Podcast
Questions and Answers
What are the 3 general classes of neurons?
What are the 3 general classes of neurons?
- Sensory (afferent) Neurons (correct)
- Interneurons (correct)
- Motor (efferent) Neurons (correct)
- Glial Cells
What specialized function do sensory (afferent) neurons serve?
What specialized function do sensory (afferent) neurons serve?
They detect changes in the environment called stimuli.
Where do interneurons lie and what is their function?
Where do interneurons lie and what is their function?
They lie within the CNS and receive signals from other neurons to carry out integrative functions.
What is the primary function of motor (efferent) neurons?
What is the primary function of motor (efferent) neurons?
What does the Central Nervous System (CNS) consist of?
What does the Central Nervous System (CNS) consist of?
What does the Peripheral Nervous System (PNS) consist of?
What does the Peripheral Nervous System (PNS) consist of?
What does the somatic nervous system innervate?
What does the somatic nervous system innervate?
What function does the autonomic nervous system control?
What function does the autonomic nervous system control?
What is the soma of a neuron?
What is the soma of a neuron?
What are dendrites?
What are dendrites?
What does the axon hillock do?
What does the axon hillock do?
What are multipolar neurons?
What are multipolar neurons?
What is the defining characteristic of bipolar neurons?
What is the defining characteristic of bipolar neurons?
What is unique about unipolar neurons?
What is unique about unipolar neurons?
What are anaxonic neurons?
What are anaxonic neurons?
What is axonal transport?
What is axonal transport?
What is anterograde transport?
What is anterograde transport?
What is retrograde transport?
What is retrograde transport?
What is neuroglia?
What is neuroglia?
What do oligodendrocytes do?
What do oligodendrocytes do?
What are abundant astrocytes?
What are abundant astrocytes?
What role do protoplasmic astrocytes have?
What role do protoplasmic astrocytes have?
What do fibrous astrocytes provide?
What do fibrous astrocytes provide?
What is the function of ependymal cells?
What is the function of ependymal cells?
What are microglia?
What are microglia?
What do Schwann cells do in the PNS?
What do Schwann cells do in the PNS?
What are satellite cells responsible for?
What are satellite cells responsible for?
All axons in the PNS have a sheath of ______ cells around them.
All axons in the PNS have a sheath of ______ cells around them.
What is myelin?
What is myelin?
How does the speed of nerve signal travel depend?
How does the speed of nerve signal travel depend?
What is necessary for the regeneration of peripheral nerve fibers?
What is necessary for the regeneration of peripheral nerve fibers?
What is an electrical potential?
What is an electrical potential?
What does it mean when cells are polarized?
What does it mean when cells are polarized?
What is the resting membrane potential of neurons?
What is the resting membrane potential of neurons?
What characterizes a local potential?
What characterizes a local potential?
What generates an action potential?
What generates an action potential?
What does the refractory period signify?
What does the refractory period signify?
What characterizes signal conduction in unmyelinated fibers?
What characterizes signal conduction in unmyelinated fibers?
What did Otto Loewi discover about neurotransmitter communication?
What did Otto Loewi discover about neurotransmitter communication?
What roles do presynaptic neurons play?
What roles do presynaptic neurons play?
What characterizes postsynaptic neurons?
What characterizes postsynaptic neurons?
What is synaptic transmission?
What is synaptic transmission?
What happens during cessation of the signal?
What happens during cessation of the signal?
What are neuromodulators?
What are neuromodulators?
What is neural integration?
What is neural integration?
What is excitatory postsynaptic potential (EPSP)?
What is excitatory postsynaptic potential (EPSP)?
What is inhibitory postsynaptic potential (IPSP)?
What is inhibitory postsynaptic potential (IPSP)?
What is the nature of glutamic and aspartic acid?
What is the nature of glutamic and aspartic acid?
What role does glycine play in neurotransmission?
What role does glycine play in neurotransmission?
What is summation in neural physiology?
What is summation in neural physiology?
What is facilitation in neural activity?
What is facilitation in neural activity?
What is presynaptic inhibition?
What is presynaptic inhibition?
What is neural coding?
What is neural coding?
What are neuronal pools?
