Test You Knowledge On Bio Science With This Quiz!

Afferent neurons are specialized to detect stimuli and send signals to the central nervous system, while efferent neurons send signals from the central nervous system to the effectors of the nervous system, such as muscles or glands. Therefore, the correct answer is "afferent; efferent".

The correct answer is acetycholine. A cholinergic synapse refers to a synapse that uses acetylcholine as its neurotransmitter. Acetylcholine is a type of neurotransmitter that is involved in various functions in the body, including muscle movement, memory, and learning. It is released from the presynaptic neuron and binds to receptors on the postsynaptic neuron, transmitting the signal across the synapse. Other options such as epinephrine, monoamine, norepinephrine, and catecholamine are not typically associated with cholinergic synapses.

Dendrites are the primary site for receiving signals from other neurons. They are the branch-like extensions of a neuron that receive electrical impulses and neurotransmitters from other neurons. These signals are then transmitted to the soma, or cell body, of the neuron where they are integrated and processed. Dendrites play a crucial role in the communication between neurons, as they receive and transmit information, allowing for the transmission of signals throughout the nervous system.

The myelin sheath, which is a protective covering around nerve fibers, is primarily composed of lipids. Lipids are a type of organic molecule that includes fats, oils, and waxes. They are nonpolar and hydrophobic, meaning they repel water. This property is important for the myelin sheath as it helps insulate and protect the nerve fibers. Lipids also provide structural support and help maintain the integrity of the myelin sheath.

A multipolar neuron is the most common type of neuron. This type of neuron has multiple processes extending from its cell body, with one axon and multiple dendrites. The axon carries signals away from the cell body, while the dendrites receive signals from other neurons. This structural arrangement allows multipolar neurons to integrate and transmit information efficiently. They are found in the brain and spinal cord, where they play a crucial role in processing and transmitting nerve impulses.

The sympathetic division of the autonomic nervous system is responsible for preparing the body for action. It is commonly referred to as the "fight or flight" response, as it activates various physiological responses to help the body respond to perceived threats or stressful situations. These responses include increased heart rate, elevated blood pressure, dilation of the pupils, and release of adrenaline.

The conduction speed of a nerve fiber is determined by the presence of myelin, which acts as an insulating layer around the fiber. Myelin increases the speed of conduction by allowing the electrical signal to "jump" from one node of Ranvier to the next, rather than having to travel along the entire length of the fiber. Therefore, the larger the myelinated fiber, the faster the conduction speed will be.

When the sodium gates open, it allows sodium ions to enter the cell, causing a change in the distribution of charges across the plasma membrane. This influx of positive sodium ions leads to a decrease in the negative charge inside the cell, resulting in depolarization of the plasma membrane.

Neurotransmitters are chemical messengers that transmit signals between neurons. They are typically released in response to stimulation, synthesized by a presynaptic neuron, bind to specific receptors on the postsynaptic cell, and alter the physiology of the postsynaptic cell. However, neurotransmitters are not released into the bloodstream before reaching the postsynaptic cell. Instead, they are released into the synaptic cleft, the small gap between the presynaptic and postsynaptic cells, where they can bind to receptors on the postsynaptic cell and transmit the signal.

Oligodendrocytes are a type of glial cell found in the central nervous system (CNS). They are responsible for producing myelin, a fatty substance that forms a protective covering around nerve fibers in the spinal cord and brain. This myelin sheath helps to insulate and increase the speed of nerve impulse transmission. Oligodendrocytes are unique in their ability to form multiple segments of myelin along different nerve fibers, allowing for efficient communication within the CNS. Unlike Schwann cells, which perform a similar function in the peripheral nervous system, oligodendrocytes can myelinate multiple nerve fibers at once.

Local potentials are graded, meaning that the strength of the signal can vary depending on the stimulus intensity. They can be either excitatory or inhibitory and can summate to reach the threshold for an action potential. On the other hand, action potentials are all or none, meaning that they either occur fully or do not occur at all. Once the threshold is reached, an action potential is generated and it propagates along the neuron without decreasing in strength. Therefore, the correct answer is "graded; all or none".

