Unit 3 Study Guide

These flashcards cover key concepts from the study guide for Unit 3, including interactions between humans and microbes, aspects of infectious diseases, immune system characteristics, and autoimmune diseases.

What are some major interactions between humans and microbes in our habitats?

Humans interact with microbes in ways including mutualism, commensalism, and parasitism.

What is the definition of infectious diseases?

Infectious diseases are illnesses caused by pathogenic microorganisms, like bacteria, viruses, parasites, or fungi.

What are the characteristics and functions of normal microbiota?

Normal microbiota include beneficial bacteria that perform functions such as digestion, protection against pathogens, and immune system modulation.

Which bodily sites remain free of living organisms?

Sites such as the bloodstream and internal tissues remain free of living organisms to prevent infections and maintain health.

What is meant by the germ-free condition?

Germ-free condition refers to environments devoid of microorganisms, important for studying the role of microbes in health and disease.

What are the main stages in the development of an infection?

The main stages include exposure, adherence, invasion, multiplication, and transmission.

What is the difference among the portals of entry?

Portals of entry are pathways through which pathogens enter the body; examples include the skin, respiratory tract, and gastrointestinal tract.

What is an infectious dose?

Infectious dose is the number of microorganisms required to establish an infection, which varies by pathogen.

What is adhesion in microbial invasion?

Adhesion is the process by which microbes attach to host cells using various mechanisms, facilitating entry.

What are invasive factors and virulence factors?

Invasive factors are attributes that enable pathogens to invade host tissues, while virulence factors contribute to their ability to cause disease.

What are the major characteristics of exotoxins and endotoxins?

Exotoxins are potent, secreted toxins produced by bacteria, whereas endotoxins are components of bacterial cell walls released upon cell lysis.

What are the clinical stages of infection?

The clinical stages of infection include incubation, prodromal, acute, convalescent, and resolution stages.

What are the patterns of infection?

Patterns of infection can include localized, systemic, and focal infections.

What are the manifestations of infections and inflammation?

Manifestations include symptoms like fever, pain, swelling, and redness.

What are the major portals of exit for pathogens?

Portals of exit include respiratory secretions, blood, urine, and feces.

What is epidemiology?

Epidemiology is the study of how diseases spread and can be controlled in populations.

What are carriers in infectious diseases?

Carriers are individuals who can transmit pathogens without exhibiting symptoms.

What are the different types of vectors?

Vectors can be biological (like mosquitoes) or mechanical (like flies), and zoonoses are diseases transmitted from animals to humans.

What is the difference between communicable and noncommunicable diseases?

Communicable diseases are spread from person to person, while noncommunicable diseases are not transmitted between individuals.

What are the patterns of transmission for communicable diseases?

Patterns include direct contact, droplet transmission, vector-borne transmission, and airborne transmission.

What are the methods of tracking infections?

Methods include surveillance, reporting systems, and contact tracing.

What are the patterns of disease outbreaks?

Outbreak patterns can be measured by frequency (sporadic, endemic, epidemic), number of cases, and geographic location.

What are healthcare-associated infections?

Infections acquired in healthcare settings, often affecting patients with weakened immune systems.

What are universal precautions?

Practices designed to prevent transmission of diseases through blood and other bodily fluids.

What are the basic characteristics of host defenses?

Host defenses include physical barriers, innate immune responses, and adaptive immunity.

What are the three lines of defense?

First line: physical barriers, second line: innate immune responses, third line: adaptive immunity.

What are innate defenses?

Innate defenses are non-specific responses, including barriers, phagocytosis, and inflammation.

What are the primary organs of the immune system?

Key organs include the thymus, bone marrow, spleen, and lymph nodes.

What is the recognition system of host defenses?

A system comprising specialized cells that identify and respond to pathogens.

What are pattern recognition receptors?

Molecules used by the immune system to detect pathogens and initiate responses.

What is the mononuclear phagocyte system?

A network of phagocytic cells that plays a crucial role in the immune response.

What is the origin and composition of blood?

Blood is composed of plasma, red blood cells, white blood cells, and platelets, originating from hematopoietic stem cells.

How do white blood cells behave in circulation and tissues?

White blood cells exit bloodstream to reach tissues, where they perform immune functions.

What are the characteristics of the lymphatic system?

A system that maintains fluid balance, absorbs fats, and is integral to the immune response.

What occurs during the inflammatory reaction?

The inflammatory reaction involves vascular changes, immune cell recruitment, and tissue repair processes.

What are cytokines and chemokines?

Cytokines are signaling proteins that mediate immune responses, while chemokines recruit immune cells to sites of infection.

What is the mechanism behind fever?

Fever results from the hypothalamus raising body temperature in response to infection, which can enhance immune function but may also be harmful.

What is phagocytosis?

Phagocytosis is the process by which certain immune cells engulf and digest pathogens.

What are the stages of phagocytosis?

Stages include recognition, engulfment, formation of a phagosome, fusion with lysosome, and destruction of the pathogen.

How do phagocytes kill pathogens?

Phagocytes use reactive oxygen species, enzymes, and antimicrobial peptides to destroy pathogens.

What is the role of interferon?

Interferon is produced by infected cells to modulate the immune response and inhibit viral replication.

What is the complement system?

A group of proteins that enhance the immune response through opsonization, lysis of pathogens, and inflammation.

What are the features of adaptive immunity?

Adaptive immunity is characterized by specificity, memory, and the ability to adapt to different pathogens.

What is immunocompetence?

Immunocompetence refers to the ability of the immune system to recognize and mount a response to antigens.

What are the phases of a specific immune response?

Phases include recognition, activation, and effector phases leading to clearance of pathogens.

