Chapter 38 Nervous System Quiz

Different aspects of language comprehension are controlled by different parts of the brain. This explanation suggests that language comprehension involves different processes that are localized in different regions of the brain. In the case of someone who can comprehend written language but not spoken language, it implies that the specific regions responsible for processing spoken language may have been damaged while the regions responsible for processing written language remain intact. This supports the idea that language processing is not a singular process but rather involves multiple specialized areas of the brain.

The correct answer is sensory neurons (for stimuli), interneurons (to receive signals for sensory neurons), motor neurons (to receive instructions from sensory neurons), effectors (tissue to perform the response). This answer accurately identifies the four elements controlled by the nervous system of humans. Sensory neurons detect stimuli from the environment, interneurons receive signals from sensory neurons and transmit them to other neurons, motor neurons receive instructions from sensory neurons and control muscle movement, and effectors are the tissues that carry out the response to the stimuli.

The sympathetic division of the autonomic nervous system is responsible for involuntary responses to extreme danger or stress. This includes the fight-or-flight response, where the body prepares to either confront the threat or escape from it. In this state, the body releases stress hormones, increases heart rate, dilates blood vessels, and redirects blood flow to the muscles. These physiological changes help to mobilize the body's resources and increase its chances of survival in a dangerous or stressful situation.

The nucleus of a neuron is located in its cell body. The cell body, also known as the soma, contains the nucleus along with other organelles necessary for the neuron's functioning. The nucleus plays a vital role in controlling the activities of the neuron by containing the genetic material and regulating gene expression. It is responsible for important functions such as protein synthesis and maintaining the overall health and functioning of the neuron.

The autonomic nervous system is part of the peripheral nervous system. It controls involuntary bodily functions such as heart rate, digestion, and breathing. The medulla, thalamus, brain, and spinal cord are all part of the central nervous system, which is responsible for processing and coordinating information. Therefore, the autonomic nervous system is the correct answer as it is the only option that is part of the peripheral nervous system.

When a signal from a sending neuron makes the receiving neuron more negative inside, it means that the receiving neuron is becoming more polarized or hyperpolarized. This hyperpolarization makes it more difficult for the receiving neuron to reach the threshold required to generate an action potential. Therefore, the receiving neuron is less likely to generate an action potential in this scenario.

Acetylcholine is the correct answer because it is the neurotransmitter that stimulates skeletal muscle cells. When released from motor neurons, acetylcholine binds to receptors on the muscle cells, causing them to contract. This neurotransmitter plays a crucial role in muscle movement and coordination. Norepinephrine, glycine, and nitric oxide are not directly involved in stimulating skeletal muscle cells.

The correct answer is synapse. The synapse is the site where a neuron communicates with another cell, either another neuron or an effector cell such as a muscle or gland. It is a small gap between the axon terminal of one neuron and the dendrites or cell body of the receiving neuron or cell. Neurotransmitters are released from the axon terminal into the synapse, where they bind to receptors on the receiving cell, allowing for the transmission of signals between cells.

The speed of conduction of an action potential from the cell body to the dendrites of another cell is increased by a fatty insulation called myelin covering the axon. The myelin sheath acts as an insulator and helps to prevent the loss of electrical signals along the axon. This allows the action potential to travel faster and more efficiently.

The resting potential of a neuron refers to its electrical charge when it is not actively sending signals. A resting potential of -70 millivolts means that the inside of the neuron is negatively charged compared to the outside. This negative charge is maintained by the balance of ions across the neuron's cell membrane. This value of -70 millivolts is considered the typical resting potential for most neurons.

Nerve impulses move toward a neuron's cell body along dendrites. Dendrites are the branched extensions of a neuron that receive signals from other neurons and transmit them towards the cell body. They play a crucial role in integrating incoming signals and initiating the transmission of nerve impulses within the neuron. Synaptic terminals are located at the end of axons and are responsible for transmitting signals to other neurons. Oligodendrocytes are a type of glial cell that provides support and insulation to axons. Axons are long, slender extensions of a neuron that transmit nerve impulses away from the cell body. Nodes of Ranvier are small gaps in the myelin sheath of axons where the nerve impulses are regenerated.

The primary function of a neuron is to receive, process, and transmit information. Neurons are specialized cells in the nervous system that receive electrical signals from other neurons through their dendrites. These signals are then processed in the cell body and transmitted to other neurons through the axon. This communication between neurons allows for the transmission of information throughout the nervous system, enabling various functions such as sensory perception, motor control, and cognitive processes.

