Exhaust system affects fuel efficiency. If you notice you have to fill up your gas tank more often than normal, have your exhaust system checked out by a muffler repair shop. Similar to the vibrations, increased fuel use is a sign something is wrong with your car. When the exhaust leaks, your engine works harder.
Temporal summation is the linear addition of graded potentials that overlap in time; that is, a second potential arrives before the first one from that source has finished. Spatial summation occurs when there is simultaneous arrival of graded potentials originating from more than one synaptic input. Summation occurs at the trigger zone. Typically a multipolar neuron has many active synapses at a given time, with multiple potentials being produced at each.
Best Answer: In humans, most fertilizations occur in the Fallopian tubes. However, sometimes it does happen in the upper uterus. And in other cases -- especially due to pelvic inflammatory disease -- fertilization can occur externally from the reproductive tract, resulting in a seriously ectopic pregnancy.eport Abuse. generally in the Fallopian tubes. Next common place it can occur is in the uterus. It can also occur in the abdomen and when it does, or when the fertilized ovum gets stuck and fails to move down into the uterus, it is called an ectopic pregnancy.