mastering a&p chap 7
What statement best describes the resting state of a neuron?
Neurons are polarized with more sodium ions outside the cell and more potassium ions inside the cell.
What cells of the nervous system are responsible for anchoring neurons to their blood vessels and controlling the extracellular fluid concentrations of potassium and neurotransmitters?
astrocytes
nervous system is the part of the brain under involuntary, or automatic, control.
autonomic
The part of the neuron that typically conducts nerve impulses away from the cell body is the
axon
What part of the neuron releases neurotransmitters from vesicles?
axon terminals
The term central nervous system refers to the
brain and spinal cord
Ganglia are collections of ___
cell bodies
The conscious part of the brain is the
cerebrum
What is the primary role of the interneuron (association neuron)?
connect motor and sensory neurons in their pathways Submit
Impulse conduction is faster in neurons that are ______
myelinated
are supporting cells of the nervous system.
neuroglia
A molecule that carries information across a synaptic cleft is a
neurotransmitter
Which of these neuroglial cells forms the myelin sheath in the central nervous system?
oligodendrocytes
During repolarization, what ions are pumped out of the cell?
potassium
Immediately after an action potential is propagated, which one of the following ions rapidly diffuses out of the cell into the tissue fluid?
potassium ions
Sensory receptors located in muscles and tendons are termed
proprioceptors
Which of these lists the components of a reflex arc in the correct sequence?
receptor; afferent neuron; control center; efferent neuron; effector
Nerve impulse transmissions occurring along myelinated neurons are called _____
saltatory conduction
What are the two main functional subdivisions of the nervous system?
sensory and motor
An action potential is caused by an influx of these ions into the cell
sodium
What are the major positive ions situated outside the neuron when it is polarized?
sodium ions
Which division of the peripheral nervous system activates skeletal muscles?
somatic
The small space between the sending neuron and the receiving neuron is the
synaptic cleft
If a signal from a sending neuron makes the receiving neuron more negative inside,
the receiving neuron is less likely to generate an action potential
When calcium ions enter the synaptic terminal,
they cause vesicles containing neurotransmitter molecules to fuse to the plasma membrane of the sending neuron.
The parasympathetic and sympathetic nervous systems are subdivisions of the autonomic nervous system.
true
Why is white matter "white"?
The region contains a high concentration of the white pigment titanium dioxide
The roots of the spinal cord on the posterior side are called
dorsal roots
Which ciliated neuroglial cell circulates cerebrospinal fluid?
ependymal cells
What type of neuron connects sensory and motor neurons in neural pathways?
interneurons (association neurons)
When neurotransmitter molecules bind to receptors in the plasma membrane of the receiving neuron
ion channels in the plasma membrane of the receiving neuron op
What are the two major functional properties of neurons?
irritability and conductivity