Question 1

Myasthenia gravis is a chronic autoimmune disease that causes weakness in skeletal muscle.It develops when a person's antibodies block or destroy _______ nicotinic receptors.

Accepted Answer

Myasthenia gravis results from the immune system attacking acetylcholine (ACh) receptors on muscle cells, leading to muscle weakness. ACh is a neurotransmitter that transmits signals between nerves and muscles, and the nicotinic ACh receptors are necessary for muscle contraction. Therefore, the correct option is B) acetylcholine.

Question 2

Which statement about the process of summation in a neuron is false?

Accepted Answer

The concentration of voltage-gated sodium channels is actually highest at the axon hillock, not the dendrites of the postsynaptic cell. This is important for the initiation of action potentials.

Question 3

If the proteins that anchor acetylcholine-containing vesicles to the presynaptic membrane are damaged by botulism toxins, what effect will this have on the neuromuscular junction?

Accepted Answer

The proteins that anchor acetylcholine-containing vesicles to the presynaptic membrane are called SNARE proteins. Botulism toxins damage these proteins, preventing the fusion of the vesicle membrane with the presynaptic membrane and the subsequent release of acetylcholine into the synaptic cleft. This will result in a decrease or cessation of neuromuscular transmission.

Question 4

When you decide to mark a particular answer to this question, your nervous system sends the command to your hand to do so.That command is carried to your hand by

Accepted Answer

Efferent neurons carry signals away from the central nervous system to muscles or glands, allowing for motor commands like marking a particular answer.

Question 5

Refer to the figure showing a neuromuscular junction.  Which cellular event is paired correctly with the location where it occurs?

Accepted Answer

The answer of Refer to the figure showing a neuromuscular...

Question 6

Information about a sensory stimulus such as touch can be prevented from reaching the central nervous system by chemically blocking

Accepted Answer

Afferent neurons carry sensory information from the sensory cells to the central nervous system. Chemically blocking these neurons would prevent the sensory stimulus from reaching the central nervous system. The other choices (A, C, D, and E) do not accurately describe how sensory information is blocked from reaching the central nervous system.

Question 7

Which of the following is not necessary for the formation of a neural network?

Accepted Answer

While a brain is essential in some neural networks, it is not necessary for the formation of all neural networks. Simple reflexive pathways, such as the knee-jerk reflex, can exist without the presence of a brain. Therefore, answer choice D is not necessary for the formation of a neural network.

Question 8

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

Accepted Answer

The answer of Refer to the graphs showing action potentials...

Question 9

Which statement about the summation of postsynaptic potentials is false?

Accepted Answer

Option C is false, as a neuron can receive both excitatory and inhibitory input simultaneously.

Question 10

Which experimental stimulus would most likely produce the greatest response in a postsynaptic neuronal membrane?

Accepted Answer

A repeated stimulus occurring at different sites on the postsynaptic cell is most likely to produce the greatest response because it can lead to temporal and spatial summation, increasing the likelihood of reaching the threshold for an action potential.

Question 11

Which statement about electrical synapses is false?

Accepted Answer

Electrical synapses involve gap junctions, which are crucial for their function, allowing direct cytoplasmic connections between cells for the passage of ions and signaling molecules. Therefore, gap junctions are not rare at electrical synapses; they are a fundamental component.

Question 12

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

Accepted Answer

The Ca²⁺ channels are responsible for the influx of calcium ions into the presynaptic neuron, triggering the release of neurotransmitter, specifically acetylcholine in this case. Therefore, a disease involving these channels would affect the release of acetylcholine from the axon terminals of the presynaptic cell.

Question 13

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

Accepted Answer

The answer of Refer to the graphs showing action potentials...

Question 14

The binding of acetylcholine results in a(n) _______ in the motor end plate membrane.

Accepted Answer

The binding of acetylcholine to the motor end plate results in the opening of ion channels, which leads to a graded potential. This graded potential can then trigger an action potential in the muscle fiber. Therefore, choice A is the best answer. Choices B, C, D, and E are all incorrect because they do not accurately describe the physiological response to the binding of acetylcholine in the motor end plate.

Question 15

Which statement about the ganglia of invertebrates is true?

Accepted Answer

Ganglia are clusters of nerve cells found in many organisms, including invertebrates. When a large set of these ganglia are fused together at the anterior (front) end of an organism, they can form a structure that functions similarly to a brain, integrating sensory information and coordinating the organism's responses. This is a common feature in more complex invertebrates, where it serves as a central processing unit for the nervous system.

Question 16

If the clearance of neurotransmitter from the synaptic cleft is prevented, which of the following will be the most likely result?

Accepted Answer

If the clearance of neurotransmitter from the synaptic cleft is prevented, the postsynaptic cell will be constantly activated by the buildup of neurotransmitter. The excess neurotransmitter will continue to bind to the receptors on the postsynaptic cell, causing continuous activation and potentially leading to overexcitation and cell damage. This can lead to disorders such as epilepsy or neurodegeneration. The other options (A, B, C, and D) do not accurately reflect the consequences of inhibited clearance of neurotransmitter.

