Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Psychobiology 1
Blocks 1-4
| Question | Answer |
|---|---|
| Neuron doctrine= | brain composed of individual, highly specialized cells (neurons) separated by functional space (synapses), not connected continuously as previously believed |
| 2 other names for "cell body" | soma, parikaryon |
| cellular fibers emerging from soma (2 types) unique to neurons | dendrites (multiple), axon (one) |
| if a neuron is "active," what is it doing? | releasing neurotransmitters |
| neurotransmitters are housed in ___ found in ___, located where on neuron? | synaptic vesicles, pre-synaptic terminals/boutons, tip of axon |
| Purpose/function of dendrites | input area- where neuronal information is received |
| neurotransmitters are released from __ and received onto specialized __ embedded in post-synaptic membrane of next cell | pre-synaptic terminal, NT receptors |
| What % of NTs actually naturally bind to receptors? | 10-15% |
| name specialized proteins embedded in membrane of pre-synaptic terminal that collects, binds, and transports unbound NTs back into pre-syn terminal for breakdown or re-use | re-uptake pumps |
| Prozac is an example of what and what is it's function and why is it useful? | SSRI (Selective Seratonin Re-uptake Inhibitor) which blocks re-uptake pumps so as to increase pool of available NTs by locking them in synapse |
| NEurons are characterized by how many neurites originate from soma- list different types (4) | bipolar, unipolar (sensory), multipolar (majority), pyrimidal (motor skills) |
| Which early neuroscientist developed Law of Dynamic Polarization, deducing neuronal function from neuron structure? | Ramon Cajal |
| When info flows from dendrite -> soma -> axon -> dendrite, this is passed through what sort of connection? | axodendritic synapse |
| info passed from axon -> soma through what connection? | axosomatic synapse |
| info passed from axon -> axon through what connection? | axoaxonic synapse |
| info passed form axon -> synaptic terminal through what connection? | axosynaptic synapse |
| T/F: cells can only be pre- or post- synaptic, but not both | False, all are both and can send/rcv info |
| What is the purpose of the neuronal membrane? | to separate intra- and extra- cellular environments |
| what do polar molecules (water for example) have, which organic, non-polar molecules (ex: carbon) do not? | electrical charge |
| opposite charges __, while like charges __. | attract, repel |
| organic/nonpolar molecules are "water-fearing" aka: | hydrophobicity (vs hydrophilicity) |
| Phospholipid= | phosphate (polar) head attached to lipid hydrocarbon (nonpolar tail: major component of nerve cell membranes) |
| Hydrophobic + hydrophilic regions= | amphipathic |
| 2 functions of proteins in neuronal membrane? | form hydrophilic channels/pumps, float (fluid mosaic) |
| DNA is to alphabet as protein is to ___ | words |
| Process of DNA -> RNA (production of an RNA copy of gene) is: | transcription |
| Process of RNA -> assembly of amino acids in specific order to make proteins: | Translation |
| Codes for specific amino acid sequence: | m(essenger)RNA |
| 2 roles of amino acids: | make up bigger proteins, act as NTs |
| 5 ways proteins are important for cell function | peptide hormones, NT transporters and receptors, NT channels and pumps, structural proteins, enzymes |
| In what way are peptide hormones different from NTs? | Released to blood stream as well as brain |
| Explain whether NT channels and pumps are active/passive | Channels are passive (allow movement of cell-moving salts), pumps are active (forces them in or out) |
| A protein is an enzyme if.. | it is a catalyst causing chemical reactions to create products from building blocks |
| PRocess of moving proteins and syn vesicles (NTs) from soma to pre-syn terminal is called (2 names) | Orthograde/Anterograde Axoplasmic transport |
| process of moving proteins and syn vesicles toward soma | Retrograde axoplasmic transport |
| Name of motor protein involved in anterograde transport | kinesin (very fast/efficient) |
| Name of motor protein involved in retrograde transport | dynein-dynactic |
| Goal of exocytosis | Release contents of loaded syn vesicles into syn |
| List 3 steps of exocytosis | 1. fusion of syn vesicle w/ plasma membrane 2. syn vesicle contents (hormonal signals/NTs) dumped into extracellular space 3. secretion |
| Explain process of endocytosis | piece of membrane pinches back to form new vesicle |
| when is exocytosis > endocytosis? purpose of this? | During neuronal growth, allows growth of axonic membrane in certain direction to connect with another neuron and form synapses |
| when is exocytosis < endocytosis? purpose of this? | during neuronal pruning, bad match with another neuron so withdraws to allow re-direction |
| when is exocytosis = endocytosis (functional balance)? | at a mature synapse/stable association between neurons |
| name the hypothesis which explains how neurites find their way during development? | chemoaffinity hypothesis |
| according to chemoaffinity hypothesis, what are the chemical signals used and what is their role in neuronal development? | trophic factors are released from neuron, if receptor is in vicinity, will feel gradient and put out own chemicals to guide growing neuron |
| name 2 trophic factors | NGF (nerve growth factor), BDNF (brain derived neurotrophic factor) |
| name the tip of a growing neuronal axon and explain how it changes | growth cone, sends out filopedia which flatten IF correct partner. Pre-/post- syn densities then appear (NT receptors/reuptake pumps) |
| explain neural plasticity in normal vs 2 abnormal forms | normal= signal:protein receptors= 1:1 down-regn= pre-syn cell inc trophic influence -> dec protein to protect from over-stim of post-syn cell up-reg= pre-syn cell dec trophic influence -> inc protein to have better chance of catching signal |
