ch 14_lecture

Innate Immunity

The first line of defense against pathogens, providing routine protection and responding rapidly to invaders.

Phagocytes

Cells that ingest and destroy foreign material, including invading microbes.

Granulocytes

A type of white blood cell containing cytoplasmic granules, including neutrophils, eosinophils, and basophils.

Cytokines

Proteins produced by immune cells that communicate and regulate immune responses between cells.

Chemotaxis

The movement of cells toward the site of infection or injury in response to chemical signals.

Opsonization

The process by which pathogens are marked for destruction by coatingthem with antibodies or complement proteins, enabiling easier phagocytosis

Complement System

A group of proteins in the blood that enhance the ability of antibodies to clear pathogens, promote inflammation, and destroy invading cells.

Dendritic Cells

Antigen-presenting cells that process material and present it to T cells, acting as 'scouts' in the immune system.

Inflammatory Response

A complex biological response to harmful stimuli, involving immune cells, blood vessels, and molecular mediators to eliminate the initial cause of cell injury.

Natural Killer Cells

A type of lymphocyte that provides a rapid response to virally infected cells and react to tumor formation.

Lysozyme

An enzyme that breaks down bacterial cell walls, found in bodily secretions and plays an antimicrobial role.

Mucous Membranes

Physical barriers that line the cavities of the body and produce mucus to trap pathogens and particles.

Eosinophils

White blood cells that primarily combat parasitic infections and are involved in allergic reactions.

Macrophages

Large phagocytic cells that ingest and digest cellular debris, foreign substances, and pathogens.

Adaptive Immunity

A specialized immune response that develops over time, characterized by a highly specific response to antigens.

C3 Convertase

An enzyme complex in the complement system that splits C3 to initiate the complement cascade.

Apoptosis

Programmed cell death, a process that eliminates damaged or unnecessary cells without triggering inflammation.

Fever

A temporary increase in body temperature often due to an immune response to infection, enhancing defense mechanisms.

Pathogen-Associated Molecular Patterns (PAMPs)

Molecular structures recognized by the immune system that indicate the presence of a pathogen.

Pattern Recognition Receptors (PRRs)

Receptors in the innate immune system that detect PAMPs and induce immune responses.

Interferons

Cytokines that are part of the immune response to viral infections, promoting antiviral defenses in cells.

Colony-Stimulating Factors (CSFs)

Proteins that stimulate the production of immune cells

Microbial Flora

microbiota that prevent pathogen colonization through competitive exclusion and production of toxic compounds.

Membrane Attack Complex (MAC)

A structure formed on the surface of a pathogen by the complement system that leads to cell lysis.

Chemokines

Cytokines that induce chemotaxis, guiding immune cells to sites of infection.

Erythrocytes

Red blood cells responsible for transporting oxygen throughout the body.

Lymphocytes

White blood cells that are central to adaptive immunity, including B cells and T cells.

Resident Macrophages

Macrophages that remain in tissues and are involved in surveillance and immune response.

Neutrophils

The most abundant type of white blood cell, part of the innate immune response, and primarily involved in phagocytosis.

Clotting Factors

Proteins in blood that promote coagulation and contribute to hemostasis.

Histamine

A chemical that is released during inflammatory responses, increasing vascular permeability and attracting immune cells.

Apoptosis vs Pyroptosis

Apoptosis is controlled cell death without inflammation, while pyroptosis is cell death that triggers inflammation.

Fluid Leakage in Inflammation

Occurs during inflammation, leading to swelling and pain in the affected area as blood vessels become more permeable.

Comparison of Innate and Adaptive Immunity

Innate immunity is a rapid, non-specific response to pathogens, while adaptive immunity is slower but provides a highly specific response to antigens and has memory.

Self

Refers to the body's own cells and molecules that the immune system recognizes as non-threatening.

Inflammation

A protective response of the immune system characterized by redness, heat, swelling, and pain, aimed at eliminating pathogens and initiating healing.

First-Line Defense

The body's initial barriers to infection, including skin, mucous membranes, and various secretions.

Lysozyme

An enzyme that breaks down bacterial cell walls, found in secretions like saliva and tears.

Peroxidase

An enzyme that produces reactive oxygen species to kill bacteria in immune responses.

Lactoferrin

A protein that binds iron, limiting its availability to pathogens and possessing antimicrobial properties.

Surface Receptors

Proteins on the surface of cells that recognize and bind to pathogens or their components, activating immune responses.

Interleukins (ILs)

A group of cytokines produced by leukocytes that help to regulate immune responses and cell communication.

Tumor Necrosis Factors (TNFs)

Cytokines involved in systemic inflammation and the acute phase reaction, primarily produced by macrophages. Inducese apoptosis

Mechanical Factors Preventing Microorganism Invasion

Includes skin integrity, mucous membrane barriers, and the expulsion of pathogens through ciliary actions and secretions.

Role of Normal Microbiota

Normal microbiota competes with pathogens for space and nutrients, produces substances that inhibit pathogen growth, and helps stimulate immune responses.

Neutrophils

White blood cells that are the first responders to infection, conducting phagocytosis and releasing enzymes.

Basophils

A type of white blood cell that releases histamine and plays a role in inflammatory and allergic responses.

Eosinophils

White blood cells that are primarily involved in combating parasitic infections and allergic reactions.

Monocytes

Large white blood cells that differentiate into macrophages and dendritic cells in tissues.

Lymphocytes

White blood cells that play a central role in adaptive immunity, including B cells and T cells.

Function of Toll-Like Receptors

Receptors that recognize pathogen-associated molecular patterns (PAMPs) and initiate innate immune responses.

Complement

A system of proteins in the blood that enhances the immune response by promoting pathogen destruction.

Classical, Lectin, and Alternative Complement Pathways

Different pathways of complement activation: classical relies on antibodies, lectin binds to pathogen sugars, and alternative is triggered by pathogens directly.

Outcomes of Complement Fixation

Includes pathogen lysis, opsonization for enhanced phagocytosis, and inflammation promotion.

Phagocytosis

The process by which immune cells engulf and digest pathogens and debris through a series of steps.

Chemotaxis

The movement of immune cells toward higher concentrations of signaling molecules at sites of infection.

Phagolysosome

A vesicle formed by the fusion of a phagosome containing the ingested material and lysosomes with digestive enzymes.

Functions of Inflammation

Serves to recruit immune cells, increase blood flow to the area, and initiate repair processes. Cardinal signs are redness, heat, swelling, pain, and loss of function.

Fever and Induction Process

Fever is an increase in body temperature that enhances immune function, typically induced by pyrogens released during infections.