Basic Physiology Test For Students! MCQ Trivia Quiz

The correct answer is central nervous system & peripheral nervous system. The nervous system is composed of two main parts: the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS includes the brain and spinal cord, which are responsible for processing and coordinating information. The PNS consists of all the nerves outside of the CNS, including sensory nerves that transmit information from the body to the CNS and motor nerves that transmit signals from the CNS to the muscles and glands.

Increasing the number of action potentials, increasing the synthesis of neurotransmitters, and increasing receptors on the postsynaptic membrane all lead to an increase in the transmission of information across the synapse. Antagonists, on the other hand, block or reduce the activity of neurotransmitters, decreasing synaptic transmission.

The action potential amplitude cannot be increased or decreased because of the all or none concept. This concept states that once the threshold is reached, an action potential will occur and its amplitude will be constant, regardless of the strength of the stimulus. This means that the action potential will either fire at full amplitude or not at all, without any variation in between. Therefore, it is not possible to increase or decrease the amplitude of the action potential.

In a typical resting cell, there is an unequal distribution of ions across the cell membrane, which contributes to the electrical potential difference known as the resting membrane potential. Potassium ions (K⁺) have a higher concentration inside the cell, while sodium (Na⁺) and chloride (Cl⁻) ions have higher concentrations outside the cell membrane. This distribution is maintained by active transport mechanisms like the sodium-potassium pump, which helps to maintain the resting membrane potential. Consequently, when considering the ions with a lower concentration outside the cell membrane, potassium is the appropriate choice, as it is primarily found inside the cell.

The correct answer is "All of the above" because acetylcholine, norepinephrine, glycine, and histamine are all types of neurotransmitters. Neurotransmitters are chemical substances that transmit signals between nerve cells in the brain and other parts of the body. Each neurotransmitter has specific functions and is involved in various physiological processes, such as regulating mood, behavior, and cognition. Therefore, all of the listed substances are examples of neurotransmitters.

Salutatory conduction refers to the fast conduction of action potentials in myelinated neurons. This is achieved by the action potential jumping from one node of Ranvier to the next, which allows for a quicker transmission of the signal. This jumping mechanism saves a large quantity of ATP, as the action potential does not have to propagate along the entire length of the axon. Therefore, all of the statements provided are true.

The statement is false because chemical synapses are actually slower than electrical synapses. While neurotransmitters do travel through the synaptic cleft, the process of chemical interaction between regulators and receptors is slower than the movement of ions in electrical synapses. Additionally, the mention of "jap junctions" is likely a typo or error, as it is not a relevant term in this context.

The question asks for a part of a nerve cell that is not included in the given options. The options listed are Axon, Dendrites, Terminals, and Axon hillock. All of these options are actually parts of a nerve cell. Therefore, the correct answer is "None of the above" as none of the given options are excluded from being a part of a nerve cell.

Hormones are chemical messengers that regulate various physiological processes in the body. They can be classified into different types based on their chemical structure. Steroids, proteins, and amines are all types of hormones. However, carbohydrates are not typically classified as hormones. Carbohydrates primarily serve as a source of energy in the body and are not involved in hormonal regulation. Therefore, the correct answer is carbohydrates.

The main contributor to the resting membrane potential is K+ leaky channels. These channels allow the passive movement of K+ ions out of the cell, creating a negative charge inside the cell compared to the outside. This establishes the electrical potential difference across the cell membrane, which is essential for various cellular processes and the transmission of nerve impulses. Na+ voltage gated channels and Na+ stretch channels are involved in the generation and propagation of action potentials, while synapses are sites of communication between neurons and do not directly contribute to the resting membrane potential.

The absolute refractory period refers to the period in which the neuron is unable to generate a second action potential, regardless of the strength of the stimulus. This is due to the fact that during this period, the neuron's voltage-gated sodium channels are inactivated and unable to open, preventing the initiation of another action potential.

The resting membrane potential is the electrical charge difference across the cell membrane when the cell is at rest. It is maintained by the unequal distribution of ions such as K+ and Na+ across the membrane. The correct answer states that the Na+-K+ pump is inhibited, which is wrong. The Na+-K+ pump actively transports Na+ out of the cell and K+ into the cell, contributing to the establishment of the resting membrane potential. If the pump is inhibited, it would disrupt the balance of ions and affect the resting membrane potential.

When the presynaptic membrane of terminals connect to dendrites, the postsynaptic membrane is axodendritic. This means that the connection between the presynaptic terminal and the postsynaptic dendrite is made through the axon of the presynaptic neuron and the dendrite of the postsynaptic neuron. This type of connection is the most common in the nervous system and allows for the transmission of signals between neurons.

The sodium-potassium pump is an active transport mechanism that moves three sodium ions out of the cell and two potassium ions into the cell. This process requires energy in the form of ATP and helps maintain the electrochemical gradient across the cell membrane. By actively transporting sodium out and potassium in, the pump helps establish a negative charge inside the cell and a positive charge outside, which is crucial for various cellular processes such as nerve impulse transmission and muscle contraction.