When a nerve impulse is transmitted, it triggers the opening of voltage-gated sodium channels. This allows sodium ions to diffuse into the neuron. This influx of sodium ions creates a positive charge inside the neuron, which leads to the generation of an action potential and the transmission of the nerve impulse along the neuron.

The space between an axon of one neuron and the dendrite of another neuron is called a synaptic cleft. This is the small gap where neurotransmitters are released from the axon terminal of one neuron and received by the dendrite of another neuron, allowing for communication between neurons. The synaptic cleft plays a crucial role in the transmission of signals in the nervous system.

The cerebrum is responsible for memory, sensory processing, motor responses, creativity, and higher intellectual functions. It is the largest part of the brain and is divided into two hemispheres. The cerebrum is involved in complex cognitive processes such as thinking, reasoning, problem-solving, and language processing. It also plays a crucial role in controlling voluntary movements and interpreting sensory information from the environment. The other options, such as the amygdala, medulla, cerebellum, and hypothalamus, have specific functions but are not primarily responsible for the wide range of cognitive processes mentioned in the question.

The fact that single axons may stretch from the spinal cord to the toes suggests that the axon can conduct action potentials over long distances. This implies that the axon is capable of transmitting electrical signals from one end to the other, allowing for communication between different parts of the body. It also highlights the efficiency and effectiveness of axonal conduction in transmitting signals over such long distances.

When calcium ions enter the synaptic terminal, they cause vesicles containing neurotransmitter molecules to fuse to the plasma membrane of the sending neuron. This fusion allows the neurotransmitter molecules to be released into the synaptic cleft, where they can then bind to receptors on the receiving neuron. This binding of neurotransmitters to receptors triggers a response in the receiving neuron, such as the opening or closing of ion channels, which can ultimately lead to changes in the electrical activity of the receiving neuron.

The statement "The stronger the stimulus, the more powerful the action potential" is false. The strength of the stimulus does not directly determine the power of the action potential. The power of an action potential is determined by the all-or-nothing principle, which states that once the threshold is reached, the action potential is generated at its maximum strength. Therefore, regardless of the strength of the stimulus, the action potential will have the same power.

The synaptic terminal is responsible for relaying signals from one neuron to another neuron or to an effector. It is located at the end of the axon and contains neurotransmitters that are released into the synapse, allowing for communication between neurons.

Reflexes are usually involuntary and rapid because they are produced by the spinal cord and peripheral neurons, bypassing the need for input from the brain. This allows for a quicker response to a stimulus as the signal does not have to travel all the way to the brain for processing. Additionally, reflexes do not involve the integration of sensory input by the interneurons, further contributing to their rapid and automatic nature.

The myelin sheath is a protective covering that surrounds and insulates axons. This insulation allows for faster conduction of nerve impulses compared to axons that are not insulated. The myelin sheath is made up of specialized cells called oligodendrocytes in the central nervous system and Schwann cells in the peripheral nervous system. These cells wrap around the axon, forming multiple layers of myelin that act as an electrical insulator, preventing the loss of electrical signals and increasing the speed at which impulses travel along the axon.

The cerebrum is the largest part of the human brain. It is responsible for higher cognitive functions such as memory, language, reasoning, and problem-solving. It is divided into two hemispheres and contains various lobes that control different functions. The cerebrum plays a crucial role in sensory perception, motor control, and overall intelligence. It is involved in complex processes and is responsible for our conscious thoughts and actions.

The sympathetic division of the nervous system is responsible for the "fight or flight" response, which is activated in times of stress or danger. Nervousness before taking an exam is a common reaction to stress, and it is the sympathetic division that is responsible for this response. This division prepares the body for action by increasing heart rate, dilating pupils, and releasing stress hormones, among other physiological changes. Therefore, the sympathetic division is the part of the nervous system that is responding when experiencing nervousness before taking an exam.

A nerve impulse moves away from a neuron's cell body along axons. Axons are long, slender projections of a neuron that transmit electrical signals away from the cell body towards other neurons, muscles, or glands. Dendrites, on the other hand, receive signals from other neurons and bring them towards the cell body. Nissl bodies are specialized structures within the cell body involved in protein synthesis. Synapses are the junctions between neurons where the transmission of signals occurs. Glia are non-neuronal cells that provide support and insulation to neurons.

