What is the "all or nothing" component of nerve firings?
An action potential will either fire completely (sending an impulse down the neuron) or not at all.
Which artery carries un-oxygenated blood?
The pulmonary artery – un-oxygenated blood is carried from the right ventricle to the lungs via the pulmonary artery to get oxygenated.
What does a Z-score of 0 mean?
The score falls exactly on the mean.