Podcast
Questions and Answers
Which of the following is NOT a primary function of the nervous system?
Which of the following is NOT a primary function of the nervous system?
Nerve impulses are also known as action potentials.
Nerve impulses are also known as action potentials.
True (A)
What two broad categories are introduced in the overview of nervous tissue?
What two broad categories are introduced in the overview of nervous tissue?
Neurons and Neuroglia
The nervous system detects changes through ______ receptors.
The nervous system detects changes through ______ receptors.
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Which term best describes the nervous system's ability to analyze incoming sensory information and make decisions?
Which term best describes the nervous system's ability to analyze incoming sensory information and make decisions?
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Match the function of the nervous system with the corresponding description.
Match the function of the nervous system with the corresponding description.
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Neurons are not electrically excitable cells.
Neurons are not electrically excitable cells.
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What is the primary role of the nervous system in maintaining homeostasis?
What is the primary role of the nervous system in maintaining homeostasis?
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What type of communication do action potentials facilitate?
What type of communication do action potentials facilitate?
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Graded potentials are capable of long distance communication.
Graded potentials are capable of long distance communication.
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What two factors determine the production of an action potential or a graded potential?
What two factors determine the production of an action potential or a graded potential?
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Leak channels alternate between ______ and closed.
Leak channels alternate between ______ and closed.
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Which type of ion channel responds to chemical stimuli?
Which type of ion channel responds to chemical stimuli?
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Which type of ion channel responds to changes in membrane potential?
Which type of ion channel responds to changes in membrane potential?
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Match the type of ion channel with its primary stimulus:
Match the type of ion channel with its primary stimulus:
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Where are leak channels found?
Where are leak channels found?
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Which of the following is NOT a factor contributing to the resting membrane potential of a neuron?
Which of the following is NOT a factor contributing to the resting membrane potential of a neuron?
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The inside of a non-conducting neuron's membrane is positively charged relative to the outside.
The inside of a non-conducting neuron's membrane is positively charged relative to the outside.
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What type of gated channel opens in response to a chemical stimulus?
What type of gated channel opens in response to a chemical stimulus?
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A graded potential occurs in response to the opening of a mechanically-gated or _________ ion channel.
A graded potential occurs in response to the opening of a mechanically-gated or _________ ion channel.
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Match the type of gated channel with its stimulus:
Match the type of gated channel with its stimulus:
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Where are voltage-gated channels primarily located on a neuron?
Where are voltage-gated channels primarily located on a neuron?
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Most anions can leave the cell freely, contributing to the resting membrane potential.
Most anions can leave the cell freely, contributing to the resting membrane potential.
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What are small deviations in the resting membrane potential called?
What are small deviations in the resting membrane potential called?
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The amplitude of a graded potential is dependent on what factor?
The amplitude of a graded potential is dependent on what factor?
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Graded potentials can be summed together to increase their amplitude.
Graded potentials can be summed together to increase their amplitude.
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What are the two main phases of an action potential?
What are the two main phases of an action potential?
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Action potentials occur only with the membrane potential reaches ______.
Action potentials occur only with the membrane potential reaches ______.
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Match the type of channel with the corresponding potential they use:
Match the type of channel with the corresponding potential they use:
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In what location do action potentials primarily originate?
In what location do action potentials primarily originate?
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Graded potentials propagate over long distances.
Graded potentials propagate over long distances.
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What type of communication is facilitated by action potentials?
What type of communication is facilitated by action potentials?
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What is the term for the combined effect of neurotransmitter release from several presynaptic end bulbs leading to a nerve impulse?
What is the term for the combined effect of neurotransmitter release from several presynaptic end bulbs leading to a nerve impulse?
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Spatial summation occurs when neurotransmitters are released at different times at a single synapse.
Spatial summation occurs when neurotransmitters are released at different times at a single synapse.
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Name one small molecule neurotransmitter.
Name one small molecule neurotransmitter.
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Neuropeptides such as enkephalins inhibit pain impulses by suppressing the release of substance ________.
Neuropeptides such as enkephalins inhibit pain impulses by suppressing the release of substance ________.
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Match the neurotransmitter or neuropeptide with its primary function:
Match the neurotransmitter or neuropeptide with its primary function:
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Which of the following is NOT a neuropeptide?
Which of the following is NOT a neuropeptide?
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Temporal summation refers to the effect of multiple neurotransmitters released simultaneously at different synapses.
Temporal summation refers to the effect of multiple neurotransmitters released simultaneously at different synapses.
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Name one neuropeptide that may be related to controlling pain and registering emotions.
Name one neuropeptide that may be related to controlling pain and registering emotions.
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Which neuropeptide is known for stimulating thirst and potentially regulating blood pressure in the brain?
Which neuropeptide is known for stimulating thirst and potentially regulating blood pressure in the brain?
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Reverberating circuits are a type of neural circuit designed to amplify signals through a single pathway.
Reverberating circuits are a type of neural circuit designed to amplify signals through a single pathway.
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What is the general term for the capability of the nervous system to change based on experience?
What is the general term for the capability of the nervous system to change based on experience?
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The neuropeptide that is found both in the brain and the small intestine, and may regulate feeding as a 'stop eating' signal is called __________.
The neuropeptide that is found both in the brain and the small intestine, and may regulate feeding as a 'stop eating' signal is called __________.
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Match each type of neural circuit with its description:
Match each type of neural circuit with its description:
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According to the text provided, what is one cause for limited regeneration in the central nervous system?
According to the text provided, what is one cause for limited regeneration in the central nervous system?
