Microbiology Chapter 14 Test 4 Flashcards

What are the 3 lines of defense?

The first line is physical and chemical barriers

the second line is internal innate defenses

the third line is adaptive immunity.

Which lines of defense are innate or acquired?

The first and second lines are innate (present at birth)

the third line is acquired.

Which lines of defense are specific or nonspecific?

The first and second lines are nonspecific

the third line is specific.

What does the first line of defense include?

Physical and chemical barriers, including skin and mucous membranes.

What does the first line of defense prevent?

It prevents microorganisms from entering the body's internal environment.

What is involved in the second line of defense?

Internal protective cells and fluids, including recognition, inflammation, phagocytosis, interferon, and complement.

What physical barriers are involved in the first line of defense?

Skin, mucous membranes, epithelial and endothelial cell junctions, nasal hairs, and mucus.

How does the skin act as a physical barrier?

Dead epidermal cells packed with keratin create a tough surface that resists damage and inhibits microbial growth.

How do mucous membranes protect the body?

They line the respiratory, digestive, and urogenital tracts

mucus traps microbes and debris and protects the cells underneath.

What mechanical actions help protect the body?

Skin-cell shedding, expulsion of mucus, intestinal peristalsis that removes feces, and the flushing action of urine and tears.

Are blinking and urination listed in the lecture notes as mechanical defenses?

Urination is listed, but blinking is not specifically listed in the notes.

What is the mucociliary escalator?

Ciliated cells move mucus containing trapped debris and microbes up and away from the lungs.

What are examples of first-line chemical defenses?

Sebum, oleic acid, lysozyme, lactoperoxidase, stomach acid, intestinal enzymes, bile, antimicrobial peptides, acidic urine, acidic vaginal secretions, and chemicals in sweat and tears.

Are first-line chemical defenses specific or nonspecific?

They are nonspecific chemical defenses.

What does lysozyme do?

It is an enzyme that breaks down bacterial cell walls by cleaving bonds in the cell-wall material

it is especially effective against Gram-positive bacteria.

Where can lysozyme be found?

Tears, mucus in the esophagus and respiratory tract, and secretions from intestinal Paneth cells.

What is an endogenous chemical mediator?

A chemical mediator produced by human body cells, such as sebum.

What is an exogenous chemical mediator?

A chemical mediator produced by microbes, including members of the body's microbiome, rather than human cells.

What is immunology?

The study of the biological, chemical, and physical events involved in the function of the immune system.

What is the immune system?

A large, complex network of cells and fluids that extends throughout the body's organs and tissues.

What does the immune system include?

Organs, tissues, cells, body fluids, the bloodstream, and the lymphatic system.

What are the three jobs of the immune system?

Surveillance (scouting for foreign material), recognition (distinguishing self from foreign material), and attack and destruction of foreign invaders.

What does non-self mean?

Foreign material that does not belong to the body.

What does self mean?

The normal cells of the body.

What are pathogen recognition receptors (PRRs)?

Receptors on white blood cells that recognize pathogen-associated molecular patterns (PAMPs). Toll-like receptors are an example.

What are pathogen-associated molecular patterns (PAMPs)?

Molecules shared by microorganisms that can be recognized by the immune system.

What is the RES?

The reticuloendothelial system: a network of connective-tissue fibers that connects cells and meshes with connective tissue around organs.

What inhabits the RES?

Phagocytic cells, especially macrophages, that can attack and ingest microbes that pass the first line of defense.

What is whole blood?

Whole blood consists of plasma and formed elements (blood cells).

What is plasma?

The liquid portion of blood, made mostly of water and containing proteins, clotting factors, hormones, gases, and other chemicals.

What is the difference between blood and plasma?

Blood includes plasma and formed elements

plasma is only the liquid portion. Serum is the liquid remaining after a clot forms, without clotting factors.

What is hemopoiesis?

The process of forming blood cells.

Where does hemopoiesis occur?

In red bone marrow.

What are the three major divisions of formed blood elements?

Erythrocytes (red blood cells), thrombocytes (platelets), and leukocytes (white blood cells).

Which blood cell is most numerous?

Erythrocytes, or red blood cells.

Which blood cell lacks a nucleus when mature?

The erythrocyte, or red blood cell.

What are the two divisions of leukocytes?

Granulocytes and agranulocytes.

What are the three types of granulocytes?

Neutrophils, eosinophils, and basophils.

Which granulocyte is most numerous?

Neutrophils, making up about 55–90% of leukocytes according to the notes.

Which granulocyte is least numerous?

Basophils, making up about 0.5% of leukocytes.

Which granulocytes are phagocytic?

Neutrophils are important phagocytes

eosinophils are weak phagocytes.

