Disease + Immunity + Antibodies - Flashcards

A comprehensive set of Q&A flashcards covering disease types, malaria life cycle, immunity (innate and acquired), lymphoid organs, antibodies, immune responses, and related clinical concepts.

What defines a congenital disease?

A genetically inherited disease present at birth that can affect one or more organs or organ systems, altering body function and showing signs and symptoms.

What defines an acquired disease?

A disease that develops after birth and is characterized by signs and symptoms.

What is the difference between infectious and non-infectious diseases?

Infectious diseases can spread from one person to another; non-infectious diseases do not spread person-to-person.

What does contagious mean in the context of diseases?

A contagious disease is infectious and can spread directly from person to person.

What organism causes malaria and what category does it belong to?

Malaria is caused by Plasmodium, a protozoan parasite.

Who are the hosts involved in the malaria life cycle and which one is the vector?

Humans and mosquitoes are hosts; the Anopheles mosquito is the vector.

What is the malaria vector and how is it transmitted to humans?

The Anopheles mosquito; sporozoites are transmitted to humans through the mosquito's bite in its saliva.

Where does fertilization and development occur in the malaria life cycle?

In the mosquito’s gut.

Where do gametocytes develop and what is their role?

Gametocytes develop in red blood cells; they are taken up by a mosquito during a blood meal and fertilization occurs in the mosquito.

Where do sporozoites go after entering the human host and what do they do there?

They reach the liver and multiply asexually, producing merozoites that enter the bloodstream.

What causes the fever cycles in malaria?

Asexual replication of Plasmodium in red blood cells causing rupture of cells and release of merozoites.

What is immunity?

Resistance to a pathogen or disease; the body's overall ability to fight disease, mediated by the immune system.

What is an antigen?

A substance that stimulates the production of antibodies; it triggers an immune response.

What is an antibody?

A complex glycoprotein secreted by B-lymphocytes in response to an antigen.

What is an antigen–antibody reaction?

The interaction between an antigen and its specific antibody produced by B-lymphocytes.

What are the primary lymphoid organs?

Bone marrow and thymus, where lymphocytes are produced and mature.

What are the secondary lymphoid organs?

Lymph nodes, spleen, tonsils, Peyer’s patches, appendix; sites where lymphocytes encounter antigens.

What does MALT stand for and what is its role?

MALT = mucosa-associated lymphoid tissue; contributes to immune responses at mucosal surfaces.

Where are B and T lymphocytes produced or matured?

B lymphocytes are produced in bone marrow; T lymphocytes mature in the thymus.

Where are the majority of lymphocytes located?

The majority circulate in the blood and reside in lymphoid tissues as part of the immune surveillance.

What are the main features of innate (non-specific) immunity?

Present at birth, non-specific, memoryless; includes cells like monocytes, neutrophils, NK cells, macrophages, plus barriers and chemical defenses.

Name some physical barriers of innate immunity.

Skin and mucosal surfaces.

What are interferons?

Antiviral proteins secreted by virus-infected cells to help inhibit viral replication.

What are the cellular components of innate immunity?

Monocytes, neutrophils, macrophages, and natural killer (NK) cells.

What is acquired (adaptive) immunity?

Specific immune response with memory, involving B and T lymphocytes; can be active or passive and natural or artificial.

What are the 3Rs of acquired immunity?

Recognition, Response, Remember (memory).

What is the difference between a primary and a secondary immune response?

Primary response occurs on first exposure and is slow with lower antibody levels; secondary response occurs on subsequent exposures and is faster with higher antibody levels due to memory.

Who produces antibodies in the body?

B-lymphocytes (B cells) produce antibodies (immunoglobulins).

What is the role of T-lymphocytes in antibody production?

T-lymphocytes help B cells to produce antibodies (they assist the antibody response).

What is the basic structure of an antibody?

Two heavy chains and two light chains linked by disulfide bonds; contains variable and constant regions; antigen-binding site (paratope) formed by variable regions; Fab and Fc regions.

What is the antigen-binding site called and what is the antigenic determinant on an antigen?

Antigen-binding site = paratope; the antigenic determinant on the antigen is the epitope.

What is graft rejection?

An immune response against non-self tissues or organs transplanted into the body.

What are allergies and the role of IgE?

Allergies are hypersensitive immune responses to environmental allergens mediated by IgE antibodies; antihistamines are commonly used treatments.

What is autoimmunity?

An immune response in which the body's immune system attacks its own cells.

What is AIDS and what virus causes it?

AIDS stands for Acquired Immunodeficiency Syndrome, caused by HIV, a retrovirus with an RNA genome that weakens the immune system.

What is cancer and what factors contribute to it?

Cancer is uncontrolled, abnormal cell division; carcinogens and oncogenic changes can initiate and promote cancer development.