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153 Cards in this Set
- Front
- Back
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What is the most common type of neuron in the central nervous system? |
Multipolar Neurons |
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What is another word for soma? |
Cell Body |
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What contains a large, round nucleus with prominent nucleolus? |
The cell body or soma |
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The root word "soma" means |
Body |
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*** What is the cytoplasm surrounding the nucleus called? |
Perikaryon |
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What does the root word "peri" mean? |
Around
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What does the root word "Karyon" mean? |
Nucleus |
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What does the perikaryon contain that is similar to the intermediate filaments and microtubules of other types of cells? |
Neurofilaments, Neurotubules |
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What are the microfilaments in the cytoplasm of a neuron called? |
Neurofilaments |
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What does the root word "neuro" mean? |
Nerve |
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Filament is derived from the latin word "filum" meaning: |
Thread |
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What are microtubules in the cytoplasm of a neuron called? |
Neurotubules |
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The word "tubules" refers to what? |
Tubes |
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What are bundles of neurofilaments or microfibrils in the cytoplasm of a neuron called? |
Neurofibrils |
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What extends into the dendrites and axon, providing internal support for them? |
Bundles of neurofilaments or neurofibrils |
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What do the perikaryon contain that provides energy and synthesize organic materials, especially the chemical neurotransmitters that are important in cell-to-cell communication? |
organelles |
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What gives perikaryon it's coarse, grainy appearance? |
-Mitochondria -Free and fixed ribosomes -Rough endoplasmic reticulum (RER) |
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What do mitochondria generate to meet the high energy demands of an active neuron? |
ATP |
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What do the ribosomes and RER synthesize in neurons? |
Proteins |
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What German microscopist are Nissl bodies named after? |
Franz Nissl |
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What are clusters of RER and free ribosomes that stain darkly called? |
Nissl bodies |
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What is another name for nissl bodies? |
Grey Matter |
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What do most neurons lack that are important organelles that help to organize the cytoskeleton and the microtubules that move chromosomes during mitosis? |
Centrioles |
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Due to the lack of centrioles in neurons what is it that typical CNS neurons can't do? |
Divide |
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Because CNS cannot divide they cannot: |
be replaced if lost to injury or disease |
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What persist in the adult nervous system, but are typically inactive except in the nose? |
Neural Stem cells |
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What is regenerated in the nose that maintains our sense of smell? |
Olfactory (smell) receptors |
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What active neural stem cells persist in the adult nervous system and are a part of the brain that is involved in storing memories? |
The hippocampus |
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What are researchers investigating that may help in preventing or reversing neuron loss due to trauma, disease, or aging? |
The control mechanisms that trigger neural stem cell activity |
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What has a variable number of slender, and has sensitive processes (extensions) that extend out from the cell body? |
Dendrites |
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What do dendrites play a key role in? |
Intercellular communication |
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What are the fine .5-1um long studded processes on highly branched dendrites called? |
Dendritic spines |
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In the CNS what primarily happens at the dendritic spines? |
a neuron receives information from other neurons |
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*** What percent of the neuron's total surface area do dendritic spines make up? |
80-90 percent |
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What is a long cytoplasmic process capable of propagating an electrical impulse known as an action potential called? |
An axon |
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What is the cytoplasm of the axon called? |
Axoplasm |
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What does the axoplasm contain? |
Neurofibrils, Neurotubule, Small vesicles, Lysosomes, Mitochondria, and various enzymes |
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What specialized portion of the plasma membrane surrounds the axoplasm? |
Axolemma |
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In the CNS, the axolemma may be _______ to the interstitial fluid or, it may be _______ by the cellular processes of _________. |
Exposed, Covered, Neuroglia |
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What is another name for the base of the axon in a multipolar neuron? |
Initial Segment |
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What thickened region joins the initial segment of the axon and the cell body? |
Axon Hillock |
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When an axon produces a side branch, what is it called? |
collaterals |
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What enable a single neuron to communicate with several other cells? |
collaterals |
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What are the axon trunk and any collaterals that end in a series of fine extensions called? |
Telodendria |
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What is another word for telodendria? |
Terminal branches |
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Where do the telodendria end at? |
Axon terminal |
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The axon terminals play a role in: |
Communication with another cell |
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What are other names for the axon terminals? |
synaptic terminals, synaptic knobs, and synaptic boutons |
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What are each axon terminal a part of? |
Synapse |
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What is a specialized site where the neuron communicates with another cell? |
Synapse |
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What two cells are involves in synapse? |
-presynaptic cell -postsynaptic cell |
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Which cell in the synapse sends a message and includes the axon terminal? |
