Final answer:
Prostaglandins are unsaturated fatty acids with a variety of physiological roles, including the regulation of inflammation and blood clotting. They are produced from arachidonic acid and act as local hormones with short-lived actions within the body.
Step-by-step explanation:
Prostaglandins are chemical messengers that contain a five-membered ring and have a wide range of biological activities. They are responsible for various physiological processes, including blood pressure regulation, inflammation, blood clotting, gastric secretions, kidney functions, and reproductive activities. Prostaglandins are derived from arachidonic acid, a polyunsaturated fatty acid, and are considered an unsaturated fatty acid containing 20 carbon atoms. They act at the site where they are produced and are quickly metabolized, which is why they are classified as local hormones or autocrine and paracrine signaling molecules. Aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) work by inhibiting the synthesis of prostaglandins, which can modulate pain and inflammation responses.