Question | Answer |
two divisions of the nervous system | CNS |
PNS composed of to types of neurons | afferent & efferent |
Afferent neurons | input signals to the CNS (affect what will happen next) |
Efferent neurons | output signals to periphery (effecting change – movement, secrestion, etc.) |
PNS divided into | Somatic and autonomic nervous system |
Somatic nervous system controls | skeletal muscle |
Autonomic nervous system | has two branches; sympathetic and parasympathetic |
Sympathetic controls | emergency branch |
Parasympathetic controls | rest and digest branch |
Dendrites | receive information typically from neurotransmitters |
Dendrites undergo | graded potentials |
Axons undergo | action potentials to deliver information, typically neurotransmitters from xaon terminals |
Which neurons conduct action potentials most rapidly | myelinated neurons |
Myelin sheath is collection of | Schwann cells and oligodendrocytes that are closely associated with the neuron |
Neuronal pathways include | presynaptic, postsynaptic, and interneuronal |
All interneurons are located in the | CNS |
This describes what: Transmit information into the central nervous system from receptors at their peripheral endings | Afferent Neurons |
This describes what: Cell body and the long peripheral process of the axon are in the peripheral nervous stem; only the short central process of the axon eneters the central nervous system | Afferent neurons |
This describes what: Have not dendrites (do not receive inputs from other neurons) | Afferent neurons |
What type of neuron are the Primary Sensory Neurons (DRG) | Afferent neurons |
Spinal and cranial nerve sensory fibers are | afferent neurons |
Sensory receptors don’t have this neural cell component | dendrites |
Sensory receptors are an example of this neuron | afferent neuron |
This describes what: Transmit information out of the central nervous system to effector cells, particularly muscles, glands, or other neurons | Effector neurons |
This describes what: Cell body, dendrites, and a small segment of the axon are in the central nervous system | effector neurons |
This describes what: most of the axon is in the peripheral nervous system | efferent neurons |
This describes what which class of neuron: motor (upper/lower) neurons | efferent neurons |
This describes which class of neurons: spinal/cranial nerves | efferent neurons |
This describes what: Function as integrators and signal changers | interneurons |
This describes what: integrate groups of afferent and efferent neurons into reflex circuits | interneurons |
This describes what: lie entirely within the central nervous system | interneurons |
This describes what: Acount for 99% of all neurons | interneurons |
This describes what: CNS integration pathways (sensory/motor) | interneurons |
The class of neurons respond to afferent pathways | Interneurons |
What deliver information in toe form of neurotransmitters | Presynaptic membranes |
What receives information because they have receptors for neurotransmitters | postsynaptic membranes |
True or False: A singe neuron postsynaptic to one cell can be presynaptic to another cell | True |
Potential difference | difference in electrical charge between two points |
Like charges repulse each other; Unlike charges attracts is known as what | the electrostatic gradient principles |
Membrane potential dexcribes | electrical difference between the fluid inside and outside the cell |
Resting membrane potential has | uneven ion distribution; is cell dependent; “-“ intarcellular/extracellular environment; present in all cells (electrochemical gradient) |
True/False: A large shell of charge difference is needed to establish a membrane potential | False |
Equilibrium Potential of an ion reflects | Transmembrane concentration; no net movement; equal PD forces. |
Establishment of the resting membrane potential is established by which pump | Na+/K+ pump |
The pump uses up to __% of the ATP produced by the cell | 40% |
The intracellular portion is positive or negative | negative |
The extracellular portion is positive or negative | postitive |
Decreasing the ATP increases or decreases the membrane potential | decreases (less negative) |
True/False: The Na+/K+ pump does not require ATP | False |
Each ATP is hydrolyzed to operate the ion pump and allows __ Na+ to __ and __ K+ to __ the cell | 3 Na+ to exit and 2 K+ to enter the cell |
Depolarization occurs when | ion movement reduces the charge imbalance |
Depolarization results in active or passive loss of energy | passive |
Depolarization is a movement in membrane potential toward positive or negative | positive |
Overshoot refers to | the development of a charge reversal |
Repolarizing is movement | back toward the resting potential |
Repolarization is active or passive | active (requires ATP) |
Hyperpolarization is | the development of even more negative charge inside the cell |
Why does hyperpolarization occur | because it takes time to stop repolarizing |
Resting Potential is around __ | -70 mV
Potential = potential difference definition |