Presynaptic cell |
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Which cell in the synapse receives the message? |
Postsynaptic cell |
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What narrow space separates the two cells of synapse? |
Synaptic cleft |
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What is a chemical compound released by one neuron to affect the membrane potential of another? |
Neurotransmitter |
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In the communication between the two synapse cells, the axon terminal of the ___________ ____ most commonly release chemicals called _________________ into the ________ _____. |
-presynaptic cell -neurotransmitters -synaptic cleft |
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What are neurotransmitters contained in? |
Synaptic Vesicles |
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What electrical event triggers the release of neurotransmitters? |
the arrival of an action potential. |
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What cell activity is affected when neurotransmitters are released and flood the synaptic cleft? |
Postsynaptic cell |
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A presynaptic cell is usually a |
Neuron |
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The postsynaptic cell can be |
neuron, or another type of cell |
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Where can one neuron communicate with another neuron? |
-At a synapse on a dendrite -On the cell body -Along the length of the axon of the receiving cell |
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Where does the synapse between a neuron and a muscle cell happen? |
Neuromuscular junction |
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Where do neurons control or regulate the activity of a secretory (gland) cell? |
Neuroglandular junction |
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Neurons also _________ a variety of other cell types, such as __________. |
Innervate, Adipocytes |
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What does innervate mean? |
To supply |
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What type of cells are adipocytes? |
Fat cells |
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The structure of the axon terminal can vary with what type of cell? |
Postsynaptic cell |
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What is relatively simple and occurs where the postsynaptic cell is another neuron? |
round axon terminal |
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What separates the presynaptic membrane from the postsynaptic membrane? |
Synaptic cleft |
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Where are the neurotransmitters release from during a synapse? |
The presynaptic membrane |
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Where are the receptors for the neurotransmitters that come from the presynaptic membrane during synapse found? |
The postsynaptic membrane |
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Each axon contains mitochondria and thousands of what filled with neurotransmitter molecules? |
Vesicles |
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What is responsible for reabsorbing breakdown products of neurotransmitters that are formed at the synapse and then reassemble them? |
Axon terminal |
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What does the axon continuously supply in the cell body, along with enzymes and lysosomes? |
Synthesized neurotransmitters |
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What proteins known as "molecular motors" pull materials through the length of the axon on neurotubules? |
Kinesin and dynein |
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What do kinesin and dynein run off of? |
ATP |
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What is the movement of materials between the cell body and axon terminals called? |
axoplasmic transport |
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When materials travel slowly, at rates of a few millimeters per day, they are known as a mechanism called what? |
Slow Stream |
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Vesicles containing neurotransmitters move much more rapidly, at 5-10 MM per hour are known as? |
Fast Stream |
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In what direction can axoplasmic transport move in? |
Both directions |
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Kinesin carries materials from the cell body to the axon terminal, what is this movement called? |
Anterograde Flow |
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What does the root word "antero" mean? |
forward |
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Dynein carries other substances from the axon terminal toward the cell body, what is this movement called? |
Retrograde flow |
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What does the root word "retro" mean? |
backward |
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What does retrograde flow deliver to the cell body, where this substance is then altered by turning certain genes on or off? |
Debris or unusual chemicals |
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What are the classifications of Neurons? |
Anaxonic, Bipolar, Unipolar, Multipolar |
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Which neurons are small and have numerous dendrites, but no axon? |
Anaxonic neurons |
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Where are anaxonic neurons located? |
In the brain and in special sense organs |
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Which neurons functions are poorly understood? |
Anaxonic neurons |
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Which neurons have two distinct processes - one dendrites that branches extensively into dendritic branches at its distal tip, and one axon - with the cell body between the two. |
Bipolar Neurons |
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Where is the cell body found in the Bipolar neurons? |
Between the axon and the dendrite |
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What does the dendrite in the Bipolar neuron branch extensively into? |
Dendritic branches at its distal tip |
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Which neuron classification is rare? |
Bipolar neurons |
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What organs do Bipolar neurons occur in? |
special sense organs |
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What do Bipolar neurons relay in specialized organs? |
information about sight, smell, or hearing |
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Where do Bipolar neurons relay information about sight, smell, or organs from? |
Receptor cells to other neurons |
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What is another word for unipolar neuron? |
Pseudounipolar neuron |
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Which neuron has a dendrite and axon that are continuous - basically, fused - and the cell body lies off to the one side? |
Unipolar neuron |
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Where is the cell body found on a unipolar neuron? |
Off to the side |
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Where is the initial segment in a unipolar neuron found? |
Where the dendrites converge |
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What is found where the dendrites converge in a unipolar neuron? |