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Angiotensin II only works as a neuropeptide in the brain and does not have roles elsewhere in the body
Angiotensin II only works as a neuropeptide in the brain and does not have roles elsewhere in the body
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Which neuropeptide plays a role in both food intake stimulation and in stress response?
Which neuropeptide plays a role in both food intake stimulation and in stress response?
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Study Notes
Nervous Tissue Overview
- Nervous tissue helps maintain homeostasis by controlling conditions within healthy limits.
- The nervous system has various branches.
- Nervous tissue contains different cell types.
Nervous System Overview
- Sensory neurons carry information toward the CNS (Central Nervous System).
- Interneurons, within the brain or spinal cord, process information.
- Motor neurons carry signals away from the CNS to muscles or glands.
Nervous System Layout
- The CNS includes the brain and spinal cord.
- The PNS (Peripheral Nervous System) consists of cranial nerves, spinal nerves, enteric plexuses, and sensory receptors.
Organization of the Nervous System
- The sensory division receives information and sends it to the CNS.
- The motor division transmits information from the CNS to effectors (muscles or glands).
- The somatic nervous system regulates skeletal muscle activity.
- The autonomic nervous system controls smooth muscles, cardiac muscles, and glands.
Functions of the Nervous System
- Sensory function detects changes through sensory receptors.
- Integrative function analyzes incoming sensory data, stores it, and makes decisions.
- Motor function elicits responses to stimuli via effectors.
Histology of Nervous Tissue
- Neurons are electrically excitable cells.
- Nerve impulses (action potentials) are how the nerve signal travels.
Neurons (Components)
- Dendrites receive signals from other neurons.
- The cell body contains the nucleus and other organelles.
- The axon transmits the signal away from the cell body.
Neuronal Classification (Structural)
- Multipolar neurons have multiple processes extending from the cell body.
- Bipolar neurons have two processes extending from the cell body.
- Unipolar (pseudounipolar) neurons have a single process that divides into two branches.
Neuronal Classification (Functional)
- Sensory neurons carry information toward the CNS.
- Motor neurons transmit signals from the CNS to muscles or glands.
- Interneurons connect sensory and motor neurons.
Neuroglia
- Neuroglia support neurons, make up about half of the nervous system volume, and can multiply.
- In the CNS, there are four types of neuroglia (astrocytes, oligodendrocytes, microglia, ependymal cells).
- In the PNS, there are two types of neuroglia (satellite cells, Schwann cells).
Myelin of Neurons
- The myelin sheath, produced by Schwann cells (PNS) or oligodendrocytes (CNS), insulates axons and increases signal speed.
Gray Matter vs. White Matter
- Gray matter contains neuron cell bodies, dendrites, and unmyelinated axons.
- White matter consists mainly of myelinated axons.
Electrical Signals in Neurons
- Excitable cells communicate via action potentials or graded potentials.
- Action potentials are used for long-distance signaling.
- Graded potentials are used for short-distance signaling.
Resting Membrane Potential
- The neuron's membrane is negatively charged inside and positively charged outside.
- This difference is due to unequal ion distribution and selective membrane permeability.
Graded Potentials
- Graded potentials are small changes in membrane potential that vary in strength and duration depending on the stimulus.
Action Potentials
- Action potentials are rapid, large changes in membrane potential that are all-or-none phenomena.
Propagation of Action Potentials
- Action potentials propagate along the axon without losing strength.
- Continuous conduction occurs in unmyelinated axons.
- Saltatory conduction occurs in myelinated axons, skipping over segments of the axon, increasing speed.
Factors Affecting Propagation Speed
- Axon diameter—larger axons transmit signals faster.
- Myelination—myelin increases signal speed.
- Temperature—higher temperatures increase signal speed.
Signal Transmission at Synapses
- Synapses are junctions between neurons or neurons and effectors.
- Electrical synapses are characterized by gap junctions and rapid signal transmission.
- Chemical synapses rely on neurotransmitters for signal transmission.
Events at the Synapse
- Neurotransmitters are released by the presynaptic neuron.
- They bind to receptors on the postsynaptic neuron, causing a change in membrane potential.
- Neurotransmitters are removed from the synaptic cleft by diffusion, enzymatic degradation, or reuptake.
Summation
- Summation is the process of adding together multiple graded potentials, either spatially (from different sources) or temporally (from the same source over time).
- Summation determines whether an action potential is initiated.
Neurotransmitters
- Small molecule neurotransmitters (e.g., acetylcholine, amino acids, biogenic amines).
- Neuropeptides (e.g., substance P, endorphins).
- Some neurotransmitters excite (depolarize); others inhibit (hyperpolarize) postsynaptic neurons.
Postsynaptic Potentials
- Excitatory postsynaptic potentials (EPSPs) are depolarizing potentials.
- Inhibitory postsynaptic potentials (IPSPs) are hyperpolarizing potentials.
Structure of Neurotransmitter Receptors
- Ionotropic receptors contain a binding site and an ion channel.
- Metabotropic receptors contain a binding site coupled to a G protein, which affects other channels.
Damage and Repair of Nervous Tissue
- The CNS has limited regenerative abilities, often resulting in permanent damage from injury.
- The PNS may show regrowth or repair if the cell body is intact.
- CNS damage is often followed by scar tissue formation and limited regeneration.
Neural Disorders
- Multiple sclerosis is an autoimmune disease damaging the myelin sheath.
- Depression is a complex disorder with various types and potential causes.
- Other disorders may arise from dysfunction in various processes.
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Description
Test your knowledge on the primary functions and mechanisms of the nervous system with this quiz. Explore topics including nerve impulses, receptors, and ion channels. Perfect for students studying biology at any level.
