Immunology Fundamentals Quiz

Immunology Overview

The study of the human immune system is called immunology. This complex network serves several critical functions, including protection from pathogens such as bacteria, viruses, fungi, parasites, cancer cells, and other foreign materials. The immune system also defends against self-destructive processes within our own bodies. It's our body's army fighting off invaders like germs and bacteria.

Immune System Function

At its core, the immune system consists of two main components: innate immunity and adaptive immunity. Innate immunity operates without prior exposure to the antigen and includes physical barriers like skin and mucous membranes; chemical defenses like enzymes and proteins produced by white blood cells; and cellular responses involving phagocytic cells which engulf and digest pathogen particles. Adaptive immunity creates specific recognition of particular antigens through B lymphocytes that produce antibodies and T lymphocytes. These interactions determine what parts of the body need help. When an infection occurs, the body sends out various signals so that cells can respond appropriately. Cells called sensory neurons send messages telling specialized cells where there might be trouble. A group of these cells surrounds the problem area and starts to release chemicals called cytokines. These chemicals tell other cells to come over and make up an army.

Immunodeficiency Disorders

Immune dysfunction can lead to severe conditions referred to as primary immunodeficiencies. Examples range from inherited defects affecting individual organs to generalized immune failure caused by genetic mutations. Secondary immunodeficiencies occur when the normal functioning of the immune system is compromised due to external factors such as age, poor nutrition, medication side effects, illnesses like HIV, or malnutrition.

Immune Response to Infections

When invading microorganisms are detected, immune system cells create a variety of molecules that target them. One type, known as interferons, protects nearby healthy cells while another type, complement proteins, attracts neutrophils—the first line of defense during an infection. Neutrophils are responsible for identifying and attacking any harmful microorganisms they find, all the time communicating with helper cells like T-cells and macrophages to coordinate their attack.

Vaccines and Immunization

Vaccines work because they contain weakened forms of disease-causing organisms, which stimulate your immune system into producing an immune response. They don't cause sickness themselves, but instead teach your immune system to recognize the real thing later. People who get vaccinated don't get sick from the virus used to make the vaccine—and therefore cannot spread it to others.

Autoimmune Diseases

An autoimmune disorder arises when the immune system mistakenly attacks the body itself. There are more than eighty different types of autoimmune diseases, affecting almost every part of the body. Common examples include Type I diabetes, rheumatoid arthritis, multiple sclerosis, and inflammatory bowel syndrome. Treatments aim to reduce swelling and repair damaged tissue, restore organ functions, and prevent further damage and loss of body tissues.