Ch. 4 Fundamentals of Human Neuropsychology
Multiple Sclerosis - correct answer The degenerative disease attacks protective myelin covering of axons,
causing inflammation and often destroying the myelin in patches. Eventually a hard scar of plaque, may
form in the affected areas. Which is why the disease is called sclerosis (from the Greek word meaning
"hardness") when plaque forms, the usual flow of nerve impulses along axons is distorted.
Saltaory Conduction - correct answer These tiny gaps in the myelin sheath are sufficiently close close to
one another that an action potential at one node can trigger voltage-sensitive gates to open at an
adjacent node. In this way action potential jumps from node to node. Thus flow of energy is called
saltatory conduction (from the latin verb saltare meaning "to leap").
Cations/ anions - correct answer The intracellular and extracellular fluids of a neuron are filled with
positively charged ions (cations) of both sodium Na+ and Potassium k+, as well as negatively charged
(anions) (A-) of chlorine, Cl-, or chloride ions.
Voltage Gradient - correct answer The difference in charge between two regions that allow a flow of
current if the two regions are connected. The voltage gradient allows for measuring the relative
concentrations of positive and negative electrical charges in the current across the cell membrane.
Concentration Gradient - correct answer When the substance is not evenly dispersed, the term
concentration gradient describes the relative difference in the amount of a substance at different
locations in a container.
Three factors influence the movement of ions into and out of cells - correct answer 1. A concentration
gradient
2. Voltage Gradient
3. Cell Membrane Structure
Exocytosis - correct answer Proteins destined to be excreted, a process called exocitosis, remain within
their membranes, which fuse with the cell membrane, allowing the protein to be expelled into the
extracellular fluid, perhaps as a neurotransmitter carrying a message to another neuron.
Three categories of membrane proteins that assist in transporting substances across the membrane -
correct answer 1. Channels: Some membrane proteins are shaped in such a way that they create
channels, or holes, through which substances can pass.
2. Gates: An important feature of some protein molecules is their ability to change shape.
Multiple Sclerosis - correct answer The degenerative disease attacks protective myelin covering of axons,
causing inflammation and often destroying the myelin in patches. Eventually a hard scar of plaque, may
form in the affected areas. Which is why the disease is called sclerosis (from the Greek word meaning
"hardness") when plaque forms, the usual flow of nerve impulses along axons is distorted.
Saltaory Conduction - correct answer These tiny gaps in the myelin sheath are sufficiently close close to
one another that an action potential at one node can trigger voltage-sensitive gates to open at an
adjacent node. In this way action potential jumps from node to node. Thus flow of energy is called
saltatory conduction (from the latin verb saltare meaning "to leap").
Cations/ anions - correct answer The intracellular and extracellular fluids of a neuron are filled with
positively charged ions (cations) of both sodium Na+ and Potassium k+, as well as negatively charged
(anions) (A-) of chlorine, Cl-, or chloride ions.
Voltage Gradient - correct answer The difference in charge between two regions that allow a flow of
current if the two regions are connected. The voltage gradient allows for measuring the relative
concentrations of positive and negative electrical charges in the current across the cell membrane.
Concentration Gradient - correct answer When the substance is not evenly dispersed, the term
concentration gradient describes the relative difference in the amount of a substance at different
locations in a container.
Three factors influence the movement of ions into and out of cells - correct answer 1. A concentration
gradient
2. Voltage Gradient
3. Cell Membrane Structure
Exocytosis - correct answer Proteins destined to be excreted, a process called exocitosis, remain within
their membranes, which fuse with the cell membrane, allowing the protein to be expelled into the
extracellular fluid, perhaps as a neurotransmitter carrying a message to another neuron.
Three categories of membrane proteins that assist in transporting substances across the membrane -
correct answer 1. Channels: Some membrane proteins are shaped in such a way that they create
channels, or holes, through which substances can pass.
2. Gates: An important feature of some protein molecules is their ability to change shape.