The pain-withdrawal reflex involves the transmission of action potentials in the axon of the motor neuron. These action potentials leave the spinal cord through a ventral root and travel in a spinal nerve to a skeletal muscle. This characteristic allows for the quick and automatic withdrawal of a body part from a painful stimulus, helping to protect the body from further harm.

An action potential moves along the axon. The axon is a long, slender projection of a neuron that carries electrical signals away from the cell body to other neurons, muscles, or glands. The myelin sheath, which is a fatty covering around the axon, helps to insulate and speed up the conduction of the action potential. The dendrites receive incoming signals from other neurons, while the synapse is the junction between two neurons where the transmission of signals occurs. The cell body contains the nucleus and other cellular organelles.

When an action potential is conducted along a neuron's axon, the change in charge difference across the membrane spreads from open sodium channels. This change in charge causes sodium channels farther along the axon to open. This allows the action potential to continue propagating down the axon, as the opening of sodium channels leads to the influx of sodium ions, further depolarizing the membrane and triggering the opening of more sodium channels. This positive feedback loop ensures that the action potential is conducted along the entire length of the axon.

The correct answer is interneurons. Interneurons are a type of neuron that form connections between other neurons in the brain and spinal cord. They are responsible for integrating and transmitting signals between sensory and motor neurons, allowing for complex processing and coordination of information. While motor neurons control muscle movement, sensory neurons detect external stimuli, and parasympathetic neurons regulate involuntary bodily functions, interneurons play a crucial role in facilitating communication within the nervous system. Saltatory neurons, on the other hand, do not exist as a distinct category of neurons.

The peripheral nervous system is responsible for connecting the brain and spinal cord with the various systems in the body, including the digestive, respiratory, urinary, reproductive, and circulatory systems. It consists of nerves that extend from the brain and spinal cord to the different parts of the body, allowing for communication and control between the central nervous system and the rest of the body.

Action potentials are electrical impulses that travel along the nerve cell, allowing the synaptic terminals to release neurotransmitters. These neurotransmitters then bind to receptors on another nerve cell, transmitting the signal from one cell to another. This process is crucial for communication between nerve cells and for the transmission of information throughout the nervous system.

During an action potential, sodium ions move into the neuron, causing the inside of the neuron to become positively charged relative to the outside. This is known as depolarization. The movement of sodium ions is followed by the movement of potassium ions out of the neuron, which helps restore the negative charge inside the neuron, known as repolarization. Therefore, the correct answer is that the inside of the neuron becomes positively charged relative to the outside.

The synaptic cleft is the small space between the sending neuron and the receiving neuron. It is the gap where communication between neurons occurs. When an electrical signal reaches the end of the sending neuron, it triggers the release of neurotransmitters into the synaptic cleft. These neurotransmitters then bind to receptors on the receiving neuron, allowing the signal to be transmitted. The synaptic cleft plays a crucial role in the transmission of information between neurons in the nervous system.

The medulla is responsible for controlling vital functions such as breathing and heart rate. It is located in the brainstem and acts as a relay center between the brain and the spinal cord. The medulla contains various nuclei that regulate autonomic functions, including the cardiovascular and respiratory systems. It receives input from sensors throughout the body and sends signals to adjust the heart rate and breathing rate accordingly. Damage to the medulla can lead to life-threatening disruptions in these essential functions.

When an impulse is relayed along a myelinated axon, it "jumps" from one node of Ranvier to another node of Ranvier. The nodes of Ranvier are the small gaps in the myelin sheath where the axon is exposed. These nodes are essential for the rapid conduction of the impulse. The myelin sheath, which is formed by Schwann cells in the peripheral nervous system, insulates the axon and allows for saltatory conduction, where the impulse "jumps" from one node to the next, significantly increasing the speed of transmission. Therefore, the correct answer is "node of Ranvier ... node of Ranvier".

A molecule that carries information across a synaptic cleft is a neurotransmitter. Neurotransmitters are chemical messengers that transmit signals between neurons in the brain and nervous system. They are released by the sending neuron and bind to receptors on the receiving neuron, allowing the transmission of electrical signals and communication between neurons. The other options, such as sending neuron, receiving neuron, synaptic cleft, and synapse, are all components or locations involved in the process of synaptic transmission, but they do not specifically refer to the molecule that carries the information.

