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A&P HW CH 12
A&P HW CH12
Question | Answer |
---|---|
Under what classification does multipolar, bipolar, and unipolar neurons go under? | Structural classification |
Under what classification does sensory, motor, interneuron, afferent, efferent, and association neuron go under? | Functional classification |
List the structures in which an electrical impulse would travel beginning with the post-synaptic membrane. | Dendrites, soma, axon hillock, internode, node of ranvier, terminal aborization, and synaptic knobs |
T / F ? Graded potentials can result from voltage across the plasma membrane | True |
T / F ? Graded potentials can result from mechanical stimulation or temperature changes. | True |
T / F ? The potential change can vary from small to large depending on the stimulus strength or summation | True |
T / F ? The effects produced by one graded potential can be added onto the effects of another graded potential | True |
T / F ? Increased permeability of the membrane to sodium results in depolarization. | True |
T / F ? A depolarizing graded potential can cause an action potential. | True |
Classify what goes under excitatory neurotransmitter actions | - Binds to a chemically gated sodium channel - Sodium moves down concentration gradient into the neuron - The inside of neuron becomes more positive |
Classify what goes under inhibitory neurotransmitter actions | - Binds to a chemically gated potassium channel - Binds to a chemically gated chloride channel - Potassium moves down its concentration gradient out of neuron - Chloride moves down its concentration gradient into the neuron |
What is the order for EPSP from beginning to end? | - Excitatory neurotransmitter released from presynaptic neuron - Neurotransmitter binds to chemically gated sodium channels - Sodium channels open; Sodium flows into neuron - Inside of neuron becomes more positive - EPSP propagates toward axon hillock |
What is the order of IPSP from beginning to end? | - An inhibitory neurotransmitter binds to chemically gated K+ channels - K+ channels open - K + flows out of neuron - Inside of neuron becomes more negative - IPSP propagates toward axon hillock |
What glial cell forms the myelin sheath in the CNS? | Oligodendrocytes |
What glial cell has the function in the production and circulation of CSF? | Ependymal cells |
What glial cells has macrophages of the CNS? | Microglia |
What is the msot abundant CNS glial cells? | Astrocytes |
What glial cell is involved with neurogenesis, scar formation, and BBB maintenance? | Astrocytes |
What glial cell forms the myelin sheath in the PNS? | Neurolemmocytes |
What is the name of the PNS cells that surround and insulate the somas? | Satellite cells |
What are the components of the peripheral nerve in a sequence from outside to inside? | Epineurium --> Nerve --> Pernieurium --> Fascicles --> Endoneurium --> Neurolemmocytes --> Axolemma |
Classify the given items into what classification: - Based upon the CNS component nerve arises from; would include spinal nerves | Structural classification |
Classify the given items into what classification: - based upon direction information is sent; would include sensory, motor, and mixed nerves. | Functional Classification |
Where are phosphate, negatively charged proteins, and potassium more abundant? Cytosol or ISF? | Cytosol |
Where are sodium and chloride more abundant? Cytosol or ISF? | ISF |
Relative Refractory Period | Occurs when voltage-gated sodium channels have returned to resting state; Ensures that the action potential moves down the axon in only one direction; neuron is hyperpolarized |
Absolute Refractive Period | Occurs 1ms after an action potential; no amount of stimulus will initiate a second action potential; Voltage-gated sodium channels are opened then closed in the inactivated state |
If neurotransmitter from Neuron A causes Neuron B to hyperpolarize, this is an example of what? | Inhibitory postsynatpic potential |
The most common type of neuron contains many dendrites and a single axon. Structurally, this is classified as a(n) | Multipolar neuron |
Scorpion agitoxin is a neurotoxin that blocks the activity of voltage-gated potassium channels. In the presence of agitoxin, which will occur during an action potential? | The neuron will remain depolarized and unable to repolarize. |
Nerve growth factors that stimulate outgrowth of severed axons are secreted by | neurolemmocytes. |
Which part of a neuron contains calcium pumps and channels? | Synaptic bulbs |
