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