The initial segment |
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What are most sensory neurons in the peripheral nervous system called? |
Unipolar neuron |
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Where do the longest unipolar neurons carry the sensations from and to? |
From the tips of the toes to the spinal cord |
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Which classification of neurons have two or more dendrites and a single axon? |
Multipolar neurons |
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Where are multipolar neurons most common? |
(CNS) Central nervous system |
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What are all neurons that control skeletal muscles called? |
Multipolar neurons |
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Where does the longest mulipolar neuron carry motor commands from and to? |
From the spinal cord to small muscles that move the toes |
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What are the 3 functions of neurons? |
Sensory neurons, Motor Neurons, Interneurons |
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What is another word for sensory neurons? |
Afferent neurons |
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Where do sensory receptors deliver information to? |
(CNS) Central nervous system |
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Where are the cell bodies of sensory neurons located? |
Peripheral sensory ganglia |
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What is a collection of neuron cell bodies in the PNS called? |
Ganglion |
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What classification of neuron is a sensory neuron? |
Unipolar neuron |
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What is an axon that carried sensory information to the central nervous system called?` |
Afferent fiber |
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What do the afferent fibers extend between? |
A sensory receptor and the CNS |
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What monitors the outside world and our position within it? |
Somatic sensory neurons |
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What monitors internal conditions and the status of other organ systems? |
Visceral sensory neurons |
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What are the three groups of sensory receptors? |
Interoceptors, Exteroceptors, Proprioceptors |
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What does the root word "intero" mean? |
Inside |
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What does the root word "extero" mean? |
outside |
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Which sensory receptor monitors the digestive, respiratory, cardiovascular, urinary, and reproductive systems, and provide sensations of distension (stretch), deep pressure, and pain? |
Interoceptors |
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Which sensory receptor provides information about the external environment in the form of touch, temperature, or pressure sensations, and the more complex senses of taste, smell, sight, equilibrium (balance), and hearing? |
Exteroceptors |
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Which sensory receptor monitors the position and movement of skeletal muscles and joints? |
Proprioceptors |
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What is another word for motor neurons? |
efferent neurons |
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What do motor neurons carry? |
Instructions |
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Where do motor neurons carry instructions from? |
(CNS) Central nervous system |
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Where do motor neurons carry instructions to? |
Peripheral effectors in a peripheral tissue, organ, or organ system |
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What are axons traveling away from the CNS called? |
efferent fibers |
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What are the two major efferent system called? |
(SNS) somatic nervous system, (ANS) autonomic nervous system |
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What includes all the somatic motor neurons that innervate skeletal muscles? |
(SNS) somatic nervous system |
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Is your control over the SNS conscious or unconscious? |
Conscious |
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Where is the cell body of a somatic motor neuron? |
In the CNS |
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Where does the axon of a somatic motor neuron extend into? |
The periphery within a peripheral nerve |
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What does the axon extension of a somatic motor neuron do in the peripheral nerve? |
Innervate skeletal muscle fibers at neuromuscular juntion. |
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Where does the peripheral nerve innervate the skeletal muscle fibers? |
At the neuromuscular juction |
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Do you have conscious control over Visceral motor neurons? |
No |
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What innervate all peripheral effectors other than skeletal muscles? |
Visceral motor neurons |
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What do visceral motor neurons innervate (supply)? |
Smooth muscle, Cardiac muscle, Glands, Adipose Tissue |
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What part of the visceral motor neuron is found in the CNS? |
Axon |
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What does the axon of the visceral motor neuron in the CNS innervate (supply)? |
a second set of visceral motor neurons in peripheral autonomic ganglia |
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What do cell bodies located in the autonomic ganglia innervate and control? |
Peripheral effectors |
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To get from the CNS to a visceral effector such as smooth muscle cell, a ______ must travel along one ____, be relayed across a _______, and then travel along a second ____ to its final destination. |
Signal, axon, synapse, axon |
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What are the axons extending from the CNS to an autonomic ganglion called? |
Preganglionic fibers |
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What are axons connecting the ganglion cells with peripheral effectors called? |
Postganglionic fibers |
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What is located between sensory and motor neurons? |
Interneurons |
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What is another word for interneurons? |
association neurons |
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What functional neuron outnumber all other types of neurons combined? |
Interneurons |
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Where are interneurons located? |
Brain, Spinal cord, autonomic ganglia |
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What do interneurons distribute? |
Sensory information |
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What do interneurons coordinate? |
Motor activity |
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What determines the amount of interneurons involved in a response to a given stimulus? |
Complexity |
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What higher functions do interneurons play a part in? |
Memory, Planning, Learning |
