How can we help?

You can also find more resources in our Help Center.

65 terms

Anatomy Exam 3- Chapter 12

STUDY
PLAY
Which of these components is usually absent from a neuron?
centrioles
The afferent division of the PNS___.
carries sensory information
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 ____ nervous system is composed of the brain and spinal cord.
central
The ____ nervous system controls the skeletal muscles
somatic
The part of the peripheral nervous system that carries sensory information to the CNS is designated ____.
afferent
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?
pseudopolar
bipolar
unipolar
multipolar
pseudopolar
Most CNS neurons fall into which structural category?
multipolar
The axon hillock connects the axon with the ___.
Cell body (soma)
The axoplasm of the axon contains which of the following?
ALL: Mitochondria, neurotubules, vesicles, neurofibrils
Which of the following is not a recognized structural classification for neurons?
pseudopolar
The most abundant class of neuron in the central nervous system is ___.
multipolar
The rabies virus travels to the CNS via
retrograde axoplasmic transport
The site of intercellular communication between neuron and another cell is the ___
synapse
Neurons that are rare, small, and lack features that distinguish dendrites from axons are called __>
anaxonic
Neurons in which dendritic and axonal processes are continuous and the soma lies off to one side are called ___.
unipolar
Neurons that have one axon and one dendrite, with the soma in between are called ___.
bipolar
Neurons that have several dendrites and a single axon are called ___.
multipolar
___ neurons are the most common class in the CNS
multipolar
___ neurons form the afferent division of the PNS.
Sensory
The basic functional unit of the nervous system is the ____
Neuron
Which is the largest and most abundant type of neuroglia?
astrocytes
Which of these types of neuroglia are abundant in peripheral ganglia?
satellite cells
The largest and most numerous of the glial cells in the central nervous system are the ?
astrocytles
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?
satellite cells
___ account for roughly half of the volume in the nervous system.
Neuroglia
The neuroglial cells that participate in maintaining the blood brain barrier are the ___
astrocytes
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
The myelin sheath that covers many CNS axons is formed by ___.
oligodendrocytes
___ line the brain ventricles and spinal cord.
Ependymal cells
Small, wandering cells that engulf cells that engulf cell debris and pathogens in the CNS are called___.
microglia
The neurilemma of axons in the peripheral nervous system is formed by __.
schwann cells
Glial cells that surround the neurons in the ganglia are ___.
satelite cells
Regions of the CNS with an abundance of myelinated axons constitute the ___ .
white matter
The events that occur at a functioning cholinergic synapse cause___.
synaptic delay
The most abundant intracellular cation is ___ while the most abundant extracellular anion is ___.
potassium, chloride
Which type of ion channel is always open?
passive
The sodium potassium exchange pump stabilizes resting potential at about___
-70 mV
____ open or close in response to binding specific molecules
Chemically-gated channels
___ channels open or close in response to physical distortion of the membrane surface.
mechanically gated
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
Voltage gated sodium channels have both an activation gate and an ____ gate.
inactivation
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
Which of these is the earliest step in the generation of an action potential?
Sodium channels open
The all or none principle states that __>
all stimuli great enough to bring the membrane to threshold will produce identical action potentials
A threshold stimulus is the ___.
depolarization necessary to cause an action potential
Which of the following is true about threshold for an action potential.
It is more positive than the resting potential
Compared to type A axons, type C axons are ___
slower propagated, unmyelinated, smaller diameter
Which of these axons will conduct an action potential most quickly?
Type A fiber
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,
A neuron that receive neurotransmitter from one neuron is called ___
the postsynaptic neuron
Which type of synapse is most common in the nervous system>
chemical
The ion that triggers the release of acetylcholine into the synaptic cleft is ___.
calcium
Cholinergic synapses release the neurotransmitter ___.
acetylcholine
Which of these neurotransmitters does not bind to a plasma membrane receptor?
nitric oxide
Which of these neurotransmitters is released at CNS adrenergic synapses?
norepinephrine
Which of these neurotransmitters do adrenergic synapses use?
norepinephine
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?
EPSPs
The neurotransmitter GABA blocks presynaptic voltage gated calcium channels. Consequently, GABA produces ___.
presynaptic inhibition