202 Bio Ch 11 Test

Which of the following types of glial cells are the most abundant and versatile, and aid in making exchanges between capillaries and neurons? oligodendrocytes astrocytes ependymal cells microglia

Astrocytes.

What is the difference between nerves and tracts? Bundles of neuron processes are called nerves in the CNS and tracts in the PNS. Bundles of neuron processes are called tracts in the CNS and nerves in the PNS. Tracts are bundles of neuron processes and nerves are the conducting regions of neurons. Tracts are composed of many nerves wrapped into long, rope-like extensions.

Bundles of neuron processes are called tracts in the CNS and nerves in the PNS. Bundles of neuron processes are called tracts in the CNS and nerves in the PNS.

Which of the following is NOT a functional classification of neurotransmitters? chemical direct indirect excitatory

Chemical

Which of the following are the main receptive or input regions found in neurons? axons dendrites ganglia neurofibrils

Dendrites. Dendrites are the main receptive or input regions found in neurons.

Which of the following circuit types is exemplified by impulses that travel from a single neuron of the brain, activate one hundred or more motor neurons in the spinal cord, and excite thousands of skeletal muscle fibers? after-discharge circuits diverging circuits reverberating circuits converging circuits

Diverging circuits In diverging circuits, one incoming fiber triggers responses in ever-increasing numbers of neurons farther and farther along in the circuit. Therefore, diverging circuits are often amplifying circuits. Divergence can occur along a single pathway or along several.

Which of the following is NOT true of efferent neurons? Efferent neurons are bipolar. The cell bodies of most efferent neurons are located in the CNS. Efferent neurons carry impulses away from the CNS to the effector organs. Impulses from efferent neurons cause activity in skeletal muscles and glands.

Efferent neurons are bipolar. Motor, or efferent, neurons carry impulses away from the CNS to the effector organs (muscles and glands) of the body periphery. Motor neurons are multipolar. Except for some neurons of the autonomic nervous system, their cell bodies are located in the CNS.

Which of the following types of glial cells line the central cavities of the brain and spinal cord, where they help to circulate the cerebrospinal fluid? astrocytes microglia ependymal cells oligodendrocytes

Ependymal cells.

Which type of ion channel opens when a chemical binds to it? ligand-gated channels leakage channels mechanically gated channels voltage-gated channels

Leakage channels Leakage channels are always open. Ligand-gated channels open when the appropriate chemical binds. Voltage-gated channels open and close in response to changes in the membrane potential. Mechanically gated channels open in response to physical deformation of the receptor.

Which of the following diseases is directly related to demyelination? muscular dystrophy multiple sclerosis cerebral palsy lupus

Multiple sclerosis The importance of myelin nerve transmission is painfully clear to people with demyelinating diseases such as multiple sclerosis (MS).

Which of the following is NOT a characteristic of neurons? In general, neurons cannot be replaced if destroyed. Neurons require continuous and abundant supplies of oxygen, and cannot survive for more than a few minutes without it. Neurons can function optimally for over 100 years. Neurons are relatively small, simple-structured cells.

Neurons are relatively small, simple-structured cells.

What is the difference between the clusters of cell bodies called nuclei and those known as ganglia? Nuclei exist in the PNS, ganglia in the CNS. Nuclei exist in all cells throughout the body, and ganglia exist only within the brain and spinal cord. There is no difference between nuclei and ganglia. Nuclei exist in the CNS, ganglia in the PNS.

Nuclei exist in the CNS, ganglia in the PNS.

The movement of which ion through leakage channels establishes the negative membrane potential? sodium chloride calcium potassium

Potassium

Which part of the action potential occurs when the Na+ channels are inactivating and K+ channels open? repolarization depolarization hyperpolarization resting state

Repolarization

Which of the following is NOT a structural classification of neurons? unipolar sensory bipolar multipolar

Sensory Sensory is a functional classification, not a structural classification.

Which of the following best describes the concept of integration? The nervous system processes and interprets sensory input and decides what should be done at each moment. The nervous system generates neurons in order to replace or repair damaged neurons; this permits optimal communication between the CNS and the body's effector organs. The nervous system uses its millions of sensory receptors to monitor changes occurring both inside and outside the body. The nervous system causes a response by activating effector organs, such as the muscles and glands.

The nervous system processes and interprets sensory input and decides what should be done at each moment. The nervous system processes and interprets sensory input and decides what should be done at each moment—a process called integration.

Which criterion is used to structurally classify neurons? the direction the nerve impulse travels relative to the central nervous system whether the nerve fibers are myelinated or not the number of processes extending from their cell body whether the neurons are found within the CNS or the PNS

The number of processes extending from their cell body.

What is the primary difference between the somatic nervous system and the autonomic nervous system? The somatic nervous system enables us to control our involuntary muscles, while the autonomic nervous system controls our glands. The autonomic nervous system enables us to control our involuntary muscles, while the somatic nervous system controls our glands. The somatic nervous system allows us to consciously control our skeletal muscles, and the autonomic nervous system controls activity that humans cannot consciously control, such as the pumping of the heart and the movement of food through the digestive tract. The autonomic nervous system allows us to consciously control our skeletal muscles, and the somatic nervous system controls activity that humans cannot consciously control, such as the pumping of the heart and the movement of food through the digestive tract.

The somatic nervous system allows us to consciously control our skeletal muscles, and the autonomic nervous system controls activity that humans cannot consciously control, such as the pumping of the heart and the movement of food through the digestive tract.

Which of the following is NOT true of chemical synapses? They possess pre- and postsynaptic membranes separated by a synaptic cleft. They transmit nerve impulses directly from one neuron to another. Each is composed of an axon terminal and a receptor region. They communicate unidirectionally.

They transmit nerve impulses directly from one neuron to another. In contrast to electrical synapses, which are specialized to allow the flow of ions between neurons, chemical synapses are specialized for release and reception of chemical neurotransmitters. A typical chemical synapse is made up of two parts: A knoblike axon terminal of the presynaptic neuron, which contains many tiny, membrane-bounded sacs called synaptic vesicles, each containing thousands of neurotransmitter molecules A neurotransmitter receptor region on the membrane of a dendrite or the cell body of the postsynaptic neuron Presynaptic and postsynaptic membranes are always separated by the synaptic cleft, a fluid-filled space approximately 30-50 nm wide. As a result, nerve impulses are not directly transmitted from one neuron. to another.

Which of the following is NOT a function of the myelin sheath? to protect nerve fibers to electrically insulate nerve fibers to recapture and recycle released neurotransmitters to increase the speed of transmission of nerve impulses

To recapture and recycle released neurotransmitters. Recapturing and recycling released neurotransmitters is a function of astrocytes, not the myelin sheath.

An action potential is a phenomenon that either happens completely or doesn't happen at all. True False

True

Dendrites and axons are both armlike processes that extend from cell bodies. True False

True

Which of the following membrane ion channels open and close in response to changes in the membrane potential? chemically gated channels mechanically gated channels non-gated channels voltage-gated channels

Voltage-gated channels