Answer:
Cytotoxic T cell
Helper T cell
Explanation:
Adaptive immune system is a part of the immune system initiated only when there is an attack by a pathogen or foreign substance. The adaptive immune system is beckoned on when the infection is insurmountable for the body's first line of immunity, which is the innate immune system.
The adaptive immune response is triggered by the white blood cells called LYMPHOCYTES. Lymphocytes consists of T cells and B cells. T cells are either cytotoxic or helper T cells. The cytotoxic T cells kills the cells infected with the virus while the Helper T cells activate every other cell involved in the immune process.
It's caused by blood pooling in the legs, so there's insufficient return to the heart and brain. Normally, moving one's legs helps to pump blood back to the heart through muscle contraction. Locking the knees makes standing still easier, but reduces use of the leg muscles. In some people, this pooling may lead to hypoperfusion of the brain and fainting, which is essentially the body's way of putting the brain and the legs and the heart at the same level.
The answer is C: Sperm cell
