BIO 669 Understanding Patho Quiz 2 Neurological System Exam 1 with verified solutions

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BIO 699 Understanding Patho Quiz 2 || || || ||




Neurological System: Exam 1 with verified || || || || || ||




solutions

What are the 3 components of the neuron? - Correct answer ✔cell body (soma),
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dendrites, axons ||




where is the cell body (soma) located? - Correct answer ✔mainly in the CNS
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Densely packed cell bodies in the CNS are?
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PNS? - Correct answer ✔nuclei.
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ganglia.



What is located in the cell body (soma)? - Correct answer ✔nucleus and cytoplasm.
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Dendrites are the ________ portion of the neuron. - Correct answer ✔Receptive portion.
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They accept and sense external stimuli. Stimulate incoming signals to cell body.
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Axons transmit impulses where? - Correct answer ✔Transmit impulses AWAY from cell
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body of neuron.
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the long thread like part of a nerve cell along which impulses are conducted from the
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cell body to other cells.
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what is the cone-shaped process where the axon leaves the cell body? - Correct answer
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✔axon hillock ||




As dendrites bring signals to the axon hillock, what occurs? - Correct answer ✔the
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inhibitory and exhibitory graded potentials are summed to determine if an action
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potential can occur to send a signal down the axon hillock.
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What part of the axon has the lowest threshold for stimulation?
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and what occurs here? - Correct answer ✔The initial segment of the axon.
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the action potentials begin at this point.
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Describe membrane polarization during a neuron's resting state. - Correct answer
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✔imbalance of ions is created and maintained by ion pumps.
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The membrane lacks permeability to ions.
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unit of measurement of ion concentration - Correct answer ✔mM (mOsm)
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the separation or ______________ of ions and charges creates _____________. - Correct
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answer ✔polarization; an electrical potential.
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the further distance between the charges = - Correct answer ✔the more polarized .
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Therefore, the closer the distance between the ends results in: - Correct answer
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✔depolarization



The membrane potential refers to the _______________ of the cell. - Correct answer
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✔inside



If the membrane potential is -70 mV, this means: - Correct answer ✔that the inside
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(cytoplasm) is more negative than the extracellular environment.
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The difference in potential is found where on the cell? - Correct answer ✔at the
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membrane. ||




NOT the cell as a whole.
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what ions cause the difference in potential found at the membrane? - Correct answer
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✔mostly Na+, but K+ too. || || || ||




Which way would K+ move if left to diffusion and the membrane where permeable?
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Na+? - Correct answer ✔Move from high to low concentration. So K+ would move to
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ECF and Na+ to the ICF.
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If there is 150mM Na+ and 5mM K+ outside the cell and 15mM Na+ and 150mM K+
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inside, why would they not diffuse equally fast across the membrane? - Correct answer
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✔If fully permeable, many more Na+ would move into the cell than K+ out d/t negative
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charge and lower concentration of Na+ inside the cell.
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Na+ has an electrical and chemical gradient that is driving Na+ into the ICF.
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The positive Na+ will be highly attracted to the negative ICF. Additional force to pull
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Na+ in and retain K+.
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what is used to describe the forces affecting ion movement if allowed to become
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permeable to a membrane? - Correct answer ✔electrochemical gradient.
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Chemical gradients move from __________ concentration to __________.
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This makes them become: - Correct answer ✔high concentration to low conentration.
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becomes more random -- lower energy state.
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How to electrical gradients operate? - Correct answer ✔opposite charges attract, similar
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charges repel. || ||




This can set up a force to move charged particles.
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Potentials are charges that are separated by:
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They are measured in: - Correct answer ✔a membrane.
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volts or millivolts (mV)
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Resting membrane potential is the result of: - Correct answer ✔retained proteins within
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the cell and ions (mostly Na+ and K+) creating electrochemical gradients.
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This results in a relatively negative charge within the inner aspect of the plasma
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membrane.