Question 17

Which statement about the withdrawal response to stepping on a piece of broken glass is false?

Accepted Answer

The statement that the withdrawal reflex involves a simpler neural circuit than the knee-jerk reflex is false. The withdrawal reflex involves more complex neural circuits and multiple sensory inputs, while the knee-jerk reflex is a simple monosynaptic reflex.

Question 18

Refer to the figure showing a neuromuscular junction.  Which event is occurring at position 5?

Accepted Answer

Position 5 is the motor end plate, where acetylcholine binding causes the opening of sodium channels and subsequent depolarization of the postsynaptic membrane. This is known as the end plate potential. Option A is incorrect because acetylcholine has already been released from the presynaptic neuron and is now binding to receptors on the postsynaptic membrane. Option B is incorrect because the opening of calcium channels occurs in the presynaptic neuron during neurotransmitter release, not at the motor end plate. Option C is incorrect because the end plate potential is an all-or-nothing response, not a graded potential. Option E is incorrect because acetylcholinesterase breaks down acetylcholine in the synaptic cleft, not at the motor end plate.

Question 19

Sea stars are marine animals that have the simplest form of nervous system, a _______, located in each arm.

Accepted Answer

Sea stars have a nerve net, which is the simplest form of a nervous system, located in each of their arms. This allows them to sense their environment and coordinate their movements without a centralized brain.

Question 20

A chemical synapse differs from an electrical synapse in that a chemical synapse

Accepted Answer

Chemical synapses allow for a greater diversity and number of synaptic inputs per cell compared to electrical synapses. This is because chemical synapses use neurotransmitters to communicate between neurons, allowing for complex modulation and integration of signals from multiple sources.

Quiz 44: Neurons, Glia, and Nervous Systems

Myasthenia gravis is a chronic autoimmune disease that causes weakness in skeletal muscle.It develops when a person's antibodies block or destroy _______ nicotinic receptors.

Which statement about the process of summation in a neuron is false?

If the proteins that anchor acetylcholine-containing vesicles to the presynaptic membrane are damaged by botulism toxins, what effect will this have on the neuromuscular junction?

When you decide to mark a particular answer to this question, your nervous system sends the command to your hand to do so.That command is carried to your hand by

Refer to the figure showing a neuromuscular junction. Which cellular event is paired correctly with the location where it occurs?

Information about a sensory stimulus such as touch can be prevented from reaching the central nervous system by chemically blocking

Which of the following is not necessary for the formation of a neural network?

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

Which statement about the summation of postsynaptic potentials is false?

Which experimental stimulus would most likely produce the greatest response in a postsynaptic neuronal membrane?

Which statement about electrical synapses is false?

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

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

The binding of acetylcholine results in a(n) _______ in the motor end plate membrane.

Which statement about the ganglia of invertebrates is true?

If the clearance of neurotransmitter from the synaptic cleft is prevented, which of the following will be the most likely result?

Which statement about the withdrawal response to stepping on a piece of broken glass is false?

Refer to the figure showing a neuromuscular junction. Which event is occurring at position 5?

Sea stars are marine animals that have the simplest form of nervous system, a _______, located in each arm.

A chemical synapse differs from an electrical synapse in that a chemical synapse

Quiz 44: Neurons, Glia, and Nervous Systems

Myasthenia gravis is a chronic autoimmune disease that causes weakness in skeletal muscle.It develops when a person's antibodies block or destroy _______ nicotinic receptors.

Which statement about the process of summation in a neuron is false?

If the proteins that anchor acetylcholine-containing vesicles to the presynaptic membrane are damaged by botulism toxins, what effect will this have on the neuromuscular junction?

When you decide to mark a particular answer to this question, your nervous system sends the command to your hand to do so.That command is carried to your hand by

Refer to the figure showing a neuromuscular junction. Which cellular event is paired correctly with the location where it occurs?

Information about a sensory stimulus such as touch can be prevented from reaching the central nervous system by chemically blocking

Which of the following is not necessary for the formation of a neural network?

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

Which statement about the summation of postsynaptic potentials is false?

Which experimental stimulus would most likely produce the greatest response in a postsynaptic neuronal membrane?

Which statement about electrical synapses is false?

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

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

The binding of acetylcholine results in a(n) _______ in the motor end plate membrane.

Which statement about the ganglia of invertebrates is true?

If the clearance of neurotransmitter from the synaptic cleft is prevented, which of the following will be the most likely result?

Which statement about the withdrawal response to stepping on a piece of broken glass is false?

Refer to the figure showing a neuromuscular junction. Which event is occurring at position 5?

Sea stars are marine animals that have the simplest form of nervous system, a _______, located in each arm.

A chemical synapse differs from an electrical synapse in that a chemical synapse

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