Question 1

The branches at the end of the axon are called __________.

Accepted Answer

The branches at the end of the axon are called axon terminals or terminal buttons. They are responsible for communicating with other neurons or muscle cells through the release of neurotransmitters. Synaptic vesicles refer specifically to the small sacs contained within the axon terminals that hold the neurotransmitters. Synapses are the tiny gaps between neurons where transmission occurs, and receptor sites are areas on the surface of a cell that receive specific neurotransmitters.

Question 2

When a neuron fires,it fires in a(n)__________ fashion as there is no such thing as "partial" firing.

Accepted Answer

Neurons follow the all-or-none principle, which means that they either fire at full strength or not at all. There is no partial firing or in-between state.

Question 3

Curare,a poison,works by ______.

Accepted Answer

Curare works by blocking receptor sites and acting as an antagonist for acetylcholine. This prevents acetylcholine from binding to its receptors, which leads to muscle paralysis and ultimately death.

Question 4

Sara has been experiencing a serious memory problem.An interdisciplinary team has ruled out a range of causes and believes that a neurotransmitter is involved.Which neurotransmitter is most likely involved in this problem?

Accepted Answer

Acetylcholine is a neurotransmitter that plays a crucial role in memory processes. Its deficiency has been linked to memory impairment and Alzheimer's disease. Therefore, it is the most likely candidate involved in Sara's memory problem. GABA, dopamine, and serotonin are not primarily associated with memory processes.

Question 5

The saclike structures found inside the synaptic knob containing chemicals are called__________.

Accepted Answer

Synaptic vesicles are the sac-like structures found inside the synaptic knob that contain chemicals, commonly neurotransmitters, which are used for communication between neurons at the synapse. Axon terminals are the tips of the axons that make contact with other neurons or muscle cells. Synapses are the small gaps between neurons across which chemical or electrical signals can be transmitted. Receptor sites are specific areas on the postsynaptic membrane where neurotransmitters bind to initiate a signal transduction pathway.

Question 6

Which of the following are tiny sacs in a synaptic knob that release chemicals into the synapse?

Accepted Answer

Synaptic vesicles are small, membrane-bound sacs located in the synaptic knob of a neuron. They contain neurotransmitters, which are released into the synapse when the neuron fires.

Question 7

The action potential causes neurotransmitters to be released into the __________.

Accepted Answer

The synapse is the small gap or junction between the axon of one neuron and the dendrite or cell body of another neuron or a muscle cell. When an action potential reaches the end of an axon, it triggers the release of neurotransmitters from the synaptic vesicles located in the terminal buttons of the presynaptic neuron. These neurotransmitters then diffuse across the synapse and bind to receptors on the postsynaptic neuron or muscle cell, causing a response in the receiving cell.

Question 8

__________ are holes in the surface of the dendrites or certain cells of the muscles and glands that are shaped to fit only certain neurotransmitters.

Accepted Answer

Receptor sites are specifically designed to fit certain neurotransmitters like a key in a lock. These receptor sites are located on the surface of dendrites or certain cells of muscles and glands.

Question 9

A chemical found in the synaptic vesicles which,when released,has an effect on the next cell is called a__________.

Accepted Answer

A neurotransmitter is a chemical released by a neuron into the synapse, which can bind to receptors on the next cell and have an effect. Glial cells are support cells in the nervous system, precursor cells are immature cells that can differentiate into other types of cells, and a synapse is the junction between two neurons.

Question 10

What is the term used to describe the branches located at the end of the axon?

Accepted Answer

The branches located at the end of the axon are called axon terminals.

Question 11

The fluid-filled space between the synaptic knob of one cell and the dendrites of the next cell is called the ___________.

Accepted Answer

The fluid-filled space between the synaptic knob of one cell and the dendrites of the next cell is called the synapse. The receptor site is the specific location on the receiving neuron where neurotransmitters bind. The synaptic knob (also known as the axon terminal) is the bulb-shaped structure at the end of an axon that releases neurotransmitters. Therefore, the best choice is B.

Question 12

Your teacher asks you to describe the sequence of parts of a neuron that the impulse travels down during neural conduction.Which of the following sequences will you offer?

Accepted Answer

The correct sequence is dendrites, soma (cell body), axon, and synaptic knob. The impulse is received by the dendrites, processed in the soma, travels down the axon, and reaches the synaptic knob to be transmitted to the next neuron.

Question 13

What is the term used to describe the rounded areas on the ends of the axon terminals?

Accepted Answer

The rounded areas on the ends of the axon terminals are called synaptic knobs, also known as synaptic boutons or terminal boutons.

Question 14

The poison of the black widow spider works by stimulating the release of excessive amounts of ______.

Accepted Answer

The poison of the black widow spider contains a neurotoxin that stimulates the release of excessive amounts of acetylcholine, which is a neurotransmitter that controls muscle movement and can lead to muscle rigidity and spasms in humans.

Question 15

Which structure is like a locked door that only certain neurotransmitter keys can unlock?

Accepted Answer

Receptor sites are like a locked door that only certain neurotransmitter keys can unlock. They are specialized protein molecules located on the surface of the dendrites or cell body of a neuron, and they bind to specific neurotransmitters like a key fits into a lock. This process initiates a chemical signal that can either excite or inhibit the neuron.

Question 16

The term neurotransmitter refers to __________.

Accepted Answer

Neurotransmitters are chemicals that are released from the synaptic vesicles of a neuron into the synapse, where they bind to receptors on the postsynaptic neuron or other target cells to transmit a signal. They are not related to the endocrine system, cell membrane or DNA.

Question 17

______ plays a critical role as a neurotransmitter that stimulates muscles to contract.

Accepted Answer

Acetylcholine is a neurotransmitter that plays a critical role in stimulating muscles to contract. It is also involved in many other functions such as regulating attention, learning, and memory.

Question 18

After being bitten by a black widow spider,Jean starts to convulse.This is a result of _____.

Accepted Answer

When bitten by a black widow spider, the venom causes a flood of acetylcholine to be released into the body's muscle system, which can lead to convulsions.

Question 19

____________neurotransmitters make it more likely that a neuron will send its message to other neurons,whereas _____________ neurotransmitters make it less likely that a neuron will send its message.

Accepted Answer

Excitatory neurotransmitters stimulate and increase the likelihood of neuron firing and transmitting messages to other neurons, while inhibitory neurotransmitters decrease the likelihood of neuron firing and transmitting messages to other neurons. Therefore, choice A is correct.

Question 20

"All or none" is the principle stating that __________.

Accepted Answer

The "all or none" principle refers to the fact that a neuron will either fire at full strength or not at all. It does not refer to the mechanism of firing, as described in options B, C and D.

Quiz 2: The Biological Perspective