What are immune receptors?

Molecules on immune cells that recognize and bind antigens, leading to an immune response.

What is the development of antigen receptors on lymphocytes?

Lymphocytes develop antigen receptors through gene rearrangement processes in the thymus and bone marrow.

What are the differences between B-cell and T-cell maturation?

B cells mature in bone marrow, while T cells mature in the thymus, with different functional roles in the immune response.

What are antigens and epitopes?

Antigens are substances that provoke an immune response; epitopes are specific parts of antigens recognized by immune receptors.

What are the categories of antigens?

Categories include exogenous antigens (from outside the body) and endogenous antigens (produced by the body).

What are cooperative interactions between antigen-presenting cells and T/B cells?

Antigen-presenting cells activate T cells, which in turn help activate B cells for antibody production.

What is the role of interleukins?

Interleukins are cytokines that mediate communication between immune cells during recognition and activation stages.

What are cell-mediated immunities?

Immune responses that involve T cells attacking infected or cancerous cells directly.

What are the functions of helper T cells?

Helper T cells activate other immune cells, including B cells and cytotoxic T cells, enhancing the immune response.

What are the functions of cytotoxic T cells?

Cytotoxic T cells kill infected or cancerous cells directly by inducing apoptosis.

What are natural killer cells?

Natural killer cells are a type of lymphocyte that can destroy infected or tumor cells without prior sensitization.

What are superantigens?

Superantigens are a class of antigens that provoke an excessive immune response by activating many T cells.

What are the stages in B lymphocyte activation?

Stages include recognition of antigen, clonal expansion, and differentiation into plasma cells for antibody production.

What are the five major types of immunoglobulins?

IgG, IgA, IgM, IgD, and IgE, each with specific functions in the immune response.

What are the actions of antibodies?

Antibodies neutralize pathogens, opsonize them for phagocytosis, and activate the complement system.

What are the primary and secondary responses to antigens?

Primary response is the initial immune response, while secondary response is faster and stronger due to memory cell activation.

What is the importance of the anamnestic response?

The anamnestic response is the rapid increase in antibody production upon reexposure to an antigen.

What are the categories of adaptive immunity?

Categories include natural (acquired through infection) and artificial (acquired through vaccination) immunity.

What is the difference between active and passive immunity?

Active immunity results from the immune system's response to an antigen, while passive immunity is acquired through transfer of antibodies.

What are the purposes of immunotherapy and immunization?

Immunotherapy aims to enhance or restore immune function, while immunization aims to induce protective immunity.

What is artificial passive immunization?

Artificial passive immunization involves the direct transfer of antibodies to an individual for immediate protection.

What is artificial active immunization?

Artificial active immunization involves administering a vaccine to stimulate an immune response.

What factors are involved in vaccine development?

Factors include safety, efficacy, stability, and the economic feasibility of manufacturing and distribution.

What are the major categories of vaccine antigens?

Categories include live attenuated, inactivated, subunit, and toxoid vaccines.

What are the medical guidelines for vaccination?

Guidelines include recommended immunization schedules, monitoring for side effects, and considerations for herd immunity.

What are hypersensitivities?

Hypersensitivities are exaggerated immune responses that can cause damage to host tissues.

What factors are involved in allergies?

Allergies arise from genetic predisposition and environmental exposure to allergens.

What are the general characteristics of allergic reactions?

Allergic reactions typically involve an immediate response, inflammation, and may cause symptoms like itching and swelling.

What are the major allergen categories?

Categories include pollen, dust mites, mold, pet dander, and certain foods.

What is the mechanism of immediate allergies?

Immediate allergies involve IgE binding to allergens, triggering mast cell degranulation and release of histamines.

What are the physiological effects of allergies?

Physiological effects can include bronchoconstriction, vasodilation, and increased vascular permeability.

What are the types of atopic allergies?

Atopic allergies include allergic rhinitis, asthma, and atopic dermatitis, characterized by chronic inflammation.

What is anaphylaxis?

Anaphylaxis is a severe, life-threatening allergic reaction that can cause shock and respiratory distress.

What are the primary methods of diagnosing allergies?

Diagnosis methods include skin tests, blood tests, and patient history assessments.

What is type II hypersensitivity?

Type II hypersensitivity involves antibody-mediated destruction of cells, often seen in blood transfusion reactions.

What are blood groups?

Blood groups are classifications of blood based on the presence or absence of antigens on red blood cells.

What are the special concerns about the Rh factor?

The Rh factor can cause hemolytic disease of the newborn if an Rh-negative mother has an Rh-positive baby.

What is type III hypersensitivity?

Type III hypersensitivity involves immune complex formation that can trigger inflammation and tissue damage.

What is type IV hypersensitivity?

Type IV hypersensitivity is a delayed-type response mediated by T cells, seen in contact dermatitis.

What are contact dermatitis mechanisms?

Contact dermatitis arises when the skin reacts to allergens or irritants, leading to inflammation.

What is the involvement of T cells in organ transplantation?

T cells can recognize transplanted tissues as foreign and mediate rejection if not properly matched.

What are graft categories?

Categories include autografts (from the same individual), allografts (from a donor of the same species), and xenografts (from different species).

What is autoimmune disease pathology?

Autoimmune diseases involve the immune system mistakenly attacking the body’s own cells and tissues.

What are the origins of autoimmunity?

Autoimmunity can be triggered by genetic, environmental, or infections, often targeting specific tissues.

What are the major types of autoimmune diseases?

Major types include rheumatoid arthritis, lupus, multiple sclerosis, and type 1 diabetes.

How does immune function relate to cancer development?

Dysregulation of immune responses can promote tumor development and progression.