Questions and Answers
What is the primary role of neurons within the nervous system?
Which cells within the nervous system are responsible for supporting neurons?
Approximately how many neurons are found in the human brain?
Which of the following is not a component of the nervous system?
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What distinguishes neurons from other cell types within the nervous system?
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Which part of a motor neuron is responsible for attaching to muscle fibers?
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Which of the following is found in both motor neurons and sensory neurons?
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Where are sensory endings specifically located in sensory neurons?
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Which structure is directly involved in the transmission of neural signals in motor neurons but not explicitly depicted for sensory neurons?
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Which of the following parts is unique to the motor neuron compared to the sensory neuron?
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What is an example of how temporal summation works in postsynaptic integration?
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How do transporters terminate synaptic activity?
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How does cocaine influence synaptic activity?
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Which statement best describes spatial summation?
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What role do astrocytes play in terminating synaptic activity?
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Which part of the neuron contains synaptic vesicles?
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What is the primary function of dendrites?
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Where does the axon typically leave the cell body?
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What is the main component within the nucleus of a neuron?
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Which theory suggested that neurons are continuous with one another?
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What is the role of the selectively permeable membrane around the cell body?
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Which type of neuron is primarily responsible for conducting information between neurons in the same area?
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Which type of neuron has a single short stalk from the cell body that divides into two branches?
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Where are sensory neurons primarily located?
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What is the form and location of motor neurons?
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What type of neuron has short axons that communicate locally?
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Which type of neuron conducts messages from the brain and spinal cord to muscles and organs?
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Which type of neuron characteristically has dendrites and an axon extending from both ends of the cell body?
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Which type of neuron has multiple dendrites and a single axon extending from the cell body?
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What is the primary role of an excitatory postsynaptic potential (EPSP)?
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Which of the following best describes the effect of increased polarization or hyperpolarization on a neuron's likelihood of firing an action potential?
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What is the primary function of sodium-potassium pumps in the cell membrane?
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Which neurotransmitter deficiency is related to epileptic seizures?
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Which of the following ion movements occur during depolarization of a neuron?
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What primary function do oligodendrocytes and Schwann cells share?
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Which type of neural signal is responsible for within-cell communication?
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What primarily causes the negative resting membrane potential of a neuron?
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How can an EPSP affect a neuron that has an inhibitory effect on other neurons?
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Which type of glia is primarily responsible for aiding neuron migration in embryonic development?
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What happens immediately after a neuron's membrane becomes depolarized during an action potential?
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What role do astrocytes play in neuron function?
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Why is the distinction between EPSP and IPSP important in the context of treatments like Ritalin for ADHD?
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Which type of neural transmission is associated with carrying information away from a structure?
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What is the characteristic of an action potential that distinguishes it from other types of electrical signals?
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Which process is NOT involved in the generation of an action potential?
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Which function is primarily performed by microglia in the nervous system?
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Which of the following ions is the cell membrane permeable to during the resting condition?
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What potential is typically measured at -70mV in a neuron?
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What type of potential is initiated at postsynaptic sites on dendrites and the cell body?
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Which membrane structure serves as ion channels and receptor molecules?
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Which of the following best describes the permeability of a neuron membrane during resting conditions?
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Which neurotransmitter is derived from the amino acid tyrosine and is involved in arousal and stress responses?
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What does the binding of GABA to GABA-A receptors result in?
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Which criterion must a chemical substance meet to be classified as a neurotransmitter?
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Which neurotransmitter is involved in mood regulation, arousal, impulsivity, aggression, appetite, and anxiety?
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What is the primary role of GABA as a neurotransmitter?
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Which of the following correctly describes a peptide neurotransmitter?
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Study Notes
Introduction to Neuroscience
- Neuroscience is the study of the nervous system, which consists of the brain, spinal cord, and nerve cells.
- The nervous system is composed of two main types of cells: neurons and glia.
- Neurons are specialized for communication, while glia provide support for neurons.
- The human brain contains approximately 80-100 billion neurons.
Neuron Structure
- The three main parts of a neuron are the dendrites, cell body, and axon.
- Dendrites receive chemical messages from other neurons.
- The cell body contains the nucleus and other structures, wrapped by a selectively permeable membrane.
- The axon is a long, slender process that carries information from the cell body to the terminal buttons.
- Terminal buttons contain synaptic vesicles that release neurotransmitters into the synapse.
Types of Neurons
- Motor neurons conduct messages from the brain and spinal cord to muscles and organs.
- Sensory neurons carry information from the body and world to the brain and spinal cord.
- Interneurons conduct information between neurons in the same area.
Neuron Function
- Neurons transmit information through electrical and chemical signals.
- Spatial summation combines potentials occurring simultaneously at different locations on the dendrites and cell body.
- Temporal summation combines potentials arriving a short time apart, from either the same or separate neurons.
Synaptic Activity
- When an action potential reaches the terminal button, neurotransmitters are released into the synapse.
- Neurotransmitters bind to receptors on the postsynaptic neuron, causing a change in the electrical properties of the neuron.
- Reuptake is the process by which neurotransmitters are taken back into the terminal buttons by membrane proteins (transporters).
Excitation and Inhibition
- Excitation is the process by which a neuron is made more likely to fire an action potential.
- Inhibition is the process by which a neuron is made less likely to fire an action potential.
- Both excitation and inhibition are equally important for proper neural function.
Resting Potential
- The resting potential is the electrical state of a neuron at rest, with a negative charge on the inside compared to the outside (-70mV).
- The resting potential arises from a combination of electrostatic forces, ion concentration gradients, and selective permeability.
- Sodium-potassium pumps help maintain the electrical gradient.
Action Potential
- An action potential is a brief electrical impulse that travels along an axon and allows one neuron to communicate with another.
- The action potential is possible due to the semi-permeable membrane, which maintains chemical and electrical gradients across the membrane.
- Depolarization changes the voltage, which may cause voltage-sensitive ion channels to open and allow ionic diffusion.
- The action potential is an all-or-none event.
Glia
- Glia are the other major component of the nervous system, providing support for neurons.
- Astrocytes help synchronize the activity of the axon by wrapping around the presynaptic terminal and taking up chemicals released by the axon.
- Microglia remove waste material and other microorganisms that could prove harmful to the neuron.
- Oligodendrocytes and Schwann cells build the myelin sheath that surrounds the axon of some neurons.
- Radial glia guide the migration of neurons and the growth of their axons and dendrites during embryonic development.
Neurotransmitters
- Neurotransmitters are chemical substances released synaptically from one neuron that affect another cell in a specific manner.
- There are three general categories of neurotransmitters: amino acids, amino acid-derived, and peptides.
- Examples of neurotransmitters include GABA, dopamine, norepinephrine, serotonin, and peptides.
Cell Membrane
- The cell membrane is formed from two layers of lipid molecules with proteins "floating" within the bilayer.
- The cell membrane is selectively permeable, allowing certain molecules to pass through while keeping others out.
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Description
This quiz covers the basic components of motor and sensory neurons, including their structures and functions. Test your knowledge of neuron anatomy and get started with neuroscience!