Human Physiology: Body Defenses

Flashcards covering key concepts related to the immune system and body defenses.

First line of defense

Includes the skin, lungs, and digestive system that protect the body from pathogens.

Antibody

A Y-shaped molecule produced by plasma cells that binds to specific antigens to neutralize them.

Pathogen

An organism that can cause disease, such as bacteria and viruses.

Phagocytosis

The process by which certain cells engulf and destroy pathogens.

B cells

Lymphocytes that produce antibodies for antibody-mediated immunity.

T cells

Lymphocytes that are involved in cell-mediated immunity and directly destroy infected or cancerous cells.

Innate immune system

The non-specific part of the immune system that responds immediately to pathogens.

Adaptive immune system

The part of the immune system that targets specific pathogens and builds a memory response.

Cytokines

Proteins that mediate and regulate immune responses.

Autoimmune disease

A condition where the immune system mistakenly attacks the body’s own tissues.

MHC (Major Histocompatibility Complex)

Molecules that present antigens on the surface of cells to T cells.

Clonal selection

The process by which a specific B or T cell is activated and proliferates in response to a particular antigen.

Self-tolerance

The immune system's ability to recognize and not attack the body’s own tissues.

Natural killer cells

Lymphocytes that can destroy virus-infected cells and tumor cells without prior sensitization.

Complement system

A group of plasma proteins that enhance the immune response by promoting inflammation and cell lysis.

Antigen

A substance that triggers an immune response, typically a large, complex molecule.

Neutrophils

A type of white blood cell that plays a crucial role in the immune response, primarily by fighting off infections, especially bacterial attacks.

Lymphocytes

A type of white blood cell that is integral to the immune system; there are B cells (which produce antibodies) and T cells (which destroy infected or cancerous cells).

Monocytes

A type of white blood cell that differentiates into macrophages and dendritic cells to help in the immune response by ingesting pathogens.

Eosinophils

A type of white blood cell involved in combating parasites and allergic reactions.

Basophils

The least common type of white blood cell, which plays a role in allergic reactions by releasing histamine and other chemicals.

Exogenous Factors

Exogenous factors are influences that come from outside an organism or system, such as environmental conditions, lifestyle choices, or external stimuli. They can impact health, behavior, and processes significantly.

Endogenous Factors

Endogenous factors are influences that originate from within an organism or system, including genetic makeup, biological processes, and internal physiological mechanisms. They are inherent to the individual or system and can determine traits and responses.

Examples of Exogenous Factors

Examples include diet, exercise, environmental toxins, and exposure to pathogens. These factors can affect the body's health and disease risk.

Examples of Endogenous Factors

Examples include genetic predisposition, hormone levels, and metabolic functions. These factors are intrinsic and can influence growth, development, and health status.

Nonsteroidal anti-inflammatory drugs and

glucocorticoids

suppresses inflammation

Innate Lymphoid Cells (ILCs)

ILCs are innate immune cells that function similarly to helper T cells by spurring other immune cells into action, thus playing a crucial role in the immune response.

Innate Response Activator (IRA) B Cells

recognizes bacteria through Toll-like receptors (TLRs) and produce cytokines to initiate an immune response.

B cells

originate and mature in bone marrow

T cells

originate in the bone marrow and mature in the thymus

Three types of T cells

Cytotoxic, helper, and regulatory

T cells only respond

to antigens that are presented by antigen-presenting cells.

Cytotoxic T Cells

secrete chemicals that destroy target cells

Clone

family of identical cells

Antigens stimulate

B cells to convert into plasma cells that produce antibodies

IgM

can neutralize pahtogens

IgG

specific response against bacterial infections

IgE

produce against parasitic worms involved in allergic reactions

IgA

first line of defenses

IgD

present on B cells, function unknown

Role of thymosin

hormone secreted by the thymus, and maintains T cells lineage

exogenous

pathogen associated pattern

endogenous

damage associated pattern. Releases ATP

Antibodies

amplify innate immune responses