Term
| What is the equilibrium potential of Na+? |
|
Definition
|
|
Term
| What is the equivalent circuit for examining the effects of membrane capacitance? |
|
Definition
|
|
Term
| What is the function of the endosomes? |
|
Definition
| Recycle material from outside the cell |
|
|
Term
| What is the function of the nucleus? |
|
Definition
|
|
Term
| What is the function of the presynaptic terminal? |
|
Definition
| This neuron region is responsible for converting electric signal to chemical signal. |
|
|
Term
| What is the function of the vesicles? |
|
Definition
| Deliver protein from membranes |
|
|
Term
| What is the ion concentration of Calcium inside and outside of a mammalian neuron? |
|
Definition
| 0.0001 mM inside the cell and 1-2 mM outside of the cell |
|
|
Term
| What is the ion concentration of Calcium inside and outside of the squid neuron? |
|
Definition
| 0.0001 mM inside the cell and 10 mM outside of the cell |
|
|
Term
| What is the ion concentration of Chloride inside and outside of a mammalian neuron? |
|
Definition
| 4-30 mM inside and 110 mM outside |
|
|
Term
| What is the ion concentration of Chlorine inside and outside of the squid neuron? |
|
Definition
| 40-150 mM inside the cell and 560 mM outside the cell |
|
|
Term
| What is the ion concentration of Potassium inside and outside of the squid neuron? |
|
Definition
| 400 mM inside and 20 mM outside |
|
|
Term
| What is the ion concentration of Sodium inside and outside of a mammalian neuron? |
|
Definition
| 5-15 mM inside and 145 mM outside |
|
|
Term
| What is the ion concentration of Sodium inside and outside of the squid neuron? |
|
Definition
| 50 mM inside and 440 mM outside |
|
|
Term
| What is the ion concentration of potassium inside and outside of a mammalian neuron? |
|
Definition
| 140 mM inside and 5 mM outside |
|
|
Term
| What is the length constant word definition? |
|
Definition
| It is the distance from the site of current injection, where the potential reaches 1/e or 37% of its original value at the site of injection. Typical length constants for mammalian axon is 0.5-1 mm. |
|
|
Term
| What is the main function of dendrites? |
|
Definition
| This neuron region is responsible for receiving information |
|
|
Term
| What is the main function of the interneuron? |
|
Definition
| This classification of the neuron is for connecting neurons. |
|
|
Term
| What is the main function of the motor neuron? |
|
Definition
| This classification of neurons is responsible for send information to effector muscles |
|
|
Term
| What is the main function of the sensory neuron? |
|
Definition
| This classification of neurons receives information from periphery |
|
|
Term
| What is the orientation of MTs in axons and dendrites? |
|
Definition
In axons: MT are oriented towards the growth cone
In dendrites: MT plus ends are oriented either towards the cell body of the growth cone/synapse |
|
|
Term
| What is the relationship between K+ and Na+'s driving forces and conductance? |
|
Definition
| K+ has a small net outward force and a large conductance. Na+ has a large net inward driving force and a small conductance |
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Term
| What is the relationship between voltage and distance from the excitation point? |
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Definition
| V(x) = V0*exp(-x/gamma), where gamma is the length constant |
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Term
| What is the resting membrane potential with and without looking at Chlorine? |
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Definition
| with Cl-: -68.3 mV. without Cl-: -65 mV |
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Term
| What is two main function of glial cells? |
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Definition
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Term
| What two motors drive fast axonal transport? |
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Definition
| This transport is driven by kinesin and dynein molecular motors |
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Term
| What were Cajal's major contributions to his discovery about neurons? |
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Definition
*Neurons are single distinct cells
*signal travels in one direction
*Connectional specificity
*Neurons have distinct shapes - led to the identification of the growth cone |
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Term
| What were Hodgkin and Katz's contributions to their discoveries? |
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Definition
| They determined how extracellular ion concentrations affect the membrane potential. They fit their data to Goldman's equation and found the ratios of permeabilities |
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Term
| Where does protein translation occur? |
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Definition
| Most of it occurs in the cell body, but there is evidence that some happens in the axon and nerve endings |
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Term
| Which lady in our class can used to be able to make things get bigger? |
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Definition
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Term
| Which pretty lady has the sexiest stomach? |
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Definition
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Term
| Who is Julius Bernestein and what did he do? |
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Definition
| He formulated the "membrane hypothesis" stating that an unequal K+ ion concentration inside and outside of the cell could cause the resting membrane potential. He proposed that during excitation another positive ion entrs the cell, counteracting the diffusion potential of potassium ions. He was unsuccessful in measuring membrane potentials accurately however |
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Term
| Who is in your bed... even when your not? |
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Definition
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Term
| Who is the wealthiest person in BME, both monetarily and in wisdom? |
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Definition
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Term
| Who was responsible for discovering the NERST eqn? |
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Definition
| Walter Nerst - German Physicist and chemist Nobel Prize in Chemistry |
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Term
| Who were A.L. Hodgkin, A.F. Huxley, and B. Katz, and what did they do? |
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Definition
| They used the giant squid axons that innervate the mantle of the squid for electrical recordings. This allowed them to determine how changing the ion concentration affects the membrane potential. |
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Term
| Who were Erwin Neher and Bert Sakmann and what did they do? |
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Definition
| They developed the patch clamping technique |
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Term
| Why does the capacitance of the membrane slow down the change in membrane potentials in response to ionic currents? |
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Definition
| The capacitance influences the time constant, that describes how quickly the membrane potential reaches its final level. |
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Term
| Why is endocytosis important in neurons? |
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Definition
| Reuptake of NTs, controlling the number of receptors on the surface, and keeping the neuron at a specific size |
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Term
| Why is the resting membrane potential not -89 mV? |
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Definition
| There is sodium leakage into the cell which causes the potential to be around -65 mV. |
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Term
| Why is there a significant change in the permeability of Na+ during an action potential? |
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Definition
| Opening of voltage-gated sodium channels that respond to depolarization of the membrane |
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Term
| Why is there a slight influx of Cl- that gets counterbalanced and ultimately moved out of the cell? |
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Definition
| This is because the potential of Cl- is more negative that the membrane resting potential. |
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