Potassium has the greatest influence on the resting membrane potential because it is the main ion involved in establishing the resting membrane potential. The resting membrane potential is the electrical charge difference across the cell membrane when the cell is at rest. Potassium ions are more concentrated inside the cell than outside, and the cell membrane is more permeable to potassium than any other ion. This creates a negative charge inside the cell, making the resting membrane potential primarily determined by potassium ions.

During the absolute refractory period, the neuron is temporarily unresponsive to any stimulus, regardless of its strength. This is because the voltage-gated sodium channels that are responsible for generating the action potential are inactivated and cannot be opened. Therefore, even if a stimulus is applied, it will not be able to trigger a new action potential until the refractory period is over and the channels have returned to their resting state.

The correct answer is Visceral motor. The visceral motor division of the autonomic nervous system controls the involuntary movements of smooth muscle in organs such as the large intestine. This division carries signals from the central nervous system to the smooth muscle, allowing for the regulation of functions such as digestion and elimination.

Glands are examples of effectors in the nervous system because they are responsible for producing and releasing hormones in response to signals from the nervous system. Effectors are the structures or organs that carry out the response to a stimulus, and glands play a crucial role in maintaining homeostasis and regulating various bodily functions through hormone secretion.

When the membrane is depolarizing, the sodium gates are fully open. This means that the channels for sodium ions in the cell membrane are fully open, allowing a large influx of sodium ions into the cell. This influx of positive sodium ions helps to further depolarize the membrane, leading to the generation of an action potential.

Nerve fibers refer to axons, which are long, slender projections of nerve cells that transmit electrical impulses. Axons are responsible for carrying information from one part of the body to another, allowing for communication between different cells and tissues.

The autonomic nervous system is responsible for regulating involuntary bodily functions such as heart rate, digestion, and breathing. It is divided into two main divisions: the sympathetic division and the parasympathetic division. The sympathetic division prepares the body for "fight or flight" responses, while the parasympathetic division promotes relaxation and "rest and digest" activities. The visceral motor division refers to the autonomic nervous system as a whole, encompassing both the sympathetic and parasympathetic divisions.

The soma, also known as the cell body, is the main part of a neuron where most metabolic and regulatory functions occur. It contains the nucleus and other organelles necessary for the neuron's functioning. The axon and dendrites are extensions of the soma that transmit and receive signals, respectively. Schwann cells are responsible for myelinating axons in the peripheral nervous system. The axon hillock is the region where the axon originates from the soma. However, the soma is where the majority of metabolic and regulatory processes take place in a neuron.

Parkinson's disease is caused by the degeneration of dopamine-producing neurons in the brain. Dopamine is an inhibitory neurotransmitter that helps regulate movement and coordination. When these neurons die, there is a deficiency of dopamine, leading to the loss of motor function seen in Parkinson's disease. Therefore, the correct answer is dopamine.

The correct answer is "association." Association neurons, also known as interneurons, are responsible for connecting sensory and motor neurons. They receive information from sensory neurons and transmit it to motor neurons, allowing for the coordination of movement and the processing of sensory information. These neurons play a crucial role in integrating and interpreting signals within the nervous system.

The question is incomplete and does not provide enough information to determine the correct answer. The given answer options are unrelated to the question and do not provide any explanation for why GABA is the correct answer.

Some antidepressant drugs act by inhibiting monoamine oxidase (MAO), which is an enzyme that breaks down monoamines. Monoamines are neurotransmitters such as serotonin, dopamine, and norepinephrine that play a role in regulating mood. By inhibiting the breakdown of monoamines, these drugs increase their availability in the brain, which can help alleviate symptoms of depression.