| what is prob w/ down reg? | post-syn cell = less sensitive to NT presence (ex. drug addiction- when off drug, dec in protein appears to be inability of function) |
| what is prob w/ up reg? | post-syn cell = supersensitive to any remaining NT presence (ex. phantom limb pain) |
| name regeneration cells in PNS and describe role: | Schwann cells- responsible for 1 axon, attach to neuron at site of injury -> sensitive scar tissue |
| name regeneration cells in CNS and describe role: | oligodendrocyte- can respond to damage but can't get to all -> damage to CNS neurons = permanent. Responsible for many axons. |
| molecules are formed by __, which differ by structure of pos charged __ and neg charged __ | atoms, nucleus, electrons |
| what is an ion? | atom that has either lost or gained a charge |
| describe chemical composition of intracellular environment of neuron | rich in potassium K+ like freshwater |
| describe chem composition of extracellular environment of neuron | rich in sodium Na+ like sea water, Cl- and Ca++ |
| Ion pore= __ in membranes which serve what purpose? | proteins, channel from out to inside so cells can function |
| name of 1 protein and name of many proteins together | monomer, polymer |
| name the 4 ions prevalent in intra/extra cellular env and abbrev | Sodium Na+, Potassium K+, Chloride Cl-, Calcium Ca++ |
| ___ describes the process of disorder/chaos in system, making it less organized (aka Diffusion) | Entropy |
| ___= principle of opposites attracting (developing -charge stops flow of +charge leaving) | Enthalpy |
| define equilibrium | point where enthalpy (electrostatic force) balances entropy (diffusion force) for any charged ion |
| nernst equation determines balance potential (aka ___ w/ abbrev) | Equilibrium Potential (Em) |
| Equilibrium potential= __ necessary to balance process of __ | Electrical charge (mV), diffusion |
| Ek (Equilibrium potential for Potassium)= ? (w/ interpretation) | -93mV -> inside of neuron must be 93mV more neg than outside for electrostatic force to balance diffusion force |
| an electrode measures __ (w/ abbrev) (aka resting potential) of a neuron, which is __ | membrane potential (Vm)= -70mV |
| a neuron can either __ or __ electrical charge | gain or lose |
| gaining pos charge -> upward deflection on oscilloscope= | depolarization |
| gaining neg charge -> downward deflection on oscilloscope= | hyperpolarization |
| define "force" of 3 ions on a neuron | "passive leak" across membrane= charge leaking in or out (K, Na, Cl) |
| T/F: If an ion leaks the most (high permeability), it has the most influence on charge? | True (resting potential (Vm) closer to Eq potential (Em) of K & Cl) |
| Order of permeability of 3 ions? | K, Cl, Na |
| what is the predominant energy-consuming process in brain and how it works? | sodium/potassium membrane pumps. Moves 3 sodium out and 2 potassium in to maintain ion gradient |
| name the electrically excitable domain | axon |
| what effect does neg elec signal have on axon | none, hyperpolarization equal to input |
| what effect does pos elec signal have on axon | depolarization into region of instability in current/voltage relationship -> action potential (AP) |
| Describe what AP looks like: | 1. reaches threshold (-60mV) 2. rapid depol -> almost reaches ENa (30-50mV= 'overshoot's 0) 3. rapid hyperpol -> almost reaches EK (-80mV= undershoots Vm) 4. gradual return of membrane potential to resting value (-70mV) |
| T/F: large amount of ions need to move for charge to change | False |
| define conductance of an ion and give abbrev | ability to move across membrane (gNa or gK etc) |
| describe AP in terms of ions and charge: | 1. gain 10mV charge 2. inward pos current (Na rushes in) 3. outward pos current (K rushes out) 4. excess K diffuses away |
| describe AP in terms of conductance: | 1. +10mV charge 2. -> inc gNa (voltage dependent) -> gNa turns self off (time dependent) 3. -> inc charge (more pos) -> inc gK (voltage dependent, less sensitive) |
| what happens to Na channels during AP? (gates) | 1. at rest, 2 gates closed 2. AP: depol -> physical re-shaping to unblock channel for only millisec (spring action timer) 3. inactivation gate closes and stays closed (refractory period) regardless of state of other gate/timer until K channels close |
| what are the differences between Na & K channels (how is K diff?) | 1. K has no inactivation gate, stays open until around Ek (-80mV) 2. Timer delays opening for 1 msec after depol |
| where on axon and in what direction does AP occur? | at nodes of ranvier, away from soma |
| how does Na & K return to original intra/extra cellular sites? | sodium/potassium pump (3 Na out, 2 K in) |
| name the other electrically excitable domain | pre-syn terminal (elect. signal triggers NT release) |
| what type of channel exists only at pre-syn term? | Ca |
| why is calcium an important piece of neuronal activity? | Entry to terminal facilitates NT release: -activates fusion of vesicle proteins and membranes proteins -> bind and release (exocytosis) -frees bound reserve vesicles to free pool |
| what calcium-dependent enzyme is present in terminal which aids in release of bound vesicles? | Kinase |
| what signals the postsyn potential | NTs binding to receptors |
| what is the chemically excitable domain | post syn region |
| what regulates ion conductance in chemically excitable domain? | presence of NTs -> chemical signal |
| postsyn potential= small and variable changes in __ produced by __-activated ion channels | membrane potential (Vm), transmitter |
| junction between soma and axon | axon hillock |
| EPSP function/role | conducive to AP (depol -> closer to threshold for AP) |
| IPSP function/role | prevents hillock from reaching threshold (hyperpol/block depol) |
| 2 ways to get excitatory effects (EPSP) | Increase gNa or gCa/ Decrease gK |
| how to get inhibitory effect (IPSP) | Increase gK or gCl |
| what happens when gCl is activated? | slightly depol (ECl= -66mV) but holds Vm near ECl and blocks depol influence |
Created by:
maryel99
Popular Science sets