Which granulocyte releases histamine?

Basophils release histamine and contribute to allergic reactions and inflammation. Mast cells in connective tissue also release histamine.

Which granulocyte increases during worm or parasite infections?

Eosinophils.

Which cells respond during allergic reactions?

Basophils release histamine during immediate allergic reactions

eosinophils are also attracted to antigen-antibody reactions.

What are the two agranulocytes?

Lymphocytes and monocytes.

Which agranulocyte is involved in specific immunity?

Lymphocytes. B cells produce antibodies, and T cells help regulate immune functions and kill foreign cells.

What are the two cell types that can develop from monocytes?

Macrophages and dendritic cells.

What do monocytes become after leaving a blood vessel?

They can differentiate into macrophages or dendritic cells, depending on the signals they receive.

What is the process of a white blood cell squeezing out of a blood vessel called?

Diapedesis.

What do dendritic cells do?

They trap pathogens and participate in immune reactions

they are concentrated in the skin and the linings of mucous membranes.

What is chemotaxis?

The ability of cells to migrate toward a chemical stimulus, usually at a site of inflammation or infection.

How is lymphatic fluid formed?

It forms when blood components move out of blood vessels into extracellular spaces and enter lymphatic circulation.

What does lymph transport?

White blood cells, fats, cellular debris, and infectious agents.

How does lymph move through lymphatic vessels?

It is moved by contractions of skeletal muscles

lymphatic vessels do not have a heart-like pump.

What direction does lymph move?

It flows in one direction toward the heart and eventually returns to the bloodstream.

What is the purpose of primary lymphatic organs?

They are the sites where lymphocytes originate and mature.

What is the purpose of secondary lymphatic organs?

They are locations where lymphocytes encounter microbes and immune responses take place.

What are the two primary lymphatic organs?

Bone marrow and thymus gland.

What happens in bone marrow?

It produces all blood cells and is a site of lymphocyte origin and maturation.

What happens in the thymus gland?

It is the site where T cells mature.

What is unique about the size of the thymus gland?

It grows and is highly active until puberty, then begins to shrink.

What are lymph nodes?

Small, encapsulated, bean-shaped organs located along lymphatic channels and large blood vessels.

What happens in lymph nodes?

They filter materials that enter the lymph and provide locations for immune reactions.

What is the spleen?

The largest mass of lymphatic tissue

it is structurally similar to a lymph node and filters circulating blood.

What happens in the spleen?

It removes worn-out red blood cells and pathogens from the blood.

What does GALT stand for?

Gut-associated lymphoid tissue

clusters of lymphoid tissue in the gut.

What does MALT stand for?

Mucosa-associated lymphoid tissue.

What does SALT stand for?

Skin-associated lymphoid tissue.

What is inflammation?

The body's response to injury that helps destroy microbes and limit their spread.

What are the roles of inflammation?

It attracts immune cells and chemicals to injury, helps repair tissue and clear harmful substances, and destroys or blocks microbes from spreading.

What does rubor mean?

Redness caused by increased circulation and vasodilation in injured tissue.

What does calor mean?

Heat caused by increased blood flow to the injured area.

What does tumor mean in inflammation?

Swelling caused by fluid escaping into tissues as blood vessels become more permeable.

What does edema mean?

Swelling caused by excess fluid collecting in tissues.

What does dolor mean?

Pain caused by stimulation of nerve endings.

What causes redness during inflammation?

Vasodilation and increased circulation, partly in response to histamine released by mast cells.

What causes heat during inflammation?

Increased blood flow to the injured area, bringing neutrophils to begin phagocytosis.

What causes swelling during inflammation?

Increased blood-vessel permeability allows fluid to escape into the tissue.

Who are the first responders during inflammation?

Neutrophils are the first white blood cells to leave blood vessels and respond at the site.

Who are the cleanup crew during inflammation?

Macrophages, lymphocytes, and fibroblasts help clear debris and support cleanup and repair.

What is a fever?

An abnormally elevated body temperature.

What is responsible for maintaining core body temperature?

The hypothalamus sets the body's core temperature.

What are exogenous pyrogens?

Pyrogens that come from products of infectious agents.

What are endogenous pyrogens?

Pyrogens released by the body's cells, including monocytes, neutrophils, and macrophages during phagocytosis. Examples include interleukin-1 (IL-1) and tumor necrosis factor (TNF).

What would lipid A (endotoxin) be considered?

An exogenous pyrogen, because it is part of a bacterial product. The notes do not specifically mention lipid A, so this answer is based on its classification as a microbial endotoxin.

What are the general activities of phagocytes?

They survey tissues for microbes, particles, and dead or injured cells

ingest and eliminate these materials