Immune System Functions and Antibodies Lecture

Flashcards testing knowledge on body defense mechanisms, antibody classes, phagocytes, and immunity types based on the lecture notes.

How does the structural organization of the immune system differ from other body systems?

Unlike other body systems, the immune system is not contained within a single site of organs or vessels, but instead uses structures in several other body systems.

What characteristics make intact skin an effective first line of defense against invading organisms?

Intact skin wraps the body in a physical barrier with no cuts, scrapes, open sores, or breaks, and is covered with an acid mantle that creates an inhospitable environment for most bacteria.

How does the respiratory system defend against swallowed or inhaled foreign matter?

It traps inhaled foreign matter using nose hairs and its moist mucous membrane lining, uses tonsils to form a protective ring around the throat entrance, and uses coughing and sneezing to expel foreign matter that passes these barriers.

What is the primary function of the antigen-antibody reaction (immune reaction)?

It involves binding antigens to antibodies to label a potentially dangerous antigen so that it can be recognized and destroyed by other cells of the immune system.

What are the two definitions of tolerance described in the lecture?

Tolerance refers to an acquired unresponsiveness to a specific antigen, or a decline in the effective response to a drug usually due to repeated use.

What is Immunoglobulin G (IgG) and where is it located?

IgG is the most abundant class of antibodies, found in blood and lymph, and is active against bacteria, fungi, viruses, and foreign particles.

What is the primary function and distribution of Immunoglobulin A (IgA)?

IgA is produced predominantly against ingested antigens, found in body secretions such as saliva, sweat, or tears, and prevents the attachment of viruses and bacteria to epithelial surfaces lining most organs.

Which class of antibodies is the first to appear in response to an initial exposure to an antigen?

Immunoglobulin M (IgM), which is found in circulating body fluids.

Where is Immunoglobulin D (IgD) found, and what is its role?

IgD is found only on the surface of B cells and is important in B cell activation.

Where is Immunoglobulin E (IgE) produced and what is its primary role?

IgE is produced in the lungs and mucous membranes, and it is responsible for allergic reactions.

What is phagocytosis and which cells perform it?

Phagocytosis is the process of destroying pathogens by surrounding and swallowing them. It is performed by phagocytes, which include monocytes, macrophages, dendritic cells, and mast cells.

What happens to monocytes when they leave the bloodstream and enter tissue?

They become macrophages and dendritic cells.

What are the specific roles of a macrophage in the immune system?

A macrophage surrounds and kills invading cells, removes dead cells, and stimulates the action of other immune cells.

How do dendritic cells respond when they find an antigen that produces an infection?

The dendritic cell grabs the antigen, swallows it, and alerts BNT cells to act against that specific antigen.

What is the complement system and how does it assist antibodies?

It is a group of proteins that normally circulate in the blood in an inactive form. When needed, they combine with antibodies to dissolve and remove pathogenic bacteria and other foreign cells.

What is natural immunity (passive immunity) and how can it be augmented?

Natural immunity is disease resistance present at birth without the administration of an antigen or exposure to a disease. It can be augmented when breast milk passes from a nursing mother to her baby.

How is acquired immunity obtained?

Acquired immunity is obtained by having had a contagious disease or by being vaccinated against it.

How does an mRNA vaccine prompt the body to build antibodies?

An mRNA vaccine contains genetic instructions for a surface protein from the target virus, instructing cells to create the protein, which the body recognizes as foreign and builds antibodies against.