Nervous System Homework question n answers graded A+ 2023 passed

Nervous System HomeworkThe period after an initial stimulus when a neuron is not sensitive to another stimulus is the ________. - correct answer absolute refractory period Ions are unequally distributed across the plasma membrane of all cells. This ion distribution creates an electrical potential difference across the membrane. What is the name given to this potential difference? - correct answer Resting membrane potential (RMP) Sodium and potassium ions can diffuse across the plasma membranes of all cells because of the presence of what type of channel? - correct answer Leak channels On average, the resting membrane potential is -70 mV. What does the sign and magnitude of this value tell you? - correct answer The inside surface of the plasma membrane is much more negatively charged than the outside surface. The plasma membrane is much more permeable to K+ than to Na+. Why? - correct answer There are many more K+ leak channels than Na+ leak channels in the plasma membrane. The resting membrane potential depends on two factors that influence the magnitude and direction of Na+ and K+ diffusion across the plasma membrane. Identify these two factors. - correct answer The presence of concentration gradients and leak channels What prevents the Na+ and K+ gradients from dissipating? - correct answer Na+-K+ ATPase Outside of neuron - correct answer postivite inside of neuron - correct answer negative The resting membrane potential is dependent upon two important factors: 1) differences in sodium and potassium concentrations across the membrane (electrochemical gradients) and 2) differences in sodium and potassium membrane permeability. - correct answer - The concentration of K+ is higher inside than outside the cell. - The concentration of Na+ is higher outside than inside the cell. - The membrane is more permeable to K+. - The resting membrane potential is maintained by Na+-K+ pumps that actively transport K+ into and Na+ out of the cell The small space between the sending neuron and the receiving neuron is the - correct answer synaptic cleft A molecule that carries information across a synaptic cleft is a - correct answer neurotransmitter When calcium ions enter the synaptic terminal, - correct answer they cause vesicles containing neurotransmitter molecules to fuse to the plasma membrane of the sending neuron. When neurotransmitter molecules bind to receptors in the plasma membrane of the receiving neuron, - correct answer ion channels in the plasma membrane of the receiving neuron open. If a signal from a sending neuron makes the receiving neuron more negative inside, - correct answer the receiving neuron is less likely to generate an action potential.