How do drugs alter physiological functions?

Drugs alter physiological functions by interacting with the body's biological systems, particularly the nervous and endocrine systems.

Drugs, whether medicinal or recreational, work by interacting with our body's biological systems. They can either mimic the body's natural chemicals, block their actions, or alter their levels. The primary systems that drugs interact with are the nervous system and the endocrine system.

The nervous system is a complex network of nerves and cells that transmit signals between different parts of the body. It includes the central nervous system (brain and spinal cord) and the peripheral nervous system. Drugs can affect the nervous system by altering the way nerve signals are sent, received, and processed. For instance, painkillers like paracetamol work by reducing the production of prostaglandins, substances that sensitise nerve endings, thus reducing pain perception.

The endocrine system, on the other hand, is a collection of glands that produce and secrete hormones, which regulate many bodily functions. Drugs can influence this system by either increasing or decreasing the production of certain hormones. For example, birth control pills contain synthetic hormones that prevent ovulation, thereby preventing pregnancy.

Moreover, drugs can also affect the body's physiological functions by interacting with specific proteins called receptors. These receptors are found on the surface of cells and are responsible for receiving signals from different substances. When a drug binds to a receptor, it can either activate the receptor (agonist), causing a physiological response, or block the receptor (antagonist), preventing a response. For instance, antihistamines are drugs that block histamine receptors, preventing the symptoms of an allergic reaction.

In conclusion, drugs alter physiological functions by interacting with the body's biological systems, particularly the nervous and endocrine systems. They can either mimic the body's natural chemicals, block their actions, or alter their levels. Understanding these interactions is crucial for the development of new drugs and therapies.