OCR General Certificate of Secondary Education (GCSE) Biology Practice Exam

How do analgesics, such as paracetamol and ibuprofen, primarily affect nerve impulses?

1. They increase the release of neurotransmitters

2. They block the release of chemicals across the synapse

3. They enhance the transmission of pain signals

4. They create a stronger pain response

The correct answer is: They block the release of chemicals across the synapse

Analgesics like paracetamol and ibuprofen primarily work by blocking the release of chemicals that are responsible for transmitting pain signals within the nervous system. These medications interfere with the inflammatory processes that release pain-inducing substances, such as prostaglandins, thereby reducing the perception of pain. By preventing these chemicals from accumulating and activating pain receptors, analgesics effectively lessen the sensation of pain, allowing for relief without necessarily altering the nerve impulse itself in a traditional sense. The incorrect options typically suggest mechanisms that either amplify pain response or enhance neurotransmitter activity; however, this is contrary to the function of analgesics, which aim to reduce and manage pain effectively.