Pathophysiology Exam Review Flashcards

Flashcards covering key concepts from innate immunity, inflammation, wound healing, and adaptive immunity, preparing for the pathophysiology exam.

How do physical and mechanical barriers contribute to defense mechanisms?

They prevent entry of pathogens through tightly associated epithelial cells of skin and linings of tracts.

What are antimicrobial peptides?

Small peptides that kill or inhibit the growth of disease-causing bacteria, fungi, and viruses.

What role does the microbiome play in defense?

It protects against diseases through enzyme production, synthesis of metabolites, release of antibacterial substances, and fostering adaptive immunity.

What are opportunistic microorganisms?

Normal flora that can cause disease if the individual's defenses are compromised.

Why are innate immunity and inflammation described as "nonspecific"?

These responses occur in the same way regardless of the type of stimulus.

What are the five classic symptoms of acute inflammation?

Redness, swelling, heat, pain, and loss of function.

What are the first basic steps in acute inflammation?

Arterioles constrict briefly, then dilate, increasing blood flow.

What benefits does inflammation provide?

Prevents infection, controls the spread of damage, interacts with adaptive immune components, and prepares for healing.

What are the three key products of the complement system?

Opsonins, chemotactic factors, and anaphylatoxins.

How is the clotting cascade activated?

Through the intrinsic pathway by Hageman factor and the extrinsic pathway by tissue thromboplastin.

What are pattern recognition receptors (PRRs)?

Receptors that recognize patterns of infectious agents or damage.

What are cytokines?

Intracellular messengers produced during inflammation that promote immune responses.

What products do mast cells release during inflammation?

Histamine, neutrophil and eosinophil chemotactic factors, and prostaglandins.

What role do neutrophils play in inflammation?

First phagocytic responders that ingest pathogens and debris.

What is the function of opsonins?

To coat target bacteria or cells, enhancing phagocytosis.

What are the four steps in phagocytosis?

Recognition and adherence, engulfment, fusion with lysosomes, and destruction.

How does acute inflammation differ from chronic inflammation?

Acute inflammation lasts a short time with immediate responses, while chronic inflammation persists and may involve lymphocytes and macrophages.

What types of exudate are produced in inflammation?

Serous, fibrinous, purulent, and hemorrhagic exudate.

What is a granuloma?

A structure formed to isolate areas of infection when macrophages cannot control it.

How does tissue regeneration differ from tissue repair?

Regeneration restores original structure and function, while repair replaces tissue with scar tissue.

What are the characteristics of wounds healing by primary intention?

Healing occurs with minimal tissue loss and primarily through collagen synthesis.

What is the function of fibroblasts in wound healing?

To synthesize collagen and fibrin for tissue repair.

What can lead to dysfunctional wound healing?

Insufficient, excessive, or delayed healing due to various factors including infection or nutrition.

What distinguishes innate from acquired immunity?

Innate immunity is present at birth; acquired immunity develops from exposure to antigens.

What is humoral immunity?

Immunity involving B lymphocytes and the production of antibodies.

What is cell-mediated immunity?

Immunity involving T lymphocytes that directly attack infected cells.

What is clonal selection?

The process that occurs upon antigen exposure, leading to differentiation of B and T cells.

Define antigen. What is an immunogen?

Antigen binds to antibodies; an immunogen induces an immune response.

What is clonal diversity?

The generation of a wide variety of B and T cells capable of recognizing foreign antigens.

What is the role of BCRs and TCRs?

To recognize antigens and prevent the body from attacking self.

What is central tolerance?

Elimination of autoreactive B cells to prevent immune response against self-antigens.

What are antigen-presenting cells (APCs)?

Cells like macrophages and B cells that present antigens to T cells.

What is the role of T-helper cells?

To assist in the immune response and activate other immune cells.

Why are memory cells important?

They enable a faster and stronger immune response upon re-exposure to the same antigen.

What are the major classes of antibodies?

IgG, IgM, IgA, IgD, and IgE.

What are the major functions of antibodies?

To protect against infection through direct or indirect mechanisms.

What does the secretory immune system protect?

The external surfaces of the body, such as mucosal surfaces.

What is primary immune response?

The initial antibody response occurring after the first exposure to an antigen.

What is secondary immune response?

A faster and more effective antibody production following re-exposure to an antigen.

What are the functions of T cytotoxic cells?

To destroy abnormal cells like tumor or virus-infected cells.

How do NK cells differ from T cytotoxic cells?

NK cells do not have antigen-specific receptors and can kill without prior sensitization.

What is the role of Treg cells?

To regulate immune responses and maintain tolerance.

What is hypersensitivity?

An exaggerated immune response that can cause tissue damage.

Define Type I hypersensitivity. What triggers it?

Immediate allergic reaction triggered by IgE antibodies.

What is anaphylaxis?

A severe, rapid allergic reaction that can lead to shock.

What examples are there of Type IV hypersensitivity?

Graft rejection, tuberculin reactions, and delayed allergic reactions.

Why can some drugs become immunogenic?

When they bind to host proteins, forming neoantigens recognized as foreign.

Why is type O blood a universal donor?

It lacks A and B antigens, reducing the risk of transfusion reactions.

What characterizes autoimmune diseases like SLE?

The presence of autoantibodies that attack the body's own components.

What are the main types of graft rejections?

Hyperacute, acute, and chronic rejection.

Why is recurrent infections a hallmark of immunodeficiency?

Ineffective immune responses lead to an inability to fight infections.

How do cell-mediated deficiencies differ from humoral deficiencies?

Cell-mediated issues affect T-cell responses; humoral deficiencies affect B-cell responses.

How does HIV affect the immune system?

By destroying CD4+ T-helper cells, impairing the body's immune response.

What are the steps involved in the process of infection?

Transmission, colonization, and invasion.

What are the mechanisms of tissue damage caused by pathogens?

Direct cell lysis, toxin production, immune-mediated damage, and inflammation.

What are the four stages of infection?

Incubation, prodromal, invasion, and convalescence.

How do antigenic changes in viruses promote disease?

They allow viruses to evade immune detection.

What are the mechanisms pathogens use to block the immune system?

Antigenic drift, shift, and gene switching.

What is the difference between endotoxin and exotoxin?

Endotoxins are part of the bacterial cell wall; exotoxins are proteins secreted by bacteria.

How do bacteria develop antibiotic resistance?

Through genetic mutations, plasmid transfer, and selective pressures.

What is the clinical significance of antibiotic resistance?

It limits treatment options and increases infection severity.