Which of the following is not a function of the nervous system?
sense the internal and external environments
integrate sensory information
direct long-term functions, such as growth
coordinate voluntary and involuntary activities
control peripheral effectors
direct long term functions such as growth
The part of the peripheral nervous system that carries sensory information to the CNS is designated ____.
The efferent division of the peripheral nervous system innervates:
ALL: smooth muscle cells, heart muscle cells, glandular cells, skeletal muscle cells
Which of these is NOT a neuron structural category?
The axoplasm of the axon contains which of the following?
ALL: Mitochondria, neurotubules, vesicles, neurofibrils
Neurons that are rare, small, and lack features that distinguish dendrites from axons are called __>
Neurons in which dendritic and axonal processes are continuous and the soma lies off to one side are called ___.
The largest and most numerous of the glial cells in the central nervous system are the ?
Functions of astrocytes include all of the following except ..
guiding neuron development.
maintaining the blood-brain barrier.
responding to neural tissue damage.
conducting action potentials.
forming a three-dimensional framework for the CNS.
conducting action potential
Which of the following is a type of glial cell found in the peripheral nervous system?
The function of the astrocytes in the CNS include which of the following
ALL: repairing damaged neural tissue, maintain the blood brain barrier, adjusting the composition of the interstitial fluid, guiding neuron development
Small, wandering cells that engulf cells that engulf cell debris and pathogens in the CNS are called___.
The most abundant intracellular cation is ___ while the most abundant extracellular anion is ___.
___ channels open or close in response to physical distortion of the membrane surface.
Any stimulus that opens ___ ion channels will produce a graded potential.
ALL: a sodium, a mechanically gated, a chem gated, a voltage gated
Ions can move across the plasma membrane in which of the following ways?
ALL: through chemically-gated channels as in neuromuscular transmission, by ATP-dependent ion pumps like the sodium-potassium exchange pump, through passive or leak channels, through voltage-gated channels as in the action potential
During propagation of the action potential ____.
ALL: the axon hillock depolarizes the initial segment, local currents depolarize a spot adjacent to the active zone, after threshold is reached sodium channels open rapidly
The all or none principle states that __>
all stimuli great enough to bring the membrane to threshold will produce identical action potentials
Which of the following is true about threshold for an action potential.
It is more positive than the resting potential
Which of the following does not influence the time necessary for a nerve impulse to be transmitted?
whether or not the impulse begins in the CNS
The effect of a nerve impulse on a postsynaptic neuron depends on the ____.
ALL: quality of neurotransmitter released, kind of neurotransmitter released by the presynaptic neuron, characteristics of the receptor on the post synatpic neuron,
Which of the following is not a possible drug effect on synatpic function>
change the type of receptor found in the postsynaptic membrane
Which of the following is a recognized class of opoid neuromodulators?
enkenphalins, endomorphins, dynorphins, enorphins ALL
The neurotransmitter glutamate opens channels that are permeable to sodium ions. What effect does glutamate produce on a postsynaptic neuron?