How do beta-blockers work? What exactly do antibiotics do to the bacteria they target? What effects does an anti-depressant have on blood flow?

Advanced pharmacology Dssion and Assignment

They work by blocking the effect of epinephrine. Epinephrine is a hormone which increases blood pressure. They specifically block β-adrenergic receptors in the body, which are found in the brain, lungs, heart and other organs. These receptors are blocked by beta blockers, which reduces symptoms of high epinephrine levels, such as anxiety and chest pain.
In order to work, antibiotics target bacteria and stop them reproducing. They also prevent the production of essential cell components that are needed for growth. Certain antibiotics can target bacteria’s cell walls or proteins to prevent growth while others interfere with nucleic acid synthesis or cell metabolism.
Serotonin, a neurotransmitter that is produced by anti-depressants, increases their levels and helps to balance the mood. Researchers have shown that antidepressants may also affect the blood flow of certain parts of the brain, where serotonin can be produced. The increased activity seems to link to better cognitive function and emotional health.