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55 Cards in this Set
- Front
- Back
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What is an axon and what does it do?
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long extensions on neurons that enable them to conduct action potentials over long distances
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What are neurons and glia?
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Two parts of the nervous system, also known as nerve cells and glial cells.
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What is an action potential? What and when is it produced.
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A change in voltage across a membrane. It is produced by neurons and it happens when ion channels in the membrane open.
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What is the synapse and what forms it?
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Axon terminals form the synapse and it is the space between the axon of one neuron and the membrane of another.
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What is the Presynaptic neuron
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The neuron delivering information or the cell sending the message
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What is the postsynaptic neuron
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The neuron receiving information
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What are dendrites and what do they do?
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They are projections from the cell body that receive information and deliver it to the cell body.
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What is an axon and what does it do?
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It is the longest projection from the cell body and it delivers information to other cells
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What is the Axon terminal and what does it do?
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Axon terminals are on the bottom of the axon, spitting into parts. They form the synapse with a target cell.
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What is the Axon hillock and what does it do?
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It is the junction between the axon and the cell body. It is the site where the incoming signals are integrated and initiate an action potential down the axon.
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What are the 3 types of glia cells and where are they located?
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Oligodendrocytes (CNS), Schwann cells(PNS) and astrocytes (PNS)
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What do Oligodendrocytes and Schwann cells do?
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They wrap around the axons of neurons and cover them with Myelin.
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What is Myelin and what does it do?
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Myelin is the covering produced by the glia and it increases the rate of action potential transmission
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What are astrocytes and what do they do?
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They are glia that create the blood-brain barrier by surrounding the blood vessels in the brain. The blood barrier protects the brain from toxins
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What is the membrane potential?
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any difference in electric potential across the plasma membrane
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What is the resting potential?
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When the neuron is resting and not firing action potentials
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what are voltage-gated channels?
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Protein channels across the membrane that open or close in response to a change in the voltage across the plasma
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What happens when the plasma membrane is depolarized?
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Voltage gated Na+ channels open and the sodium enters the membrane and the inside of the cell becomes less negative.
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What happens when the plasma membrane is hyperpolarized
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The chemically gated K+ channel opens so more K+ ions go outside the cell causing the inside to be more negative or hyperpolarized.
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What are Neuromuscular junctions
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synapses between motor neurons and the skeletal muscle cells they innervate
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What is acetylcholine (Ach) and what does it do?
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it is a neurotransmitter used by all vertebrate motor neurons
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What does it mean if the synapses between neurons is excitatory
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When the neurotransmitters on the postsynaptic membrane always respond to ACh by depolarizing the postsynaptic membrane
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What does it mean if the synapses between neurons is inhibitory
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the response of the postsynaptic neuron is hyperpolarization
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Spatial summation
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signals form different neurons arrive at the hillock at the same time
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Temporal summation
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signals from the same neuron generated in rapid succession are summed
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What are Ionotropic receptors
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ion channels themselves
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What are metabotropic receptors
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not ion channels, but they induce signaling cascades in the postsynaptic cell that secondarily lead to changes in ion channels
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What are Metabolic pathways?
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a series of coupled, enzyme-catalyzed reactions wherein the the product of one reaction becomes the substrate for the next reaction
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What is the difference between aerobic and anaerobic?
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Aerobic uses O2
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What are the three characteristics of metabolic pathways?
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1. Individual reactions must be specific
2. The pathway itself must be thermodynamically favorable 3. Every pathway has a committed step |
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What is the committed step of a metabolic pathway?
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once the substrate passes this point, it must proceed through the entire pathway. It may or may not be the first reaction. It is highly exergonic making it irreversible and the regulation of pathway activity happens here
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What two paths can glucose take?
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It becomes 2 pyruvates and then it can either go through cellular respiration with oxygen and then go to the citric acid cycle and then the electron transport chain; or it can go through fermentation if O2 is absent and then become lactate or alcohol
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What is the most common electron donor and Acceptor in catabolic reactions?
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NAD
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What are the most reduced and least reduced molecules?
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Alkane, alcohol, aldehyde, carboxylic acid.
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What are the steps of aerobic paths?
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Glucose to glycolysis to pyruvate to cellular respiration.
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What are the types of enzymes in glycolysis in order?
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Hexokinase, Phosphohexose isomerase, phosphofructokinase, aldolase, isomerase, Triose Phosphate Dehyrogenase, Phosphoglycerate kinase, Phospho glyceromutase, Enolase, Pyruvate kinase.
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what is the commitment step for glycolysis
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Phosphofructkinase reaction
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What are the inputs of the citric Acid cycle? What are the outputs?
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Inputs: acetyl CoA, NAD, FAD, GDP
Outputs: 3 NADH, 1 FADH2, 1GDP, 2CO2 |
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What are the requirements for a regulatory system?
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Information: knowing what you are doing (feedback) and what you need to do (set point), effectors (controlled systems that bring about the desired change, regulatory systems: processes and systems that integrate info received by sensors, molecules that detect the error between the set point and actual values.
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What are the four types of tissues?
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Epithelial muscle nervous connective
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What are the two types of information delivered by sensors in the regulatory systems?
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Negative feedback: stabilizes systems, directing a return to the set point.
Positive feedback: amplifies a response |
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What do epithelial tissues do?
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Cover inner and outer surfaces such as skin and the gut. They are sheets of tightly packed cells barriers, detectors and filtration/transport.
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What are the types of muscle tissues and what do they do?
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They contract to generate forces and cause movement. They are skeletal, cardiac, smooth.
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What do connective tissues do?
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They are the cartilage and bone which lines joints and makes up the structures of ears and noses.
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What is the difference between endotherms, ectotherms, and heterotherms?
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Endotherms produce heat metabolically, ectotherms primarily depend on environmental temperatures to control body temperature and Heterotherms switch between both.
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how does an endotherm keep its body temp constant?
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By increasing or decreasing its metabolic rate. (warmer increases)
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What is radiation
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When heat transfers form warmer objects to cooler ones via the exchange of infrared radiation.
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What is Conduction
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When heat transfers directly when objects of two different temperatures come into contact.
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What is convection
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Heat transfers to a surrounding medium such as air or water as that medium flows over a surface.
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What is evaporation
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Heat transfers away from a surface when water evaporates on that surface.
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what is the thermoneutral zone
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when the metabolic rate of endotherms is low and independent of temperature.
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What are sensory cells and what do they do?
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sensory cells are modified neurons specialized to detect external and internal stimuli and transmit that info to the cns
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What do ionotropic sensory receptors do?
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responsible for opening ion channels and changing the membrane potential
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What do metabotropic sensory receptors do?
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they are linked to the production of a second messenger which is responsible for triggering ion channel opening.
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what are mechanoreceptors?
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sensory cells that respond to mechanical forces.
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