What to look for in a prenatal vitamin. Prenatal vitamins are available by both over-the-counter and by prescription. Although formulations can vary from brand to brand, these are the most important vitamins and minerals to look for:
Muscle pairs. Antagonistic pairs of muscles create movement when one (the prime mover) contracts and the other (the antagonist) relaxes. Examples of antagonistic pairs working are: 1  the quadriceps and hamstrings in the leg.2  the biceps and triceps in the arm.uscle pairs. Antagonistic pairs of muscles create movement when one (the prime mover) contracts and the other (the antagonist) relaxes. Examples of antagonistic pairs working are: 1  the quadriceps and hamstrings in the leg.
4. An agonist ties to a receptor site and causes a response whereas an antagonist works against the drug and blocks the response. 5. Agonists are also chemicals or reactions, which help in binding and also altering the function of the activity of receptors.. Agonist and antagonist act in opposite directions. When agonist produces an action, antagonist opposes the action. 2. Agonist works when the muscles relax and antagonist works when muscles contract.