The nervous system communicates through electrical impulses and the communication is very fast. It works in a relay fashion, from point to point comparable to the way the old telephones systems used to work.
The endocrine system communicates by chemical signals via the bloodstream. Hormones are secreted into the blood and extra cellular fluids, then transported to target cells, which must bear a receptor to be able to bind to a specific hormone, and respond.
Hormones are chemical messengers secreted into blood or extracellular fluid that affect the function of other cells.
Endocrine communication is not quite as fast as the nervous system communication
Preventing ph changes caused by the rising and falling pco2 of the plasma
Fertilization is the impregnation, the state when<span> a sperm cell penetrates the egg cell and the genetic material of both cells combines.
A few days after fertilization i</span><span>mplantation happens. Implantation is the attachment of the fertilized egg to the uterus, happens on average about 9 days after ovulation/fertilization (between 6 and 12 days) and is required for the fetus to continue to grow.</span>