exam3 ch12

A collection of flashcards covering key concepts related to host defenses in the immune system.

Innate Immunity

The first line of defense composed of anatomical and physiological barriers that prevent infection.

Adaptive Immunity

Specific host defenses developed uniquely for each microbe through specialized white blood cells; changes over time

self

what belongs to your body

non-self

what doesn’t belong to your body

Antigens

any molecule/piece of molecule unique to a cell/molecule

Pathogen-associated molecular patterns (PAMPs)

patterns/groups recognized by the immune system because they are associated with pathogens

the lymphatic system

system that is parallel to the circulatory system; major part of the immune sys.

lymph

fluid that carries immune cells & molecules; produced in lymph nodes

Phagocytosis

The process by which cells ingest and eliminate microbes and dead cells.

RBCs

carry O2; only found in circulatory sys.

WBCs

cells that serve for immune function; can be granulocytes or agranulocytes

Granulocytes

A type of white blood cell characterized by granules in their cytoplasm which are for foreign cell destruction.

Agranulocytes

A type of white blood cell that lacks visible granules; important for adaptive immune sys./producing antibodies

Cytokines

Chemicals used by cells to communicate with each other and regulate immune responses.

1. physical barriers

2. chemical barriers

3. microbiological barriers

What are the 3 types of barriers in the innate immune sys.

physical barriers: wall

mechanical barriers: requires movement

What are the 2 types of physical defenses?

1. skin

2. hair

3. mucous membranes

What are 3 examples of physical barriers?

1. mucociliary escalator

2. urination

3. tears and sweat

What are 3 examples of mechanical barriers?

skin & hair

What are the most important physical barriers?

epidermis

outer layer of skin and hair consisting of tightly packed dead epithelial cells and keratin (protein in nails & hair)

the dead skin & hair cells continuously sloughing off, removing microbes

When it comes to skin and hair, what is an example of mechanical barrier?

mucous membrane

lines many of the body’s “outer” surfaces (surfaces that touch outside air); consists of tightly packed epithelial cells that secrete mucus

mucus

sticky substance that catches microbes

mucociliary escalator

mechanical barrier that includes ciliated cells moving in a wave-like motion to mechanically move microbes out of the body

cystic fibrosis

What develops when the mucociliary escalatory stops working

1. tears

2. urination

3. sweat

4. coughing/sneezing

5. sloughing off dead skin cells

6. mucociliary escalator

What are 6 examples of mechanical defenses that physically wash microbes away from the body

Inflammation

The reaction to tissue injury that attracts immune components and promotes healing.

chemical defenses

chemical substances that inhibit or kill microorganisms in a non-specific way

1. sebum-fatty waxy substance (no water)

2. lactic acid in sweat (low pH)

What are 2 of the skin’s chemical defenses?

destroys microbes through enzymes

What is mucous & tears’ chemical defense?

Monocyte

A type of agranulocyte that differentiates into macrophages and dendritic cells.

Basophil

A type of granulocyte involved in inflammatory reactions.

Neutrophil

A type of granulocyte that is a key component of the innate immune response.

Mast Cell

A cell that releases chemicals like histamine during inflammatory responses.

Eosinophil

A granulocyte that plays a role in fighting parasitic infections.

B Cells

Lymphocytes that develop into plasma cells to produce antibodies.

T Cells

Lymphocytes involved in cell-mediated immune responses.

Natural Killer (NK) Cells

A type of lymphocyte that targets and kills infected or cancerous cells.

Gamma-delta T Cells

A type of T cell with unique T-cell receptors; involved in innate immune responses.

Dendritic Cells

Professional antigen-presenting cells that activate T cells.

Chemotaxis

The movement of cells toward chemical signals.

Diapedesis

The process by which white blood cells move out of the bloodstream and into tissues.

Cilia

Hair-like structures that help move mucus and trapped microbes out of the respiratory tract.

Mucous Membranes

Layers of epithelial cells that secrete mucus to protect body surfaces.

Sebum

An oily substance produced by sebaceous glands that helps protect skin.

Lysozyme

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

GALT

Gut-associated lymphoid tissue that plays a role in immune responses within the gastrointestinal tract.

Vasodilators

Substances that widen blood vessels to increase blood flow.

Vasoconstrictors

Substances that narrow blood vessels, reducing blood flow.

Interleukins

A group of cytokines that are crucial for cell signaling in the immune system.

TNF-β

Tumor necrosis factor beta, a cytokine involved in systemic inflammation.

Erythropoietin

A hormone that stimulates the production of red blood cells.

Normal Flora

The beneficial microorganisms normally present in the body.

Antimicrobial Peptides

Short proteins that can kill bacteria and other pathogens.

Fever

An increase in body temperature typically above 100.4 °F (38 °C) as a response to infection.

Pyrogen

A substance that induces fever.

Endogenous Pyrogens

Cytokines produced within the body that cause fever.

Exogenous Pyrogens

Substances originating outside the body that can induce fever.

Acid in Stomach

A chemical barrier that kills many pathogens ingested with food.

Lactic Acid

An organic acid produced in muscles and by bacteria that helps inhibit pathogen growth.

Interferons

Cytokines produced in response to viral infections that help limit the spread of viruses.

Complement System

A part of the immune system that enhances the ability of antibodies and phagocytes to clear pathogens.

Skin

The body's outer barrier that prevents microbial entry.

Tears

Fluid that washes away foreign particles and contains antimicrobial agents.

Urination

The process that helps wash away pathogens from the urinary tract.

Sweat

Fluid secreted by sweat glands that can inhibit microbial growth due to its chemical composition.

Coughing/Sneezing

Reflex actions that expel irritants from the respiratory tract.

Sloughing of Dead Skin Cells

The natural shedding of skin that removes attached microbes.