Immunity Types and Innate vs. Adaptive Immune Responses

Mucous Membranes

Tissues that line various cavities and structures of the body, providing a barrier and secreting mucus to trap pathogens.

Phagocytosis

The process by which certain cells engulf and digest foreign particles or pathogens.

Inflammation

A biological response to harmful stimuli, characterized by redness, heat, swelling, and pain, aimed at eliminating the cause of injury.

What is innate immunity?

Non-specific, immediate defense against pathogens that does not require prior exposure

What is adaptive immunity?

Specific immune response that targets particular antigens and develops memory

What structures provide mechanical protection in innate immunity?

Skin, mucous membranes, mucus, tears, saliva, nose, ciliary escalator, urethra

What is the role of the epidermis in immunity?

Acts as a physical barrier to prevent pathogen entry

What does mucus do in immune defense?

Traps microbes and particles

What is the function of the ciliary escalator?

Moves mucus and trapped microbes out of the respiratory tract

What provides chemical protection in innate immunity?

Sebum, perspiration, lysozyme, gastric juice

What is lysozyme?

An enzyme that breaks down bacterial cell walls

How does gastric juice protect the body?

Low pH destroys many pathogens

What are the steps of phagocytosis?

Chemotaxis, adherence, ingestion, digestion

What is chemotaxis?

Movement of phagocytes toward infection site

What is adherence in phagocytosis?

Attachment of phagocyte to pathogen

What is ingestion?

Engulfing of pathogen by phagocyte

What is digestion in phagocytosis?

Breakdown of pathogen inside phagocyte

What are the main steps of inflammation?

Vasodilation, increased permeability, phagocyte migration, tissue repair

What is vasodilation?

Widening of blood vessels to increase blood flow

Why is vessel permeability increased during inflammation?

Allows immune cells and fluids to enter tissues

What causes fever?

Pyrogens such as bacterial toxins and immune signals

What are pyrogens?

Substances that trigger fever

What happens during the chill phase of fever?

Vasoconstriction and shivering increase body temperature

What happens when fever breaks (crisis)?

Perspiration, vasodilation, and decreased metabolic rate

Why is fever beneficial?

Inhibits microbial growth and enhances immune response

What is immunity?

The ability of the body to resist pathogens using specific defenses like antibodies

What is an antigen?

A foreign substance that triggers an immune response

What is an antibody?

A protein produced by B cells that binds specific antigens

What are the four types of immunity?

Naturally acquired active, naturally acquired passive, artificially acquired active, artificially acquired passive

What is naturally acquired active immunity?

Immunity from infection and recovery (body produces its own antibodies)

What is naturally acquired passive immunity?

Immunity from antibodies passed from mother to child

What is artificially acquired active immunity?

Immunity from vaccination

What is artificially acquired passive immunity?

Immunity from injected antibodies (immediate but temporary)

What is herd immunity?

Protection of a population when many individuals are immune, reducing disease spread

What is the first step of the immune response?

Recognition of antigen as foreign

Which cells recognize antigens?

Lymphocytes

What happens during immune activation?

B cells undergo clonal selection and multiply

What is clonal selection?

Process where specific B cells are activated and replicate

What do plasma cells do?

Produce antibodies

What are memory cells?

Long-lived cells that provide faster response upon re-exposure

What is the primary immune response?

First exposure to antigen; slower and weaker response

What is the secondary immune response?

Faster, stronger response due to memory cells