Problem 5 - Anatomy and Physiology of Animals

Question

Watch this video (http://openstaxcollege.org/I/ rheuarthritis) to learn about the symptoms and treatments for rheumatoid arthritis. Which system of the body malfunctions in rheumatoid arthritis and what does this cause?

Step-by-Step Solution

Answer

The immune system malfunctions, causing joint inflammation and pain.

Step 1: Understand Rheumatoid Arthritis

Rheumatoid arthritis is an autoimmune disorder, which means it's a condition where the body's immune system mistakenly attacks its own tissues.

Step 2: Identify Affected System

In rheumatoid arthritis, the autoimmune attack primarily targets the musculoskeletal system, particularly the joints, leading to inflammation, pain, and eventually joint damage.

Step 3: Understand the Malfunction

The immune system, which usually protects the body from infections and diseases, malfunctions by sending antibodies to the lining of the joints, causing inflammation.

Step 4: Consequences of Malfunction

This malfunction causes symptoms such as joint pain, swelling, stiffness, and potential loss of joint function. If left untreated, it can lead to joint deformities and bone erosion.

Key Concepts

Immune System Malfunction

In the human body, the immune system plays a critical role in defending us against harmful invaders like bacteria and viruses. However, sometimes this protective mechanism goes awry. A prime example is rheumatoid arthritis. Here, the immune system malfunctions by mistakenly identifying the body's own joint tissues as threats. Instead of safeguarding the body, it attacks these tissues. This error occurs because the immune system sends out antibodies that specifically target the lining of joints. This incorrect targeting is the foundation of many issues that arise in rheumatoid arthritis, setting off a cascade of painful symptoms.

Inflammation and Pain

When the immune system attacks joint tissue, inflammation occurs as a natural response to what it believes is an injury. Inflammation is marked by swelling, redness, and warmth in affected areas. This is common in any part of the body trying to heal from perceived harm. However, in rheumatoid arthritis, this inflammation is chronic. It does not go away like it would in a typical injury healing process. This constant inflammation leads to persistent pain in the joints. Over time, repetitive cycles of inflammation can wear down tissue, making it difficult for individuals to perform everyday activities without discomfort.

Joint Damage

The chronic inflammation caused by rheumatoid arthritis goes beyond just causing pain. It can lead to significant joint damage over time. When inflammation remains unchecked, it begins to erode cartilage and bone within the joints. Erosion of cartilage, which cushions the joints, causes the bones to grind against each other. This not only increases pain but also reduces joint mobility. The persistent immune attack can result in deformities of the joints too, leading to a visible and functional decline. Without proper treatment, joint damage can be irreversible, highlighting the need for early intervention.

Autoimmune Disorder

Rheumatoid arthritis is categorized as an autoimmune disorder, which is a broader class of diseases where the immune system mistakenly attacks the body's own cells. In autoimmune disorders, the immune system loses its ability to distinguish between foreign invaders and healthy tissue. This misidentification leads to the immune system attacking its own body's cells. Other examples of autoimmune disorders include lupus, multiple sclerosis, and type 1 diabetes. Understanding rheumatoid arthritis as an autoimmune disorder helps in comprehending the nature of the disease and its potential impact on the body, emphasizing the importance of careful management and treatment plans.