Membrane potential = transmembrane potential | the voltage difference between the inside and the outside of a cell |
Equilibrium potential | the voltage difference across a membrane that produces a flux of a given ion species that is equal but opposite to the flux due to the concentration gradient of tha same ion species |
Resting membrane potential = resting potential | the steady transmembrane potential of a cell that is not producing an electric signal |
Graded potential | A potential change of variable amplitude and duration that is conducted decrementally |
What has no threshold or refractory period | Graded potential |
What has a threshold and refractory period | Action potential |
Action potential | a brief all-or-none depolarization of the membrane, reversing polarity in neurons |
Synaptic potential | A graded potential change produced in the postsynaptic neuron in response to the release of a neurotransmitter by a presynaptic terminal |
What potential may be depolarizing or hyperpolarizing | Synaptic potential |
Receptor potential | a graded potential produced at the peripheral ending of afferent neurons (or in separate receptor cells) in response to a stimulus |
Pacemaker potential | a spontaneously occurring graded potential change tha occurs in certain specialized cells |
Threshold potential | membrane potential at which an action potential is initiated |
True/False: Graded potential size is propotianate to the intensity of the stimulus | True |
Can graded potentials be Excitatory, Inhibitory | Both Exitatory or Inhibitory |
Excitatory responses have the action potential more or less likely | more |
Inhibitory responses have the action potential more or less likely | less |
True/False: The size of a graded potential proportional to the size of the stimulus | True
Graded potentials include |
Action or graded potentials have a threshold | Action |
Action or graded potentials have no decremental propagation | Action |
Action or graded potentials exhibit an all or none phenomenon | Action |
Which voltage gate, Na or K opens faster | Na |
Action or Graded potentials decay as they move over a distance | Graded |
Which voltage gate leads to the repolarization after hyperpolarization | K |
True/False: The amplitude of a gnereated action potential is constant in any neuron type | True |
Threshold stimulus allows | inward movement of “+” charges |
Acton potentials require | suprathreshold stimulus; Na influx > K efflux |
True/False: The propagation of the action potential from the dendritic to the axon-terminal end typically one-way | True |
Why is the action potential propagation typically one-way | because the absolute refractory period follows along in the “wake” of the moving action potential |
Saltatorial Conduction | Action potentials jump from one node to the next as they propagate along a myelinated axon |
Why do action potentials move rapidly along myelinated axons | because only the parts of the neuronal membrane that undergo ion movements are the sections at the Nodes of Ranvier. |
Action potentials travel faster in | large myelinated fibers |
What has the amplitude vary with donditions of the initiating event | Graded Potential |
What potential can be summed | Graded Potential |
What potential’s duration varies with initiating conditions | Graded Potential |
What potential can be a depolarization | Graded or Action Potential |
What potential can be a hyperpolarization | Graded Potential |
What potential can be initiated by environmental stimulus, by neurotransmitter, or spontaneously | Graded Potential |
What potential’s mechanism depends on ligand-sensitive channes or other chemical or physical changes | Graded Potential |
What potential cannot be summed | Action Potential |
What potential has a threshold that is usually about 15mV depolarized relative to the resting potential | Action Potential |
What potential has a refractory period | Action Potential |
What potential is conducted without decrement | Action potential |
What potential has the depolarization amplified to a constant value at each point along the membrane | Action potential |
What potential has a duration that is constant for a given cell type under constant conditions | Action potential |
What potential is only a depolarization | Action Potential |
What potential is initiated by a graded potential | Action potential |
What potential depends on voltage-gated channels | Action potential |
Four primary neurons communicate to one secondary neuron is an example of | Convergence |
One primary neuron communicates to four secondary neurons is an example of | Divergence |
__ is the point of communication between two neurons that operate sequentially | the synapse |
Int the axon terminal, the neurotransmitters empty into the | synaptic cleft |
Neurotransmitters bid to the receptors on what after being deposited to the synaptic cleft | postsynaptic cell (typically a dendrite) |
C++ channels are opened by | Action potentials propogated from Na and K voltage-gated channels |
Ca++ influx triggers | neurotransmitter release into the synaptic cleft |