The correct answer is that sodium-potassium pumps restore the distribution of ions inside and outside a neuron's membrane following an action potential. These pumps actively transport three sodium ions out of the cell and two potassium ions into the cell, using ATP as a source of energy. This helps to maintain the concentration gradients of sodium and potassium ions across the cell membrane, which is crucial for the proper functioning of neurons and the transmission of nerve impulses.

Addictive drugs such as cocaine, ecstasy, and methamphetamine affect the parts of the brain that use serotonin and dopamine as neurotransmitters. Serotonin is involved in regulating mood, appetite, and sleep, while dopamine is associated with pleasure, reward, and motivation. These drugs increase the levels of serotonin and dopamine in the brain, leading to intense feelings of euphoria and reinforcing the desire to use the drugs again. This can create a cycle of addiction as the brain becomes dependent on the drugs to maintain normal levels of these neurotransmitters.

The parasympathetic division of the autonomic nervous system dominates during times of "rest and digest." This means that it is responsible for promoting relaxation, conserving energy, and facilitating digestion and elimination. It works in opposition to the sympathetic division, which is responsible for the "fight or flight" response.

The three major parts of the brain are the hindbrain, midbrain, and forebrain. The hindbrain is responsible for basic functions such as breathing and heart rate. The midbrain plays a role in sensory processing and movement. The forebrain is the largest part of the brain and is involved in complex functions such as thinking, memory, and emotions.

Schwann cells are responsible for making up the myelin sheath of a motor neuron. The myelin sheath is a protective covering that surrounds the axon of a neuron and helps in the transmission of electrical impulses. Schwann cells are found in the peripheral nervous system and wrap around the axons, forming multiple layers of myelin. This insulation allows for faster and more efficient transmission of signals along the motor neuron, enabling smooth and coordinated movement.

When the voltage-gated sodium channels in a neuron's plasma membrane are opened, sodium rushes into the neuron and diffuses to adjacent areas. This influx of sodium leads to the opening of voltage-gated sodium channels in the adjacent areas. This is because the influx of sodium depolarizes the adjacent areas, causing the voltage-gated sodium channels to open and allow more sodium to enter.

Neurons store neurotransmitter molecules in vesicles located within synaptic terminals. Synaptic terminals are the specialized structures at the ends of the neuron's axon where it forms synapses with other neurons. These vesicles contain neurotransmitters which are released into the synaptic cleft, the small gap between neurons, to transmit signals to the next neuron. The neurotransmitters are stored in vesicles within the synaptic terminals until they are needed for communication between neurons.

The correct answer is "Centralized nervous system". This means that the flatworm has a nervous system where the majority of the nerve cells are concentrated in a specific area, such as the head. This allows for more complex and coordinated responses to stimuli.

When an action potential reaches the end of the axon, it triggers the opening of voltage-regulated calcium channels. This allows calcium ions to enter the neuron. The influx of calcium ions then triggers the release of neurotransmitter molecules from vesicles in the axon terminal into the synaptic cleft. These neurotransmitter molecules can then bind to receptors on the postsynaptic neuron, transmitting the signal across the synapse.

The correct answer is that a neuron transmits information from its dendrites to its synaptic terminals with an electrical signal. This statement accurately describes the process of neuronal communication, where electrical signals generated in the dendrites of a neuron travel along the cell body and axon to reach the synaptic terminals. At the synaptic terminals, the electrical signal is converted into a chemical signal in the form of neurotransmitters, which are released into the synapse to transmit the information to the next neuron.

The nervous system of all mammals is composed of two main parts: the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS consists of the brain and spinal cord, which are responsible for processing and coordinating information. On the other hand, the PNS includes neurons outside of the CNS and the axons that connect them with the CNS. These two parts work together to control and regulate various bodily functions and responses.

The brain determines which neurons are firing action potentials in order to determine what stimulus is stimulating it. When a stimulus is present, specific neurons in the brain become activated and start firing action potentials. By analyzing the patterns and frequency of these firing neurons, the brain is able to identify and interpret the specific stimulus that is being experienced, whether it is light, sound, hunger, or any other sensory input. This process of determining which neurons are firing allows the brain to perceive and understand the world around us.

When a neuron is at its resting potential, there are more potassium ions inside the neuron than outside. This is because the sodium-potassium pumps actively transport potassium ions into the cell while pumping sodium ions out. This creates an imbalance in the distribution of potassium ions, with a higher concentration inside the neuron. This concentration gradient is one of the factors that contribute to the resting potential of the neuron.