<span>The frontal and parietal bones of the skull are susceptible to compressed skull fractures. This is especially important in newborn babies. There is a location in the skull called the Anterior Fontanelle, where two frontal and 2 parietal bones meet. This area of the skull is very soft until as late as 2 years old.</span>
It is called ACCOMMODATION. Accommodation refers to the mechanism by which the eye adjusts his optical power in order to focus properly on an object as the distance of the object varies. To achieve this, the shape of the lens has to be adjusted appropriately.
An area in the South region Babylonian in present - day Iraq
The chief City of ancient Mesopotamia and capital of the ancient kingdom of Babylonia
<span>The kidneys are retroperitoneal (towards the back) high in the dorsal body wall both in humans and cats.</span>
Answer:
Helper T cells stimulate B-cells to produce antibodies and killer T cells to destroy the non-self cells. Cytotoxic T cells on the other hand are direct attack cells. They can kill the micro organisms by creating pores on the invader's cell.
Explanation:
T lymphocyte mediated immunity of cell mediated immunity do not secrete antibodies but they help stimulate the B cells to produce them. Immature T cells are produced in bone marrow from where they migrate to thymus via blood. In the thymus maturation of T cells occur and then they migrate to lymphoid tissue and get differentiated into three types:
a. Helper T cells: As the name suggests, they help in activating other immune cells, in other terms they are the regulator of virtually all functions of immune system. Protein mediator called lymphokines are produced by these helper T cells in order to regulate the immune functions. Some examples of these lymphokines are: Interleukin-2 interleukin-3, interferon gamma. T helper cells stimulate the B-cells to produce antibodies.
b. Cytotoxic cells or killer T cells: The lymphokine interleukin-2 is responsible for the growth and proliferation of both cytotoxic T cells and suppressor T cells. With the help of receptor proteins on the surface of killer T cells, they bind to the specific antigen. After binding, they secrete a pore forming protein called perforins which create pores on the invaders cell membrane for water to enter into it thereby cell swells and finally lyse.
c. Suppressor T cells: They suppress the function of above two T cells.
