Semen by definition is the fluid ejaculated from a male, which includes the sperm cells as well as a number of other components. The Elements (ingredients) Of Semen. Very simply put, seminal fluid is a thick white secretion rich in sugars, mostly fructose to fuel the sperm cells on their journey to the egg. This secretion is what composes the bulk of semen by volume (50-80%). Although mostly comprised of water, proteins, and sugars.
The T-cell receptor, or TCR, is a molecule found on the surface of T cells, or T lymphocytes, that is responsible for recognizing fragments of antigen as peptides bound to major histocompatibility complex (MHC) molecules.
A answered. Lymphocytes are different from other types of white blood cells because they recognize and remember invading bacteria and viruses. T lymphocytes, or T cells, are responsible for cell-mediated immunity. T cells come in many types with specific functions, including: Helper T cells direct the immune system. In a rather lengthy process, helper T cells release cytokines. Cytokines stimulate B cells to form plasma cells. Plasma cells form antibodies, which stimulate the production of two other types of T cells: cytotoxic T cells and suppressor T cells. Helper T cells are the cells attacked by the AIDS virus. You can imagine the devastating effect of destroying the T cells that direct the immune system. Cytotoxic T cells release certain chemicals that break open to kill invading organisms.