Action potential is a brief electrical signal that travels along the membrane of a neuron or muscle cell. It is initiated by the opening and closing of ion channels in the membrane, which allows for the rapid movement of ions in and out of the cell. Schwann cells, on the other hand, are responsible for providing insulation and support to the axon of a neuron. They do not generate or propagate action potentials themselves. Therefore, the correct answer is Schwann cells that surround the axon of the neuron.

The membrane is more permeable to K+ than Na+ during all the mentioned phases. This is because the resting potential is maintained by a higher permeability to K+ ions, which allows them to move out of the cell more easily than Na+ ions. During the rising phase of the action potential, the membrane becomes more permeable to Na+ ions, leading to their influx and depolarization of the cell. However, during the falling phase of the action potential, the membrane again becomes more permeable to K+ ions, allowing them to move out of the cell and repolarize it. Therefore, the correct answer is A + C.

Fatigue is a protective mechanism that prevents causing damage to cells. When the body is fatigued, it is a signal that the muscles have reached their limit and need rest to prevent further damage. Fatigue helps to prevent overexertion and injury by signaling the body to slow down or stop before causing harm to the cells and tissues. It is a natural response that allows the body to recover and repair itself, ensuring the overall well-being and functionality of the cells.

Anion channels actually pass negative ions, such as chloride ions (Cl-), because they are lined with positive charges. This allows for the movement of negative ions across the cell membrane.

During the relative refractory period, the membrane is in a state where it is hyperpolarized and requires a stronger stimulus to reach the threshold for an action potential. At resting membrane potential, the membrane is polarized but not actively firing. Therefore, during both the relative refractory period and resting membrane potential, a supra-threshold stimulus can stimulate the membrane and lead to an action potential.

The statement "Is graded responses" is not true about action potential. Action potential is an all-or-nothing response, meaning that once the threshold is reached, it will always result in a full depolarization of the cell membrane. Graded responses, on the other hand, are responses that can vary in magnitude depending on the strength of the stimulus.

Stretch channels do not diffuse Na+ when a neurotransmitter binds to it. Stretch channels are ion channels that open in response to mechanical force or stretch, allowing ions such as Na+ to flow across the cell membrane. They are not directly involved in neurotransmitter binding or diffusion. Therefore, the statement is false.

Raising the pH of the solution can increase conduction velocity in nerves. This is because an increase in pH can lead to a decrease in the concentration of hydrogen ions, which can reduce the positive charge on the membrane and make it more permeable to ions. This increased permeability allows for faster conduction of electrical signals along the nerve.

The default state of Na voltage gated channel is characterized by closed activation gates and open inactivation gates. This means that the channel is not allowing the flow of sodium ions, as the closed activation gates prevent the ions from entering the channel, while the open inactivation gates allow the ions to exit the channel. This state is important for maintaining the resting membrane potential of the cell and preventing the continuous influx of sodium ions.

A bouton refers to the terminal knob on the presynaptic membrane of a neuron. It is a specialized structure involved in the transmission of signals between neurons at a synapse. Therefore, the correct answer is B & C, as boutons are found on both the terminal knobs and the presynaptic membrane.

The role of Ca+2 channels that cause plateau includes depolarizing the membrane, elongating the action potential, and allowing Ca+2 to passively cross inside the membrane. All of these actions contribute to the plateau phase of the action potential.

The given options do not provide an accurate explanation for salutatory potential. Salutatory potential refers to the rapid conduction of action potentials in myelinated nerve fibers, where the signal jumps from one node of Ranvier to another. It is not named point-to-point movement and does not occur in the dendrites of nerves. Additionally, the amount of ATP consumed during salutatory conduction is actually lower compared to continuous conduction. Therefore, the correct answer is "None of the above".

The sinus node is a group of specialized cells located in the right atrium of the heart. These cells are responsible for initiating electrical impulses that regulate the heart's rhythm and coordinate its contractions. Since the sinus node is part of the heart and not the brain, it cannot be found in the brain. Additionally, the sinus node consists of muscle fibers rather than nerve fibers, as it is responsible for generating and conducting electrical signals within the heart muscle.

The repulsion force stops K+ from moving outside the membrane. This force occurs due to the presence of other positive ions inside the membrane, including K+ itself. Like charges repel each other, so the positive charges of K+ are repelled by the positive charges of the other ions. This repulsion force prevents K+ from moving outside the membrane and keeps it confined within the cell.

The correct answer is "None of the above." None of the given options would increase the excitability of the cell membrane. Opening chloride ion channels would actually inhibit the cell, increasing the conductance of K+ would hyperpolarize the cell and decrease its excitability, decreasing excitatory membrane receptors would also decrease excitability, and increasing the activity of the sodium-potassium pump would not directly affect cell excitability. Therefore, none of the options listed would increase the excitability of the cell membrane.

When the G protein is separated from the β and γ components and connected to ATP or GTP, it becomes activated. This is because the binding of ATP or GTP allows the G protein to undergo a conformational change, enabling it to interact with other signaling molecules and initiate downstream signaling pathways. The separation from the β and γ components is necessary for the G protein to function independently and carry out its signaling role.