Podcast
Questions and Answers
Which type of neuron conveys information to the CNS?
Which type of neuron conveys information to the CNS?
Which type of gated channel opens in response to a chemical stimulus?
Which type of gated channel opens in response to a chemical stimulus?
Resting membrane potential is defined as the positive charge inside a neuron.
Resting membrane potential is defined as the positive charge inside a neuron.
False (B)
Neuroglia cells are electrically excitable like neurons.
Neuroglia cells are electrically excitable like neurons.
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What are the two types of neuroglia found in the PNS?
What are the two types of neuroglia found in the PNS?
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What type of ion channels open in response to pressure, touch, or vibration?
What type of ion channels open in response to pressure, touch, or vibration?
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Oligodendrocytes function in the CNS by producing __________.
Oligodendrocytes function in the CNS by producing __________.
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The unequal distribution of ions across a neuron's membrane is primarily managed by the __________.
The unequal distribution of ions across a neuron's membrane is primarily managed by the __________.
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Match the following types of neuroglia with their primary function:
Match the following types of neuroglia with their primary function:
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What primarily causes the negative charge inside a resting neuron?
What primarily causes the negative charge inside a resting neuron?
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Match the types of ion channels with their activation stimuli:
Match the types of ion channels with their activation stimuli:
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Which neuron type processes sensory information and elicits a motor response?
Which neuron type processes sensory information and elicits a motor response?
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Schwann cells are responsible for producing myelin in the CNS.
Schwann cells are responsible for producing myelin in the CNS.
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Graded potentials occur only in axons of neurons.
Graded potentials occur only in axons of neurons.
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What defines a graded potential?
What defines a graded potential?
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What is the primary function of astrocytes in the CNS?
What is the primary function of astrocytes in the CNS?
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What determines the amplitude of a graded potential?
What determines the amplitude of a graded potential?
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Graded potentials can increase in amplitude by being added together.
Graded potentials can increase in amplitude by being added together.
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What are the two phases of an action potential?
What are the two phases of an action potential?
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An action potential occurs only if the membrane potential reaches __________.
An action potential occurs only if the membrane potential reaches __________.
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Match the types of potentials with their characteristics:
Match the types of potentials with their characteristics:
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Which type of ion channels are primarily involved in action potentials?
Which type of ion channels are primarily involved in action potentials?
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Action potentials are propagated over short distances and decay in strength.
Action potentials are propagated over short distances and decay in strength.
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What type of channel is responsible for the initial depolarization in an action potential?
What type of channel is responsible for the initial depolarization in an action potential?
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What is the primary function of Action Potentials?
What is the primary function of Action Potentials?
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Graded Potentials can allow communication over long distances.
Graded Potentials can allow communication over long distances.
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What determines the production of Action Potentials and Graded Potentials?
What determines the production of Action Potentials and Graded Potentials?
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The channels that respond to chemical stimuli are known as ______ channels.
The channels that respond to chemical stimuli are known as ______ channels.
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Match the type of ion channel to its description:
Match the type of ion channel to its description:
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Which ion channel type is most abundant in neurons?
Which ion channel type is most abundant in neurons?
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All excitable cells have the same type of ion channels.
All excitable cells have the same type of ion channels.
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What is the role of voltage-gated channels in neurons?
What is the role of voltage-gated channels in neurons?
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What is the primary function of summation in neuronal communication?
What is the primary function of summation in neuronal communication?
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Temporal summation involves multiple presynaptic inputs occurring at the same time.
Temporal summation involves multiple presynaptic inputs occurring at the same time.
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Name one type of small molecule neurotransmitter.
Name one type of small molecule neurotransmitter.
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_________ is known to inhibit pain impulses by suppressing the release of substance P.
_________ is known to inhibit pain impulses by suppressing the release of substance P.
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Which of the following is NOT classified as a neuropeptide?
Which of the following is NOT classified as a neuropeptide?
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Match the following neuropeptides with their primary role:
Match the following neuropeptides with their primary role:
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Spatial summation involves a single presynaptic input occurring at different times.
Spatial summation involves a single presynaptic input occurring at different times.
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What are biogenic amines classified as?
What are biogenic amines classified as?
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Which neuropeptide is primarily responsible for regulating hunger and is associated with the stress response?
Which neuropeptide is primarily responsible for regulating hunger and is associated with the stress response?
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The hypothalamic releasing hormones solely have an excitatory effect on the anterior pituitary.
The hypothalamic releasing hormones solely have an excitatory effect on the anterior pituitary.
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What is the primary function of angiotensin II in the brain?
What is the primary function of angiotensin II in the brain?
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In the CNS, the limited ability for neurons to regenerate is primarily due to inhibitory influences from __________.
In the CNS, the limited ability for neurons to regenerate is primarily due to inhibitory influences from __________.
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Match the neuropeptide with its associated function:
Match the neuropeptide with its associated function:
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What type of neural circuit consists of a single pathway for information flow?
What type of neural circuit consists of a single pathway for information flow?
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Regeneration of nervous tissue is highly effective and common throughout the central nervous system.
Regeneration of nervous tissue is highly effective and common throughout the central nervous system.
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What does plasticity in the nervous system refer to?
What does plasticity in the nervous system refer to?
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Study Notes
Nervous Tissue
- The nervous system is a complex network in the body responsible for maintaining homeostasis and health.
- It is composed of different branches, and various cell types.
- The nervous system's purpose is to understand how it maintains health and homeostasis, identify and describe different nervous system branches and the different cell types that make up nervous tissue.
Nervous System Overview
- Sensory neurons carry information to the central nervous system.
- Interneurons are found in the brain or spinal cord.