When the voltage of a plasma membrane shifts from +35mV towards 0 mV, we say the cell is repolarizing. Repolarization refers to the process of restoring the membrane potential back to its resting state after depolarization. In this case, the cell is moving away from a positive charge and returning to a more negative charge, which indicates repolarization.

Acetylcholine is a neurotransmitter that has different effects on different muscles. In this case, it excites skeletal muscle, meaning it stimulates the contraction of skeletal muscle fibers. On the other hand, acetylcholine inhibits cardiac muscle, meaning it decreases the rate and force of contraction of the heart. Therefore, acetylcholine has opposite effects on skeletal and cardiac muscles.

For a peripheral nerve fiber to regenerate, it requires the soma (cell body) to be intact, as well as at least some of the neurilemma (the outer layer of the axon). The soma contains the nucleus and other essential components for cellular functioning, while the neurilemma provides the necessary guidance and support for axon regrowth. Therefore, both the soma and neurilemma are crucial for nerve fiber regeneration.

The myelin sheath, a protective covering around nerve fibers, is formed by cells. These cells are called oligodendrocytes in the central nervous system and Schwann cells in the peripheral nervous system. These specialized cells wrap around the nerve fibers, creating multiple layers of cell membrane that form the myelin sheath. The myelin sheath helps to insulate and protect the nerve fibers, allowing for faster and more efficient transmission of electrical signals along the nerves.

An inhibitory local potential hyperpolarizes the plasma membrane. When an inhibitory signal is received by a neuron, it increases the permeability of the membrane to negatively charged ions, such as chloride ions. This causes an influx of these ions into the cell, making the inside of the cell more negative compared to the outside. As a result, the membrane potential becomes more negative, leading to hyperpolarization. This makes it more difficult for the neuron to generate an action potential and transmit signals.

A reverberating circuit is the best type of neural pool for producing a prolonged output because it consists of a feedback loop where the output of the circuit is sent back into the circuit, causing it to continue firing and producing output signals for an extended period of time. This continuous feedback loop allows for sustained activity and prolonged output in the neural pool.

An EPSP (excitatory postsynaptic potential) is a voltage change that makes a neuron more likely to fire an action potential. In this case, the voltage change from -70 mV to -69.5 mV is an example of an EPSP because it is a depolarization, meaning the neuron's membrane potential becomes less negative. This depolarization brings the neuron closer to the threshold for firing an action potential, increasing the likelihood of neuronal activation.

Presynaptic inhibition is the opposite of facilitation because facilitation refers to the process of increasing the strength of synaptic transmission, while presynaptic inhibition refers to the process of decreasing the strength of synaptic transmission. In facilitation, the presynaptic neuron releases more neurotransmitters, leading to an enhanced response in the postsynaptic neuron. On the other hand, presynaptic inhibition involves the release of inhibitory neurotransmitters, which reduces the amount of neurotransmitters released by the presynaptic neuron, resulting in a weaker response in the postsynaptic neuron.

The inflow of chloride ions will cause the plasma membrane to hyperpolarize when at its resting membrane potential (RMP). Hyperpolarization refers to an increase in the membrane potential, making it more negative than the RMP. Since chloride ions carry a negative charge, their influx will further increase the negativity inside the cell, leading to hyperpolarization. In contrast, the inflow of sodium, potassium, or calcium ions would depolarize the membrane, while the outflow of chloride ions would also tend to depolarize the membrane.

This answer is correct because the neurotransmitter mentioned in the statement, which is the most common inhibitory neurotransmitter in the brain, binds to ligand-regulated gates. When it binds, it causes hyperpolarization of the cell membrane. Hyperpolarization refers to an increase in the negative charge inside the cell, making it less likely for the neuron to fire an action potential and therefore inhibiting the transmission of signals.

Local potentials are small changes in the electrical charge of a neuron that occur in response to the stimulation of dendrites. Dendrites are the branch-like structures that receive incoming signals from other neurons and transmit them towards the soma (cell body) of the neuron. These local potentials are graded, meaning their magnitude can vary depending on the strength of the stimulus. Therefore, the correct answer is dendrites, as they are responsible for the initiation of local potentials in the neuron.

