Which of the following is true about the movement of ions across excitable living membranes?
A) Ions always move actively across membranes through leakage channels.
B) Some ions are prevented from moving down their concentration gradients by ATP-driven pumps.
C) Sodium gates in the membrane can open in response to electrical potential changes.
D) The bulk of the solutions inside a cell are negatively charged.
Answer: B) Some ions are prevented from moving down their concentration gradients by ATP-driven pumps.
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Fundamental of the Nervous System and Nervous Tissue
- Select the correct statement about serial processing.
- Neurons may be classified according to several characteristics. Which of the following is correct?
- If a motor neuron in the body were stimulated by an electrode placed about midpoint along the length of the axon ________.
- In what way does the interior surface of a cell membrane of a resting (nonconducting) neuron differ from the external environment? The interior is ________.
- A second nerve impulse cannot be generated until ________.
- ________ is an indolamine.
- All of the following are true of graded potentials except that they ________.
- When a sensory neuron is excited by some form of energy, the resulting graded potential is called a(n) ________.
- Which of the following will occur when an excitatory postsynaptic potential (EPSP) is being generated on the dendritic membrane?
- An inhibitory postsynaptic potential (IPSP) is associated with ________.
- Nerve cell adhesion molecules (N-CAMs) ________.
- Immediately after an action potential has peaked, which cellular gates open?
- Schwann cells are functionally similar to ________.
- Neuroglia that control the chemical environment around neurons by buffering potassium and recapturing neurotransmitters are ________.
- Ependymal cells ________.
- The sympathetic and parasympathetic are subdivisions of the ________.
- Which group of fibers spreads impulses at up to 1 meter per second?
- Which of the following is a good example of a neuromodulator?
- Select the correct statement about synapses.
- An action potential ________.
- The sodium-potassium pump ________.
- Choose the statement that is most correct about membrane potential.
- The part of the neuron that normally receives stimuli is called ________.
- Which of these ions is actively transported through the cell membrane to establish a resting potential?