- Motor neurons carry information from the central nervous system.
Nervous System Organization
- The central nervous system (CNS) includes the brain and spinal cord.
- The peripheral nervous system (PNS) includes cranial nerves, spinal nerves, enteric plexuses, and sensory receptors in skin.
- The PNS is further subdivided into the sensory and motor divisions.
- The motor division is further divided into the somatic nervous system (voluntary control of skeletal muscle) and the autonomic nervous system (involuntary control of smooth and cardiac muscle, and glands).
- Within the autonomic nervous system, are further divisions: sympathetic and parasympathetic.
Functions of the Nervous System
- Sensory function: detects changes (stimuli) in or outside the body.
- Integrative function: analyzes sensory information, stores some aspects or aspects, and makes decisions related to appropriate behaviors.
- Motor function: responds to stimuli by activating effectors—muscles or glands.
Histology of Nervous Tissue
- Neurons are electrically excitable cells.
- Neurons are the cellular units found in nervous tissue.
- Neuroglia cells (Glia) are also found in nervous tissue.
- Neuroglia cells do not generate impulses, but support, insulate and protect neurons. Glial cells make up half the volume of nervous tissue.
- Other features of nervous tissue include, myelin sheath. myelinated axons and unmyelinated axons
Neurons
- Neurons are electrically excitable cells.
- A nerve impulse is an action potential.
- Neurons have different structures(parts) like dendrites, cell body, axon etc
Structural Classification of Neurons
- Multipolar neurons have many processes that extend from the cell body.
- Bipolar neurons have two processes that extend from the cell body.
- Pseudounipolar neurons have one process that extends from the cell body, but splits into two branches.
Functional Classification of Neurons
- Sensory neurons convey information to the central nervous system.
- Motor neurons convey information from the central nervous system.
- Interneurons process sensory information and elicit a motor response.
Neuroglia
- Neuroglia support neurons in many ways in the central and peripheral nervous system.
- Neuroglia are not excitable.
- In the central nervous system (CNS), there are four types of neuroglia: (1) Astrocytes; (2) Oligodendrocytes; (3) Microglia; (4) Ependymal cells.
- In the Peripheral Nervous System (PNS), there are two types of neuroglia: (1) Satellite cells; (2) Schwann cells
Myelination of Neurons
- The myelin sheath is produced by Schwann cells (PNS) and oligodendrocytes (CNS).
- Myelin sheath surrounds the axons of most neurons; it increases speed of AP propagation
Gray Matter vs. White Matter
- Gray matter contains neuron cell bodies and dendrites.
- White matter contains myelinated axons.
Electrical Signals in Neurons (Action Potential)
- Excitable cells communicate through action potentials
- Resting membrane potential
- Action potentials occur when a stimulus causes a membrane to reach threshold.
Graded Potentials
- Gradual potentials. These potentials determine the strength of the initial stimulus
- These are brief changes in membrane potential that can be depolarizing or hyperpolarizing.
- Graded potentials generally decreases in strength over time
Ion Channels
- Leak channels: Open/close randomly
- Ligand-gated: Open in response to ligand.
- Mechanically-gated: Open in response to physical changes.
- Voltage-gated: Open in response to voltage changes.
Resting Membrane Potential
- The inside of the neuron—specifically the axon—is negative compared to the outside.
- This difference results from different concentrations of ions (sodium, potassium, etc.) inside versus outside.
- This difference in charge is maintained, in part, by the sodium-potassium pump and other ion channels through the cell membrane.
Postsynaptic Potentials (PSP)
- Excitatory postsynaptic potentials (EPSPs) are depolarizing potentials.
- Inhibitory postsynaptic potentials (IPSPs) are hyperpolarizing potentials.
Neurotransmitters
- Chemical signals that transmit information between neurons or between a neuron and an effector.
- Neurotransmitters can be classified in to several categories based on size and chemical makeup
Summary of Neurotransmitter Removal
- Neurotransmitters can be removed through several mechanisms including diffusion, enzymatic degradation and uptake into cells.
Summation
- Summation of PSPs can result in the firing of an action potential.
- Spatial summation occurs when multiple presynaptic neurons release neurotransmitters at approximately the same time.
- Temporal summation occurs when a single presynaptic neuron releases neurotransmitters in rapid succession.
Neural Circuits
- Simple series: series of neurons
- Diverging: one impulse stimulates many neurons
- Converging: multiple neurons converge on a single neuron
- Reverberating: output neurons stimulate themselves
- Parallel after-discharge: multiple pathways, one final output
Regeneration and Repair of Nervous Tissue
- The nervous system is relatively high in plasticity. This means it can change based on experience and some neurons can regenerate or repair.
- Neurogenesis is little or no repair, especially in the CNS, due to inhibitory influences from neuroglia, growth-stimulating cues that were present during fetal development, and rapid formation of scar tissue
- Damage and repair are possible in the PNS, if cell body is intact, Schwann cells are functional, and scar tissue formation does not occur too rapidly.
Neural Disorders (Multiple Sclerosis & Depression)
- Multiple sclerosis is an autoimmune disease causing progressive destruction of myelin sheath.
- Depression is a neural disorder with various types (major, dysthymia, bipolar, & seasonal). Symptoms include lack of interest, sadness and possibly thoughts of suicide.
Additional Information
- The nervous system is responsible for many functions in the body. The detailed process can be further expanded with more detail.
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Description
Test your knowledge on the fundamental aspects of neuroscience, including neuron types, ion channels, and neuroglia functions. This quiz covers essential concepts that are critical for understanding the nervous system. Perfect for students in a neuroscience or biology course!
