Muscle and nerve tissue and physiology: Neurons and muscle cells have much in common, in that they both are excitable, conduct electric impulses by allowing sodium ions to enter and potassium ions to exit, and both function by allowing calcium ions to move back and forth across membranes.&P I Muscle Physiology. Compare the connective tissue coverings of the muscles with those of the nerves. The extensions of epimysium, perimysium, and endomysium into tendons are called epitendinium, etc. Nerves also contain fascicles (fasciculi), which are covered by perineurium, and contain neurons.