Questions and Answers
What is the primary function of sensory neurons?
Which type of neuron is primarily involved in coordinating movement and glandular secretions?
Which type of glial cell is responsible for maintaining the blood-brain barrier?
What distinguishes Golgi type I neurons from Golgi type II neurons?
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What is a key role of microglia in the nervous system?
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Which glial cell type is primarily accountable for myelination in the peripheral nervous system (PNS)?
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What is the process called when astrocytes proliferate after neuronal death?
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Which of the following describes the function of satellite cells in the PNS?
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What is the primary function of dendrites in a neuron?
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Where are the nuclei of nerve cell bodies located?
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What term describes the rapid transmission of nerve impulses along myelinated axons?
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What structure is responsible for carrying nerve impulses away from the cell body?
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Which classification of neurons has a single process that splits into two branches?
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What is the primary role of axon transport in neurons?
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What type of neuron is specialized to receive input from a specific sensory receptor?
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Which part of a neuron contains the nucleus and essential organelles?
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Study Notes
Neurons/Nerve Cells
- Specialized cells for transmitting nerve impulses and communicating via synapses.
- Electrically excitable nature facilitates communication with other cells.
Dendrites
- Tree-like extensions from the soma acting as primary receivers of information.
- Collect signals from other neurons at synaptic junctions.
Cell Body/Soma/Perikaryon
- Central part of the neuron containing the nucleus and essential organelles.
- Control center for neuron’s life, ensuring proper functioning.
- Nuclei found within the CNS; ganglia located outside the CNS.
Axon/Nerve Fiber
- Functions as an electric cable transmitting action potentials from the cell body.
- Axolemma: membrane of the axon; Axoplasm: cytoplasm of the axon.
- Saltatory conduction allows rapid nerve impulse transmission along myelinated axons, jumping at Nodes of Ranvier.
- Axon transport includes orthograde (away from the cell body) and retrograde (towards the cell body) transport.
- Telodendria are fine, branching extensions at the axon’s end, transmitting impulses away from the cell body.
Anatomical Classification of Neurons
- Unipolar/Pseudounipolar Neurons: Single process splitting into peripheral and central branches; primarily sensory neurons in the PNS.
- Bipolar Neurons: Two processes (one axon, one dendrite); specialized to receive input from specific sensory receptors.
- Multipolar Neurons: One axon and multiple dendrites allow input from multiple neurons and transmission to various targets.
Functional Classification of Neurons
- Sensory Neurons (Afferent): Carry signals from sensory receptors to the CNS, informing about the environment.
- Interneurons: Integrate sensory information, relay signals, and contribute to cognitive functions like learning and memory.
- Motor Neurons (Efferent): Transmit signals from the CNS to muscles and glands, coordinating bodily functions.
Relative Lengths of Axons and Dendrites
- Golgi Type I: Short, numerous dendrites; long axons (up to one meter) connecting different CNS parts.
- Golgi Type II (Microneurons): Axons resemble dendrites morphologically, giving a star-like appearance.
Neuroglia/Glial Cells
- Non-neuronal cells crucial for supporting neuron health and activity.
- Provide essential functions for maintaining nervous system health.
Glial Cells in the CNS
- Astrocytes: Offer structural support, maintain the blood-brain barrier, regulate neurotransmitters, supply nutrients, and remove waste.
- Oligodendrocytes: Produce myelin in the CNS for insulation.
- Microglia: Act as immune cells for the brain, engulfing pathogens and debris.
- Ependymal Cells: Line brain ventricles and spinal canal; produce and circulate cerebrospinal fluid (CSF).
- After neuron death, astrocytes proliferate in a process called replacement gliosis.
- Glioblastoma multiforme, a lethal brain tumor, arises from astrocytes and has a life expectancy of 2-3 months.
Glial Cells in the PNS
- Schwann Cells: Responsible for myelination in the PNS.
- Satellite Cells: Surround neuron cell bodies in PNS, providing structural support and regulating the local microenvironment.
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Description
Test your knowledge on neurons, dendrites, and the structure of nerve cells with this quiz. Learn about specialized cell functions and the connections that facilitate communication in the nervous system. Perfect for biology students studying neuroscience or related fields.
