Chapter 7: Nerve Cells & Electrical Signalling Flashcards
Which of the following correctly lists the components of the central nervous system?
brain and spinal cord
Which of the following is located in the autonomic nervous system?
both sympathetic and parasympathetic nervous systems
Which of the following accurately describes afferent neurons?
They transmit information from the periphery to the CNS.
What is the functional unit of the nervous system?
neurons
On what portion of the neuron do action potentials propagate?
axon
Information is transmitted from cell to cell across the chemical synapse via a(n) ________.
neurotransmitter
An action potential originates at the ________ and travels along the axon until it reaches the ________.
axon hillock : axon terminal
What type of ion channels in the membrane of neurons allow ions to move across the membrane at rest and thereby contribute to resting membrane potential?
leak channels
What type of ion channels in the membrane of neurons open or close in response to a neurotransmitter binding to its receptor?
ligand-gated channels
In a neuron, where is the greatest concentration of voltage-gated sodium and voltage-gated potassium channels?
axon hillock
In a neuron, where are voltage-gated calcium channels located?
axon terminal
What is the structural classification of a neuron composed of a single axon and a number of dendritic projections from the nerve cell body?
multipolar
Which of the following is a functional classification of neurons that, for the most part, are bipolar in structure and carry information from the peripheral axon to the central axon?
afferent neurons
Which of the following terms is NOT used to describe a bundle of axons in the central or peripheral nervous system?
ganglia
Which of the following cells is NOT classified as a glial cell?
ventricular cell
What type of cell enhances the velocity of electrical transmission of an action potential along an axon in the central nervous system?
oligodendrocyte
Which of the following best describes the function of the myelin sheath?
reduce a membraneʹs ion permeability
Which of the following is the correct term for the movement of an electrical charge across a membrane?
current
Which of the following determines the resistance to an ionʹs movement across a membrane?
ion channels within the membrane
What is the inverse of resistance?
conductance
Which of the following is NOT a factor involved in the determination of resting membrane potential?
concentration of sodium receptors
Which of the following statements about sodium is FALSE?
At the potassium equilibrium potential, there is an electrical force driving sodium ions out of the cell.
Which of the following best describes the electrochemical forces acting on sodium and potassium ions at the resting membrane potential?
The force on sodium ions is to move into the cell, and the force on potassium ions is to move out of the cell.
Given a cation with an equilibrium potential of -55 mV, if the plasma membrane of the cell is permeable only to this ion, then which of the following best describes the resting membrane potential?
-55 mV