Question

Which components of the human immune response explain why we experience the same symptoms of an upper respiratory infection (a "cold") when many different types of viruses can cause these conditions?

Short answer

The consistent cold symptoms we experience, despite the variety of viruses, result from our immune system's general response to viral invaders. Both the innate and adaptive immune responses result in the symptoms we associate with a cold, such as stuffy nose, cough, and fever. Regardless of the specific virus, these immune responses produce similar symptoms due to general defensive mechanisms, not due to the virus specific factors.

Step-by-step solution

Identifying the Components of the Immune Response

The human immune response is quite complex and involves a number of different systems. In relation to a cold, the innate and adaptive immune responses are the most relevant.

Understanding Innate Immune Response

The innate immune response involves components like the inflammatory response and the release of cytokines. When a pathogen (such as a cold virus) invades the body, these responses are activated quite quickly. The inflammation helps to slow the spread of the pathogen at the initial site of infection and cytokines signal the immune system to react.

Connecting Innate Immune Response to Symptoms

The activation of the inflammatory response and cytokines causes common symptoms such as a runny nose, congestion, and body aches.

Adaptive Immune Response

The adaptive immune response involves components like T cells and B cells. T cells identify infected cells and orchestrate their destruction whereas B cells produce antibodies specific to the virus.

Linking Adaptive Immune Response to Symptoms

The adaptive response takes longer to kick in, as the immune system needs to identify the specific pathogen and plan its attack. The process can induce fatigue and fever, and as the immune system steps up to combat the virus and destroy infected cells, coughing and other symptoms may worsen.

Understanding Similarity in Cold Symptoms

Despite there being numerous different viruses that can cause a cold, the body's immune response to these pathogens is similar. This is because the immune system treats all invading viruses in an alike manner, initiating the same type of immune responses and producing similar symptoms.