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A traveling wave of excitation refers to the transmission of electrical impulses along a nerve fiber. These impulses, known as nerve signals, are responsible for transmitting information throughout the nervous system. They are generated through a series of depolarizing signals, which cause a change in the electrical potential of the nerve cell. This change in potential, also known as a local or graded potential, eventually leads to the generation of an action potential, which is the actual nerve signal that travels along the nerve fiber.

Spatial summation refers to the process in which a neuron integrates the EPSPs (excitatory postsynaptic potentials) from different synapses located at different spatial locations on its dendrites. If the combined EPSPs reach the threshold, the neuron will generate an action potential. This process allows the neuron to sum up the effects of multiple synapses and determine whether to fire or not based on the spatial distribution of inputs.

In an adrenergic synaptic transmission, the G protein dissociates from the NE receptor first. This dissociation occurs when norepinephrine (NE) binds to the adrenergic receptor, causing a conformational change that leads to the dissociation of the G protein from the receptor. This dissociation allows the G protein to interact with other molecules involved in the signaling pathway, such as adenylate cyclase, which is activated subsequently. The activation of adenylate cyclase leads to the conversion of ATP to cyclic AMP, which then induces several effects in the cell.

Synaptic vesicles secrete neurotransmitters by exocytosis, which is a crucial step in synaptic transmission. This process involves the release of neurotransmitters from the presynaptic neuron into the synaptic cleft, allowing them to bind to receptors on the postsynaptic neuron and transmit the signal. The other options listed all contribute to the cessation of the signal in synaptic transmission. The synaptic knob reabsorbs some neurotransmitters by endocytosis, neurotransmitters stop being released, neurotransmitters escape from the synapse into the nearby extracellular fluid, and enzymes in the postsynaptic cell break down some neurotransmitters, all contribute to the termination of the signal transmission.

Nerves are a part of the nervous system, which is responsible for transmitting signals throughout the body. Organs, such as the brain and spinal cord, are key components of the nervous system, and nerves are the specialized cells that make up these organs. Therefore, the correct answer is "organs."

During hyperpolarization, the membrane potential becomes more negative than the resting membrane potential. This occurs due to the efflux of potassium ions out of the cell. As potassium channels open, the concentration gradient for potassium drives these ions out of the cell, causing the membrane potential to become more negative. This efflux of potassium ions is responsible for the repolarization phase of the action potential, allowing the cell to return to its resting state. Therefore, the correct answer is that potassium ions are leaving the cell during hyperpolarization.

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In a cholinergic synaptic transmission, the first event to occur is the release of ACh from the synaptic vesicles. This is followed by ACh diffusing across the synaptic cleft, binding to ligand-regulated gates, and producing a postsynaptic potential. Finally, sodium enters the postsynaptic cell.

The correct answer is "diffusion of ions along the axoplasm is faster." In myelinated fibers, the axons are covered with a fatty substance called myelin, which acts as an insulator. This insulation prevents the ions from diffusing out of the axoplasm and forces them to travel through the nodes of Ranvier, where the myelin is absent. This jumping of ions from one node to another allows for faster conduction of signals. In unmyelinated fibers, there is no myelin covering, so diffusion of ions occurs along the entire axoplasm, resulting in slower signal conduction.

Local potentials are decremental, meaning they decrease in magnitude as they spread away from the site of stimulation. This is because the strength of the stimulus diminishes as it travels along the neuron. Local potentials are not all-or-nothing like action potentials, but rather their size is directly proportional to the strength of the stimulus.

Coding refers to the process by which information is represented and transmitted in the nervous system. Inhibitory postsynaptic potentials (IPSPs) are associated with hyperpolarization of the cell membrane, which decreases the likelihood of the neuron firing an action potential. This change in membrane potential is a form of information coding, as it represents the inhibitory input received by the neuron. Therefore, the correct answer is coding.