Exam 44: Neurons, Glia, and Nervous Systems

In a neuron at rest, there is a difference in the electrical charge across the cell membrane, with the inside of the cell being more negative than the outside.This is primarily due to

In looking at a section through the brain, you see a neuron with a number of shrublike projections extending from one side of the cell body and a single long projection extending from the other side.The shrublike projections are most likely _______, and the single long projection is most likely _______.

Sea stars have a nerve net in each arm.All of the following characterize sea stars except

Why is it important for a neuron to maintain a membrane potential instead of allowing ions to reach equal concentrations on the two sides of the membrane?

A particular disease of the nervous system specifically involves the Ca²⁺ channels at the chemical synapses of motor neurons where neurotransmitter is stored and released.This disease therefore affects the

Which of the following is not a function of astrocytes?

Which statement about neuronal membranes is false?

The blood-brain barrier can make it difficult to deliver therapeutic drugs to treat brain disorders.The composition of the blood-brain barrier makes it most easily crossed by

A physical or chemical stimulus can produce a change in a cell's membrane potential by changing the

Earthworms and squid have clusters of neurons called

Which statement about microglia is true?

Which statement about the knee-jerk reflex is true?

What type of synapse is the neuromuscular junction?

In vertebrates, most cells of the nervous system are found in the

Ion transporters and ion channels both contribute to membrane potentials but differ in their requirement for

The neurons involved in a polysynaptic reflex such as the withdrawal reflex are an afferent neuron, an efferent neuron, and _______.

The tripartite synapse model describes the arrangement of _______, _______, and _______.

Action potentials cannot propagate under myelin sheaths because there are no sodium or _______ channels.

To maintain the resting potential of the nerve cell membrane, the sodium‒potassium pump keeps the concentration of

Following the spike of an action potential, the return to resting membrane potential is facilitated by