The ___________ nervous system transmits information from receptors to the CNS, while the ___________ nervous system transmits information from the CNS to the rest of the body. | sensory; motor |
A typical synapse in the CNS consists of a presynaptic neuron and a postsynaptic neuron, separated by a narrow space called the | synaptic cleft. |
Myelin sheaths mainly consist of which part of the glial cells that form them? | plasma membranes |
What type of cells produce the myelin sheath in the central nervous system (CNS)? | Oligodendrocytes |
When threshold is reached, depolarization occurs with the same amplitude of potential change. This is known as | the All-or-None principle. |
The _______ is a period of time when a membrane cannot respond to another stimulus (no matter how strong). | absolute refractory period |
What is the correct order for the events of neurotransmitter release from the synaptic terminal AFTER the action potential reaches the axon terminal and voltage-gated Ca2+ channels open? | Action potential reaches axon terminal,Ca2+ channels open, Ca2+ enters terminal and binds to sensor protein in the cytoplasm,Ca2+-protein complex stimulates fusion of the docked synaptic vesicle with the membrane, transmitter into synaptic cell |
The fundamental physiological properties that enable nerve cells to communicate with other cells are | ability to respond to environmental changes, produce electrical signals that are quickly conducted to other cells at distant locations, and to secrete a chemical that will stimulate the next cell when an electrical signal reaches the end of an axon |
Pain receptors in the skin send signals to the CNS for processing. These pain receptors are an example of ____________ neurons. | afferent |
Neurons that carry signals from the CNS to skeletal muscle for contraction would be classified as _____________ neurons. | efferent |
The vagus nerve contains afferent and efferent neurons, therefore it is an example of a(n) __________ nerve. | mixed |
If all the sodium leakage channels were removed from the cell membrane of a neuron, | the membrane potential would be about -90 millivolts. |
When sodium enters the neuron via chemically gated sodium channels, the membrane will depolarize. Therefore, the membrane potential will become more | positive |
When sodium enters the neuron via chemically gated sodium channels, the membrane will depolarize. Therefore, the membrane potential will become more | positive. |
On a graph of an action potential, the small depolarizations that lead to threshold are from | excitatory postsynaptic potentials (EPSPs). |
EPSP Result | the sodium channels open and sodium ions pour into the intracellular fluid. |
T/F ? The inflow of sodium ions into the intracellular fluid causes depolarization of the neuron's inner cell membrane. | True |
An inhibitory post synaptic potential (IPSP) will do what? | will make the membrane potential of a neuron's inner cell membrane more negative. |
An inhibitory post synaptic potential (IPSP) | will make the membrane potential of a neuron's inner cell membrane more negative. |
An excitatory post synaptic potential (EPSP) | will make the membrane potential of a neuron's inner cell membrane more positive. |
An EPSP will cause | both sodium and potassium gates to open, allowing sodium to diffuse into the cell and potassium to diffuse out of the cell. |
Depolarization of a cell membrane occurs because | more sodium ions diffuse into the cell than potassium ions diffuse out of it. |
Depolarization is initiated by a stimulus that makes the membrane potential | more positive. |
T/F ? The inside of the cell membrane becomes negative at the time of an action potential. | False |
A recently depolarized area of a cell membrane cannot generate an action potential because of the | absolute refractory period. |
T/F ? On a typical neuron, the axon is usually longer in length than the dendrites. | True |
T/F? The endoneurium wraps around groups of fasicles to form a nerve. | False |
T/F ? In neurons, protein pumps allow substances to move passively down their concentration gradients. | False |
T/F ? Sodium has a higher concentration outside the cell than within. | True |
T/F ? Greater current flow is possible with larger resistance and a lower voltage. | False |
T/F ? The leakage of potassium plays a more significant role in the resting membrane potential than the leakage of sodium. | True |
T/F? Postsynaptic neurons can generate both inhibitory and excitatory postsynaptic potentials simultaneously. | True |