Micro Exam 3 review

Signs vs. Symptoms

Signs are objective evidence of disease while symptoms are subjective experiences reported by victims.

Infectious Diseases

Diseases caused by pathogens.

Non-infectious Diseases

Diseases caused by genetic or environmental factors.

Acute Diseases

Diseases with rapid onset and short duration.

Chronic Diseases

Diseases that are long-lasting, may be controlled, but not cured.

Latent Diseases

Diseases that have dormant stages and can re-emerge.

Incubation Period

The time from exposure to the disease to the appearance of symptoms.

Prodromal Period

Onset of vague symptoms.

Illness Period

The peak stage of disease.

Decline Period

The stage when symptoms begin to subside.

Convalescence Period

The stage of recovery and restoration of health.

Normal Human Flora

Microbes that inhabit the body normally, some of which are beneficial.

Transient Flora

Temporary microbes that reside in the host.

Resident Flora

Permanent microbes that benefit the host.

Sterile Anatomical Sites

Body parts that are normally free of microbes.

Consequences of Disruption in Flora

Can lead to infections such as Clostridium difficile after antibiotic use.

Pathogens

Microorganisms that cause disease.

Virulence

The degree of pathogenicity of a microorganism.

Endogenous Infections

Infections arising from normal flora due to changes in host immunity.

Opportunistic Infections

Infections occurring when the body's defenses are weakened.

Infectious Dose (ID)

The minimum quantity of pathogen needed to cause disease.

Contact (Portals of Entry)

Routes through which pathogens enter the host.

Adhesion

Mechanisms by which pathogens adhere to host tissues.

Establishment

The colonization of pathogens at the site of entry.

Tissue Damage

Damage to tissues often caused by pathogen metabolic products.

Endotoxins

Components of the cell wall in Gram-negative bacteria that can trigger immune responses.

Exotoxins

Secreted proteins from bacteria that damage host tissues.

Local Infections

Infections confined to a specific area.

Systemic Infections

Infections that spread throughout the body.

Focal Infections

Infections that spread from a local point to other areas.

Asymptomatic Carriers

Individuals who harbor infectious agents without showing symptoms.

Primary Infection

The initial infection.

Secondary Infection

Complications occurring after a primary infection.

Portals of Exit

Routes through which pathogens exit the host.

Endemic

Constant presence of a disease within a given geographic area.

Pandemic

An outbreak occurring over a wide geographical area.

Reservoir

Natural habitat of a pathogen.

Definitive Host

Organism where the pathogen reaches maturity.

Intermediate Host

Organism that harbors immature stages of a pathogen.

Source

Direct origin of the pathogen prior to transmission.

Carrier

Individual who can transmit an infectious agent without showing symptoms.

Direct Contact Transmission

Physical transfer of pathogens between individuals.

Indirect Contact Transmission

Transmission via inanimate objects.

Vehicle Transmission

Transmission via contaminated inanimate materials.

Vector Transmission

Transmission via living organisms.

Healthcare-Associated Infections (HAIs)

Infections acquired in healthcare settings.

Nosocomial Infections

Infections acquired in healthcare settings that are often resistant to treatment.

Innate Immunity

Immediate immune response that is not pathogen-specific.

Adaptive Immunity

Immune response that develops after exposure and is pathogen-specific.

First Line of Defense

Physical and chemical barriers preventing pathogen entry.

Second Line of Defense

Non-specific immune responses like inflammation.

Third Line of Defense

Involves immune cells like T and B cells.

Physical Defenses

Barriers such as skin and membranes that prevent infections.

Chemical Defenses

Secretions that inhibit pathogens, such as stomach acid.

Cellular Defenses

Responses involving white blood cells.

Granulocytes

Type of white blood cells that facilitate inflammation.

Agranulocytes

Type of white blood cells including lymphocytes crucial for adaptive immunity.

Pathogen Recognition

The ability of cells to recognize pathogens via PRRs.

Inflammatory Response

Increased blood flow and immune cell recruitment.

Fever

Defense mechanism increasing body temperature to inhibit pathogens.

Phagocytosis

Process by which cells engulf and digest pathogens.

Interferons

Proteins that enhance defenses in neighboring cells during viral infections.

Complement System

Group of proteins that enhance immune responses.

Humoral Immunity

B cell-mediated production of antibodies.

Cell-Mediated Immunity

T cell involvement and activation in response to specific pathogens.

Epitopes

Specific portions of antigens recognized by the immune system.

Haptens

Small molecules made immunogenic when attached to larger carriers.

Antibodies/Immunoglobulins

Proteins that recognize and bind specific antigens.

IgG

Most common antibody providing long-term immunity.

IgA

Antibody found in mucosal areas protecting body surfaces.

IgM

First antibody produced in response to infection.

IgE

Involved in allergic responses and defense against parasites.

IgD

An antibody with mostly unknown functions but assists in B cell activation.

Antigen-Antibody Interactions

Neutralization, opsonization, agglutination and complement system activation.

MHC Molecules

Major Histocompatibility Complex molecules involved in immune response.

MHC Class I

Molecules present on nucleated cells recognized by CD8+ T cells.

MHC Class II

Molecules present on antigen-presenting cells recognized by CD4+ T cells.

Development of Lymphocytes

B and T cells develop in bone marrow and thymus respectively.

Helper T Cells

Assist in activating B cells and cytotoxic T cells through cytokines.

Cytotoxic T Cells

Cells that kill infected or cancerous cells.

Clonal Selection

Proliferation and differentiation of specific lymphocytes in response to an antigen.

Natural Immunity

Developing immunity through prior infection.

Artificial Immunity

Immunization or passive transfer of antibodies.

Active Immunity

Immunity involving the stimulation of the immune system.

Passive Immunity

Immunity by receiving pre-formed antibodies.

Classes of Vaccines

Live-attenuated, inactivated, subunit, and mRNA vaccines.

Herd Immunity

Immunity in a significant portion of the population that controls disease spread.

Lesion

Any abnormal tissue change inclusive of rashes or sores.

Bacterial Skin Infections

Infections caused by bacteria affecting the skin.

Staphylococcus

Genus of bacteria known for causing skin conditions.

Staphylococcus aureus

Bacteria known for MRSA infections.

Streptococcus

Bacteria responsible for conditions such as scarlet fever.

Pseudomonas aeruginosa

Opportunistic pathogen found in burn victims.

Bacillus anthracis

Bacterium causing anthrax, treated effectively with antibiotics.

Bacterial Conjunctivitis

Highly contagious eye infection with redness and discharge.

Neonatal Conjunctivitis

Eye infection in newborns often due to maternal infections.

Trachoma

Chronic eye infection that can lead to blindness.

Bacterial Keratitis

Infection of the cornea characterized by pain and vision problems.

Human Papillomavirus (HPV)

Virus that leads to warts, with some strains causing cancers.

Human Herpesviruses

Viruses causing oral and genital herpes.