What are neuronal pools?
What is a neuronal circuit?
What is a neuronal circuit?
What is the basis of memory in neuroscience?
What is the basis of memory in neuroscience?
Study Notes
Neuron Classes
- Sensory (afferent) Neurons: Detect environmental changes (stimuli).
- Interneurons: Integrate signals within the CNS, facilitating communication between neurons.
- Motor (efferent) Neurons: Transmit signals to muscles and glands for bodily responses.
Nervous System Structure
- Central Nervous System (CNS): Comprises the brain and spinal cord, consisting of gray matter and white matter.
- Peripheral Nervous System (PNS): Includes nerves extending to and from the CNS.
Nervous System Divisions
- Somatic Nervous System: Controls skeletal muscle movements.
- Autonomic Nervous System: Regulates cardiac and smooth muscle functions.
Neuron Anatomy
- Soma: Neuron's control center containing the nucleus and organelles.
- Dendrites: Extensions that receive signals via neurotransmitter receptors.
- Axon Hillock: Site of action potential initiation.
Types of Neurons
- Multipolar Neurons: Most common, with one axon and multiple dendrites.
- Bipolar Neurons: One axon and one dendrite, primarily found in sensory organs.
- Unipolar Neurons: Contain a single process from the soma.
- Anaxonic Neurons: Multiple dendrites but no distinct axon.
Axonal Transport
- Axonal Transport: Two-way movement of materials along the axon.
- Anterograde Transport: Movement away from the soma via kinesin protein.
- Retrograde Transport: Movement toward the soma.
Glial Cells
- Neuroglia: Supportive cells in the nervous system, with six distinct types.
- Oligodendrocytes: Form myelin sheaths around CNS neurons.
- Astrocytes: Star-shaped, assist in forming the blood-brain barrier and provide structural support.
- Ependymal Cells: Produce and circulate cerebrospinal fluid.
- Microglia: Immune cells in the CNS, act as macrophages.
- Schwann Cells: Create myelin sheaths in the PNS, aiding in neuron regeneration.
- Satellite Cells: Surround PNS neuron cell bodies; function is less understood.
Myelin and Nerve Fibers
- Myelin Sheath: Composed of Schwann cells, enhancing signal conduction speed.
- Unmyelinated Fibers: Associated with Schwann cells, but signal travels slower.
- Regeneration: Possible in PNS if the neurilemma and soma are intact.
Electrical Potentials
- Resting Membrane Potential (RMP): Neurons are polarized at -70 mV; maintained primarily by the sodium-potassium pump.
- Local Potentials: Small, graded deviations in RMP that can be excitatory or inhibitory.
Action Potentials
- Action Potential Generation: Requires sufficient depolarization at the axonal hillock.
- Phase Changes: Rapid depolarization followed by repolarization; involves sodium and potassium ion channels.
- Refractory Period: Includes absolute and relative stages, defining the neuron's responsiveness following an action potential.
Signal Conduction
- Unmyelinated Fibers: Impulses travel at slower speeds (up to 2 m/sec).
- Saltatory Conduction: In myelinated fibers, action potentials jump between nodes of Ranvier, increasing speed (up to 120 m/sec).
Neurotransmission
- Discovery: Communication through synapses, first identified by Otto Loewi, with acetylcholine as the first neurotransmitter.
- Synaptic Transmission: Involves release of neurotransmitters, receptor binding, and generation of postsynaptic potentials (PSP).
- Neuromodulators: Substances modifying synaptic transmission and receptor expression.
Neural Processing
- Neuronal Integration: Mechanisms of information processing and memory based on neurotransmitter effects.
- Facilitation and Inhibition: Processes that enhance or suppress synaptic transmission.
Memory and Plasticity
- Memory Trace (Engram): Pathways formed by new or modified synapses.
- Types of Memory: Immediate, short-term, and long-term memory, with declarative and procedural categories.
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Description
This quiz covers the different classes of neurons, including sensory, interneurons, and motor neurons. It also explores the structure of the nervous system, including the central and peripheral nervous systems, and the components that make up each type of neuron. Test your knowledge on the organization and function of neurons and their role in the nervous system.
