What components make up the human immune system?

Organs, tissues, cells, and antibodies

a) Organs, tissues, cells, and antibodies

The human immune system is composed of various components that work together to defend the body against pathogens and foreign substances. These components include organs, tissues, cells, and antibodies.

Organs: The immune system includes primary lymphoid organs, such as the bone marrow and thymus, where immune cells mature and develop. It also includes secondary lymphoid organs, such as the spleen and lymph nodes, where immune responses are initiated.

Tissues: Lymphoid tissues are present throughout the body and play a role in immune responses. Examples include the lymphoid nodules in the mucosal lining of the respiratory and gastrointestinal tracts.

Cells: Immune cells are crucial for the functioning of the immune system. They include white blood cells, such as lymphocytes (B cells and T cells), macrophages, neutrophils, and dendritic cells. Each type of immune cell has specific functions in detecting, capturing, and eliminating pathogens or abnormal cells.

Antibodies: Antibodies, also known as immunoglobulins, are proteins produced by B cells in response to specific antigens. Antibodies help to neutralize pathogens, mark them for destruction, and assist in the immune response.

While blood, bones, muscles (option b), nerves, hormones, and enzymes (option c) are important components of the human body, they are not the specific components that make up the immune system. Proteins, carbohydrates, and lipids (option d) are essential molecules found in the body but do not represent the components of the immune system.