1. ) The cell is normally more ___ on the inside and more on the outside. This voltage difference is maintained by the ___. 2. )If enough ions move to exceed the ___, an ___ can be generated that causes a change in the membrane potential big enough to conduct a signal.

is in the form atp or adenosine triphosphate

thrombocytopenia, which is a deficiency in blood platelets, can cause bleeding and bruising in the dermis similar to senile purpura. other possible causes include: exposure to ultraviolet rays and aging skin are common causes of senile purpura. senile purpura may also be a sign of collagen loss in the skin and bones.

several tissues working together form an organ, and several organs together make up an organisms.

the group of cell that carries out special jobs are tissue.