Question 1

Synapses between neurons can be excitatory or inhibitory.How the postsynaptic neurons will respond to signals is determined by

Accepted Answer

The answer of Synapses between neurons can be excitatory or...

Question 2

Some drugs that are used to treat the nervous system act by modulating synaptic activity; drugs that enhance the effects of a neurotransmitter are known as _______, whereas those that block the effects of a neurotransmitter are called _______.

Accepted Answer

Drugs that enhance the effects of a neurotransmitter are known as agonists, whereas those that block the effects of a neurotransmitter are called antagonists. Therefore, the best choice is E.

Question 3

In the neuromuscular junction, the response of the motor end plate to the release of acetylcholine is to open cation channels.Cations then enter the muscle cell, resulting in

Accepted Answer

The influx of cations (such as sodium) into the muscle cell results in depolarization of the membrane potential, which triggers muscle contraction.

Therefore, the correct answer is:
C) depolarization.

Question 4

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

Accepted Answer

Sea stars have a nerve net in each arm, which allows for decentralized nervous control and little integration of signals. However, they do not have a single ganglion in each arm. Instead, sea stars have a centralized nerve ring in the center of their body from which the nerve nets in each arm radiate.

Question 5

If you were to design an axon with low resistance to ionic current flow, you would make

Accepted Answer

A large-diameter axon in an invertebrate has low resistance to ionic current flow due to its ability to accommodate a greater number of ions. This is in contrast to vertebrates, where myelinated axons with small diameters are used to reduce resistance and improve signal conduction speed.

Question 6

During limb movement, one muscle of a pair contracts while the antagonistic muscle relaxes.The interneuron that inhibits firing in the motor neuron for the antagonistic muscle is located in the _______ of the _______.

Accepted Answer

The interneuron that inhibits firing in the motor neuron for the antagonistic muscle is located in the gray matter of the spinal cord. This is because the spinal cord is responsible for processing sensory information and generating motor output, and the gray matter contains the cell bodies of interneurons and motor neurons. The dorsal root carries sensory information into the spinal cord, while the ventral root carries motor output out of the spinal cord. The white matter of the spinal cord contains axons that connect different regions of the spinal cord and relay information up and down the spinal cord to the brain.

Question 7

All of the following characterize reflexes except

Accepted Answer

Reflexes are automatic and do not involve conscious information processing.

Question 8

What type of synapse is the neuromuscular junction?

Accepted Answer

The neuromuscular junction is a chemical synapse where neurotransmitters (acetylcholine) are released from the presynaptic neuron to bind with receptors on the postsynaptic muscle cell, leading to muscle contraction.

Question 9

Because birds have forelimbs specialized for flight, most rely on their beaks to build nests.Controlling for body size, you might expect bird species that build nests requiring complex beak movements and fine motor control to have a larger _______ than bird species that build nests requiring only simple movements.

Accepted Answer

The cerebellum is responsible for fine motor control and coordination of movements. Bird species that build nests requiring complex movements and fine motor control of their beaks would need a larger cerebellum.

Question 10

Chemical synapses differ from electrical synapses in that they

Accepted Answer

Chemical synapses allow for a greater variety of postsynaptic responses as they can utilize different neurotransmitters and receptor types, whereas electrical synapses have fixed, uniform properties.

Quiz 44: Neurons, Glia, and Nervous Systems