Exam 44: Neurons, Glia, and Nervous Systems

If divisions of neuronal stem cells in the neural tube of a vertebrate embryo are symmetrical rather than asymmetrical, then which of the following will result?

When an action potential reaches an axon terminal, it can cause the release of neurotransmitters into the synaptic cleft.Which of the following is a possible sequence of events that could follow?

In most vertebrate neurons, an action potential arrives at the axon terminal and causes the release of chemical messenger molecules.These molecules are

Which statement about electrical synapses is false?

Refer to the figure showing brains of various sizes and complexities.Keep in mind that the species shown can have similar body masses as adults. Which statement is false?

Evaluate the following statement: Water-soluble drugs cross the blood-brain barrier, allowing treatment of infections of the central nervous system.

In the nervous system of vertebrates, the afferent (sensory) axons in a spinal nerve enter the spinal cord via the _______ root, while the efferent (motor) axons leave through the ventral root.

Which of the following is most likely to cause the opening of a voltage-gated channel in a cell membrane?

Refer to the graphs showing action potentials occurring in response to multiple excitatory postsynaptic potentials (EPSPs). In graph B, the action potential is due to

The direction and amount of movement of ions through an ion channel depends on the concentration gradient of the ion as well as on the voltage difference across the membrane.These two forces acting on an ion are called the

If a neuron records several postsynaptic potentials in rapid succession at the same synapse, _______ summation must occur for the neuron to fire an action potential.

A disease in which antibodies destroy myelin produced by oligodendrocytes would most likely cause which of the following?

Antibodies produced by the human immune system are typically prevented from getting to the brain by the blood‒brain barrier.Does this mean that the brain has no immune defenses?

When acetylcholine binds to its receptors on the motor end plate, it triggers a(n) _______ in the postsynaptic membrane.

Nervous systems are able to encode, process, and store information because of the properties of two classes of cells: _______ cells and _______ cells.

In the neural tube of a developing vertebrate embryo, neuronal stem cells eventually divide asymmetrically, forming one daughter cell that is a neuronal stem cell and another that is either a neuroblast or a _______.

The frequency at which a single neuron can "fire" action potentials is limited by the

Briefly explain how an action potential travels more quickly down an axon wrapped in myelin than it does down an unmyelinated axon.

Glial cells are estimated to be more numerous in the brain than are neurons, yet much less is known about them.What makes glial cells so difficult to study?

Which of the following is not one of the major ions that carry electrical charges across the cell membranes of neurons?