Binding of neurotransmitters to receptor proteins in the postsynaptic membrane is linked to | an alteration in its ion permeability |
An excitatory postsynaptic potential is a graded depolarization that moves the membrane potential | closer to the threshold for firing an action potential |
An inhibitory postsynaptic potential is a graded hyperpolarization that moves the membrane potential | farther from the threshold for firing an action potential |
Threshold refers to | the minimum graded depolarization that initiates the cyclic activity of the voltage-gated Na andK channesl resulting in the initiation of an action potential |
True/False: the membrane potential of a real neuron typically undergoes many EPSPs and IPSPs | True |
True/ False: The membrane can receive both excitatory and inhibitory input from the axon terminals that reach it constantly | True |
Real neurons receive as many as __ terminals | 200,000 |
Motor neurons (UMN/LMN), parasympathetic, and pregangliotic sympathetic neuron terminals all utilize __ as a pre-synaptic neurotransmitter agent | ACH |
True/False: Possible drug effects on synaptic effectiveness includes release and degradation of the neurotransmitter inside the axon terminal | true |
True/False: Possible drug effects on synaptic effectiveness includes released and degradation of the neurotransmitter outside the axon terminal | False |
True/False: Possible drug effects on synaptic effectiveness includes increased neurotransmitter release into the synapse | True
True/False: Possible drug effects on synaptic effectiveness includes prevention of neurotransmitter release into the synapse |
True/False: Possible drug effects on synaptic effectiveness includesinhibition of synthesis of the neurotransmitter | True
True/False: Possible drug effects on synaptic effectiveness includes Increased reuptake of the neurotransmitter from the synapse |
True/False: Possible drug effects on synaptic effectiveness includes decreased reuptake of the neurotransmitter from the synapse | True |
True/False: Possible drug effects on synaptic effectiveness includes increased degradation of the neurotransmitter in the synapse | False |
True/False: Possible drug effects on synaptic effectiveness includes reduced degradation of the neurotransmitter in the synapse | True |
True/False: Possible drug effects on synaptic effectiveness includes reduced biochemical response inside the dendrite | True |
True/False: Possible drug effects on synaptic effectiveness includes increased biochemical response inside the dendrite | False |
Pre/Post/ or general synaptic factor determine synaptic strength: Availability of neurotransmitter | Presynaptic Factor |
Pre/Post/ or general synaptic factor determine synaptic strength: Availabity of precursor molecules | Presynaptic Factor |
Pre/Post/ or general synaptic factor determine synaptic strength: Amound of the rate-limiting enzyme in the pathway for the neurotransmitter synthesis | Presynaptic Factor |
Pre/Post/ or general synaptic factor determine synaptic strength: Axon terminal membrane potential | Presynaptic Factor |
Pre/Post/ or general synaptic factor determine synaptic strength: Axon terminal calcium | Presynaptic Factor |
Pre/Post/ or general synaptic factor determine synaptic strength: Activation of membrane receptors on presynaptic terminal | Presynaptic Factor |
Pre/Post/ or general synaptic factor determine synaptic strength: immediate past history of electrical stat of postsynaptic membrane | Postsynaptic Factors |
Pre/Post/ or general synaptic factor determine synaptic strength: effects of other neurotransmitters or neuromodulators acting on postsynaptic neuron | Postsynaptic Factor |
Pre/Post/ or general synaptic factor determine synaptic strength: Up- or down-regulation and desensitization of receptors | Postsynaptic factors |
Pre/Post/ or general synaptic factor determine synaptic strength: certain drugs and diseases | Postsynaptic factor |
Pre/Post/ or general synaptic factor determine synaptic strength: area of synaptic contact | general factor |
Pre/Post/ or general synaptic factor determine synaptic strength: Enzymatic destruction of neurotransmitter | General factor |
Pre/Post/ or general synaptic factor determine synaptic strength: Geometry of diffusion path | General factor |
Pre/Post/ or general synaptic factor determine synaptic strength: Neurotransmitter reuptake | general factor |
Examination of the laminated organization of neurons and other cells in the cerebral cortex reveals _ layers involved int eh integration of afferent and efferent signals | six |
Name the fuctions of the limbic system | Learning; emotion; appetite (visceral function); sex; endocrine integration |
Afferent neurons go through what part of the nerves | dorsal root ganglion |
Efferent neurons go through what part of the nerves | ventral root |
True/False: many systems receive “dual” innervations (both sypothetic and parasympathetic) | True |
Is the following a location of reception for Acetylcholine or Norepinephrine and epinephrine: Nicotinic Receptors | Acetylcholine |
