lecture test 1 human anatomy: chapter 12
Which of the channels shown in the figure opens and closes randomly
A
Which of the labeled cells in the diagram is a neuroglial cell that forms and maintains the myelin sheath around CNS axons?
A
Which of these types of channels is involved in leaking sodium and potassium ions across the membrane in order to establish the resting potential of a cell?
A
In the diagram, where is a node of Ranvier?
B
Which of the diagrams in the figure represents a ligand-gated channel?
B
Which of the labeled cells in the diagram is a neuroglial cell that removes debris and acts as a phagocyte?
B
this part of the neuron contains the nucleus and Nissl bodies.
B
This type of neuron has one dendrite and one axon emerging from the cell body.
Bipolar neuron
Which part of the diagram is considered nerve fiber?
Both A and D
Chromatolysis refers to
Break up of Nissl bodies after neural injury.
Which diagram represents a reverberating circuit?
C
Which of the labeled cells in the figure is NOT a neuroglial cell?
C
Which type of circuit is used to lengthen the output signal in physiological processes like regulation of the breathing pattern?
C
Which type of circuit is involved in solving mathematical problems?
D
This type of neural circuit consists of a single presynaptic neuron synapsing with several postsynaptic neurons.
Diverging circuit
In the CNS, this structure is produced by oligodendrocytes.
E
This part of a neuron contains the nucleus and cytoplasm of the Schwann's cell that has formed a myelin sheath around the axon.
E
This structure electrically insulates the axon of a neuron to increase the speed of nerve impulse conduction.
E
In the process of spatial summation, _____ are added together and _____ are subtracted from that total to determine whether _____ will be created at the trigger zone of the postsynaptic neuron.
EPSPs; IPSPs; action potentials
Which of the labeled cells in the diagram is a neuroglial cell that produces and assists in the circulation of cerebrospinal fluid?
F
In the diagram, where are axon terminals?
H
Which of the following is NOT a type of channel used in production of electrical signals in neurons?
Ion-gated channel
Which of the following types of neurons is exclusively found in the cerebellum?
Purkinje cells
During this period, a second action potential can only be initiated by a larger than normal stimulus
Relative refractory period
Hearing your cell phone ring in an otherwise quiet lecture hall is an example of which of the following types of nervous system functions?
Sensory function
What specific type of unipolar neuron is shown in the diagram labeled B?
Type I cutaneous mechanoreceptor (Merkel disc)
Plasticity means
ability to change based on experience.
Which of the neurons is considered to be a bipolar neuron?
all of the neurons
Which of the following structures is labeled E in the diagram?
axon terminal
Which type of depression results in an individual with a manic-depressive illness.
bipolar disorder.
What is the structural classification of the neuron labeled B?
bipolar neuron
Which of the following types of neurons have one axon and one dendrite emerging from the cell body and are found in the retina of the eye, inner ear, and olfactory region of the brain?
bipolar neuron
During the resting state of a voltage-gated Na+ channel, 1. the inactivation gate is open. 2. the activation gate is closed. 3. the channel is permeable to Na+.
both 1 and 2 are true.
With respect to neurons, the term "nerve fiber" refers to
both axons and dendrites.
Which of the following structures is labeled C in the diagram?
cell body
The nervous system can distinguish between a light touch and a heavier touch by
changing the frequency of impulses sent to sensory centers.
The motor portion of the autonomic nervous system can be divided into
d) sympathetic and parasympathetic divisions.
Wallerian degeneration refers to
degeneration of the distal end of axon and myelin sheath after neural injury.
Which of the following structures is labeled A in the diagram?
dendrites
An excitatory neurotransmitter _____ the postsynaptic membrane.
depolarizes
Schwann's cells begin to form myelin sheaths around axons in the peripheral nervous system
during fetal development.
A postsynaptic neuron responds to neurotransmitters released by a presynaptic neuron by creating
either EPSPs or IPSPs
Faster communication and synchronization are two advantages of
electrical synapses
In temporal summation, a single presynaptic neuron stimulates the creation of action potentials in a postsynaptic neuron when it
fires at a fast enough rate that the sum of EPSPs in the postsynaptic neuron moves above threshold.
Which of the following neurotransmitters are used in virtually all of the inhibitory synapses found in the spinal cord?
gamma aminobutyric acid (GABA) and glycine
In an action potential, the current that flows down the axon of a neuron is generated by the movement of _____ across the membrane.
ions
Name the type of membrane channel that randomly opens and closes and is found in dendrites, cell bodies, and axons of all types of neurons.
leakage channel
Name the type of membrane channel that opens in response to chemical binding and is found in dendrites of some sensory receptors like pain receptors, and in the dendrites and cell bodies of interneurons and motor neurons.
ligand-gated channels
A depolarizing graded potential
makes the membrane less polarized.
Name the type of membrane channel that opens in response to touch, pressure, vibration, or tissue stretching and is found in the auditory receptors of the ear, and in touch and pressure receptors in the skin.
mechanically gated channels
Which of the following types of neurons is the most common type of neuron found in the brain and spinal cord?
multipolar neuron
Which of the following types of cells display the property of electrical excitability?
muscle cells and neurons
Which of the following types of electrical signals allow rapid long-distance communication within the nervous system?
nerve action potential
Saltatory conduction
occurs only in myelinated axons
Which of the following structures is labeled B in the diagram?
peripheral process
Diffusion, enzymatic degradation, and uptake by cells are all ways to
remove a neurotransmitter
Which of the following structures is labeled D in the diagram?
trigger zone
When a depolarizing graded potential makes the axon membrane depolarize to threshold,
voltage-gated Na+ channels open rapidly.
Name the type of membrane channel that opens in response to changes in membrane potential and is located in axons of all types of neurons.
voltage-gated channels