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Neurons and Neurotransmitters
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- 1Neurons (Def.)- Basic units of the nervous system
- Cells that receive, integrate, and transmit info in the nervous system - 2How do neurons communicate?- They communicate with each other through chemical signals
- They operate internally by electrical impulses - 3Central Nervous System (CNS) contains?Consists of the brain and the spinal cord, both contain massive numbers of neurons
- 4Neural Networks (Def.)Neurons that communicate selectively with other neurons to form neural networks
- 5Peripheral Nervous System (PNS) contains?- All nerve cells in the body that are not part of the CNS
- The PNS includes the somatic and autonomic nervous systems - 6What does the PNS do?The PNS sends info to the CNS
- 7What does the CNS do?The CNS organises and evaluates info from the PNS and directs the PNS to perform specific behaviours
- 8Sensory Neurons (Def.)These neurons detect info from the physical world and pass that info to the brain, usually through the spinal cord
- 9Motor Neurons (Def.)These neurons direct muscles to contract or relax, producing movement
- 10Interneurons (Def.)These neurons communicate within local or short-distance circuits, integrate neural activity with a single area rather than transmitting info to other organs
- 11Reflexes (Def.)- Automatic motor responses that occur before we think about the response
- Neurons simply convert sensation into action - 12Dendrites (Def.)Branchlike extensions of the neuron that detect info (chemical signals) from other neurons
- 13Cell Body (Def.)The site in the neuron where info from thousands of other neurons is collected and integrated
- 14Axon (Def.)Electrical impulses are transmitted down a long, narrow outgrowth known as the axon, and they can vary in length.
- 15Terminal Buttons (Def.)At the ends of axons, small nodules that release chemical signals from the neuron into the synapse
- 16Synapse (Def.)- The gap between the axon of a "sending" neuron and the dendrites of a "receiving" neuron
- The site where chemical communication occurs between neurons - 17Membrane of Neuron (Def.)- A fatty barrier that does not dissolve in the watery environment inside and outside the neuron
- Semipermeable
- Regulates concentration of electrically charged molecules - 18Ion Channels (Def.)Specialised pores that allow ions to pass in and out of the cell when the neuron transmits signals down the axon
- 19Resting Membrane Potential (Def.)The difference between the electrical charge inside and outside a neuron when it is not active
- 20What is the charge inside and outside a neuron when it is not active?The inside of an inactive neuron is slightly more negative than the outside
- 21Polarised (neurons)- When a neuron has more negative ions inside than outside
- This creates the electrical energy necessary to power the firing neuron - 22What type of ions are involved in the polarisation of a neuron?- Sodium ions are positively charged
- Potassium ions are negatively charged - 23Sodium-Potassium Pump (Def.)The pump increases potassium and decreases sodium inside the neuron, helping to maintain the resting membrane potential
- 24Action Potential (Neural Firing) (Def.)The electrical signal that passes along the axon and causes the release of chemicals from the terminal buttons
- 25Excitatory Signals (Def.)Depolarize the cell membrane, these signals increase the likelihood that the neuron will fire
- 26Inhibitory Signals (Def.)Hyperpolarize the cell, these signals decrease the likelihood that the neuron will fire
- 27When is an action potential generated?If the total amount of excitatory input surpasses the neuron's firing threshold and the neuron is depolarized
- 28Myelin Sheath (Def.)A fatty material, made up of glial cells, that insulates some axons to allow for faster movement of electrical impulses along the axon
- 29Nodes of Ranvier (Def.)- Small gaps of exposed axon, between the segments of myelin sheath, where action potentials take place
- Action potentials pause briefly at each node to recharge - 30All-or-None Principle (Def.)- The principle that when a neuron fires, it fires with the same potency each time. A neuron either fires or not.
- A neuron will fire more frequently is the stimulation is strong - 31Presynaptic Neuron (Def.)The neuron that sends the signal
- 32Postsynaptic Neuron (Def.)The neuron that receives the signal
- 33Neurotransmitters (Def.)- Chemical substances that transmit signals from one neuron to another
- These chemicals are made in the axon and are stored in vesicles - 34Receptors (Def.)- Specialised protein molecules on the postsynaptic membrane
- Neurotransmitters bind to these molecules after passing across the synapse - 35Reuptake (Def.)The process whereby a neurotransmitter is taken back into the presynaptic terminal buttons, thereby stoping its activity
- 36Enzyme Deactivation (Def.)Occurs when an enzyme destroys the neurotransmitter in the synapse
- 37Autoreceptors (Def.)- Monitor how much neurotransmitter has been released into the synapse
- When an excess is detected, the autoreceptors signal the presynaptic neuron to stop releasing the neurotransmitter - 38Antagonists (Def.)Drugs and toxins that inhibit the actions of neurotransmitters
- 39Agonists (Def.)Drugs and toxins that enhance the actions of neurotransmitters
- 40Acetylcholine (ACh) (functions)- Motor control over muscles
- Learning, memory, sleeping, and dreaming - 41Botulinum Toxin (Def.)This neurotoxin inhibits the release of acetylcholine (ACh), resulting in paralysis of muscles and often death
- 42Epinephrine (functions)- A monoamine neurotransmitter
- Energy - 43Norepinephrine (functions)- A monoamine neurotransmitter
- Arousal, vigilance, and attention - 44Serotonin (functions)- A monoamine neurotransmitter
- Emotional states and impulsiveness
- Dreaming - 45Dopamine (functions)- A monoamine neurotransmitter
- Reward and motivation
- Motor control over voluntary movement - 46GABA (gamma-aminobutyric acid) (functions)- Primary inhibitor of action potentials
- Anxiety reduction - 47Glutamate (functions)- Primary excitator of action potentials
- Learning, memory - 48Endorphines (functions)- Neurotransmitters involved in natural pain reduction and reward
- 49Selective Serotonin Reuptake Inhibitors (SSRIs)A drug that blocks serotonin reuptake and thus leaves more serotonin at the synapse to bind with the postsynaptic neurons
- 50Parkinson's Disease- A degenerative and fatal neurological disorder marked by muscular rigidity, tremors, and difficulty initiating voluntary action
- Lack of dopamine may be involved in movement problems - 51Deep Brain StimulationInvolves surgically implanting electrodes deep within the brain and then using mild electrical stimulation in the regions affected by Parkinson's disease
Información
- Descripción
- Definitions of types of neurons, and neurotransmitters. Definitions of the parts of neurons, and how they work.
- Creado por
- Steph M
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