Is the following a location of reception for Acetylcholine or Norepinephrine and epinephrine: Muscarinic receptors | Acetylcholine |
Is the following a location of reception for Acetylcholine or Norepinephrine and epinephrine: On postganglionic neurons in the autonomic ganglia | Acetylcholine |
Is the following a location of reception for Acetylcholine or Norepinephrine and epinephrine: At neuromuscular junctions of skeletal muscles | Acetylcholine |
Is the following a location of reception for Acetylcholine or Norepinephrine and epinephrine: On some central nervous system neurons | Acetylcholine and norepinephrine and epinephrine |
Is the following a location of reception for Acetylcholine or Norepinephrine and epinephrine: On Smooth muscle | Acetylcholine and norepinephrine and epinephrine |
Is the following a location of reception for Acetylcholine or Norepinephrine and epinephrine: On cardiac muscle | Acetylcholine and norepinephrine and epinephrine |
Is the following a location of reception for Acetylcholine or Norepinephrine and epinephrine: On gland cells | Acetylcholine and norepinephrine and epinephrine |
Is the following a location of reception for Acetylcholine or Norepinephrine and epinephrine: on some neurons of autonomic ganglia | Acetylcholine |
__ depends on neural activity being specifically influenced by particular stimulus | Sensory transduction |
True/False: All sensory receptors are responsive to physical or chemical environmental stimuli | True |
True/False: All sensory receptors are responsive to Transduction of enery into electrical impulses | True |
True/False: All sensory receptors are responsive to located at peripheral nerve ending or as specialized receptor cells | True |
__ occurs when stimuli alter membrane potentials in specialized receptor cells | Sensory transduction |
True/False: Receptor cells of sensory transduction consist of only afferent neurons | False (both afferent neurons and some which communicate with afferent neurons |
Receptor adaptation results in | diminished AP propagation |
A reduction in response (the number of action potentials) in response to the continuous presence of a stimulus is | Receptor Adaptation |
What mechanism helps prevent sensory overload | receptor adaptation |
Activity in a sensory unit is altered by | peripheral events |
The number of action potentials generated by a senory afferent neuron is directly proportional to | stimulus intensity |
If a stimulus occurs in an area of receptive field that has greater density of nerve indings, it is predicted the stimulus will generate a __ number of action potentials | greater |
Overlapping stimulation between neighboring receptive fields provides | general information about the location of a stimulus |
Sesory adaptation represents the __ influences of sensory cortex on primary sensory neuron stimulus sensitivity | negative feedback |
CNS activity can screen out certain types of sensory information by | inhibiting neurons in the afferent pathway |
Neural processing of specific sensory inputs via CNS pathways occurs at | specialized locations in the brain |
What path contains Pain & Temperature conduction, with touch contributions | spinothalamic Tracts |
Non-specific pathways provide background information about | touch and temperature from periphery |
All ascending pathways except those involved in smell, synapse in the __ on their way to the cortex | |
Ascending pathways are subject to | descending controls |
Specific types of mechanosensory stimulation are transduced by | specific types of receptor cells |
A tactile corpuscle that responds to light touch | Meissner’s corpuscle |
A tactile corpuscle that responds to touch | Merkle’s corpuscles |
Merkle receptor cells respond to | touch |
Meissner receptor cells respond to | Light touch |
Free nerve ending respond to | pain |
Lamellated corpuscles that respond to deep pressure | Pacinian corpuscle |
Ruffini corpuscles respond to | warmth |
Pacinian corpuscles repond to | deep pressure. |
CNS processes can reduce pain perception by | altering neural transmission |
True/False: Afferent pain pathways differ from afferent non-pain pathways | True |
Afferent Pain pathways heads up what part of the spinal cord | anterolater column |
Non-pain afferent pathways travel up | dorsal column of spinal cord |
True/False: The Dorsal column system has signals transfer through the brainstem nucleus | True |
True/False: The anterolateral system has signals that transfer through the brainstem nucleus | False |
True/False: The Anterolateral and dorsal afferent pathways both stop in the thalamus of the brain | True |
Fovea cluster is part of what sense | vision (they’re the rods) |
Retinal distrbutuion refers to | cones |
Hair receptors are found on | basilar membrane |
Hair receptors respond to vibratory frequency changes through | endolymph fluids |
Taste is passed along through what chemoreceptors | filliform and folate |
True/False: Graded Potentials do not decay over distance | False |
True/False: Possible drug effects on synaptic effectiveness includes agonsists or antagonists can occupy the receptors | True |