Which body system is considered the MAIN first line of defense against invasion of the body from foreign objects?

A. Endogenous:

Endogenous infections originate from the client's own microbial flora. In this case, the infection was introduced by a procedure in a healthcare setting.

B. Health care-associated:

This urinary tract infection (UTI) developed after hospital admission due to a medical intervention (catheterization), classifying it as a health care-associated infection (HAI), also known as a nosocomial infection.

C. Exogenous:

Exogenous infections are caused by microorganisms from external sources (outside the body). While technically possible, the term HAI is more appropriate in this scenario.

D. Systemic:

A systemic infection affects the entire body (via the bloodstream). A UTI may become systemic if it progresses, but initially, it's a localized HAI.

A. Lymph nodes:

Lymph nodes are structures that filter lymph and house immune cells, but they are not B or T cells themselves.

B. Lymphocytes:

B and T cells are types of lymphocytes, which are white blood cells involved in the immune response.

C. Tonsils:

Tonsils are lymphoid tissue that helps trap pathogens but are not cells.

D. Antibodies:

Antibodies are proteins produced by B cells, not cells themselves.