The rapid depolarization phase
of myocardial contractile cells is due to the Na+ ions. Sodium ions are essential
for regulation of blood and body fluids, communication of nerve impulses, heart
activity, and metabolic purposes. Physiologically, it survives as an ion in the
body. Sodium is needed by
animals but is not needed by plants. The human prerequisite for sodium<span> must be less
than 500 mg per day. </span>
A Trombe wall (Trombe rhymes with prom, by the way) is a wall that warms trapped air, and then circulates it to help heat a house. Trombe walls are ideally made out of a material with a fairly high thermal mass materials (like bricks or concrete), and are often painted black to improve heat conduction
This change in chromosome number is the result of B. Fertilization. Both of the individual gametes from the male and female combine together to produce a zygote or developing offspring that is diploid in most cases, and possess both sets of genetic content or chromosomal information, one from each parent.