That answer you may be looking for is neurohormones, Which are producesd by specialized cells in the brain and travel through the blood stream to affect cells throughout distant parts of the body.
NEUROHORMONES
Hormones
Hormones of the endocrine glands.
neurohormones
Hormones
I suppose that you think to oxygen.Oxygen is indispensable for life.
it can move through the bloodstream quickly. Only 12 hours after entering the bloodstream, Borrelia burgdorferi can be found in cerebrospinal fluid (which means it can affect the nervous system
Infections of the teeth and gums, CAN spread to the Heart through the Bloodstream. So, yes, it can effect the heart valves.
The mothers bloodstream then contains alcohol and that makes its way to the unborn fetus through blood and the umbilical chord.
The traditional approach is that human and animal hormones are produced in endocrine glands, which release them directly into blood, and the bloodstream carries them to their target cells. However, it doesn't necessarily have to be blood, it can be tissue fluid as well. (And not all organisms that have hormones have blood either. In plants for example, hormones can migrate to other cells from the site of production through the plasmodesmata that connect neighboring cells.)
pituitary gland .
Yes. Hormones are transported throughout the body, via the bloodstream. They do not, however, effect every cell. Only certain cells in the body have the proper receptor sites to accomodate hormones. Therefore, even though hormones are transported right through the body, they only create a reaction for certain things.