Chapter 14 - An Introduction to Host Defenses

Skin is protected by the insoluble protein _____.

Keratin

_____ are participants of the specific immune response and are characterized as small, spherical cells with uniformly staining dark, round nuclei.

Lymphocytes

_____ react to foreign substances in the third line of defense.

Lymphocytes

The second most predominating type of leukocyte in circulation are _____.

Lymphocytes.

Organs lined with mucous membranes contain _____ to respond to the constant flux of microbes through these portals of entry.

MALT

A large, phagocytic white blood cell, derived from a monocyte, that leaves the circulation and plays a role in specific immune reactions while residing in tissues is called a(n) _____.

Macrophage

An example of genetic differences in susceptibility to disease is the sickle-cell trait that confers resistance to _____.

Malaria

What activates the lectin complement pathway?

Mannans

A non-motile cell bound to connective tissue along capillaries and contain granules that store (and release) mediators of inflammation and allergy such as histamine is known as a(n) _____ cell.

Mast

_____ are non-motile cells that are bound to connective tissue along capillaries that contain granules that store inflammatory mediators.

Mast cells

What is engulfed by phagocytes?

Microbes, dust, and dead cells

The third line of defense is a powerful system of specific responses to infectious agents called _____ or _____ immunity.

Acquired Adapted

The third line of defense is a powerful system of specific responses to infectious agents called _____ or ______ immunity.

Adaptive Acquired

Enzymatic digestion of bacteria inside of a phagolysosome can occur within 30 _____.

Minutes

When viewing leukocytes under a light microscope, staining with a hematologic stain cells produces some cells with granular structures in the cytoplasm. Leukocytes that do not have visible cytoplasmic granules under these conditions are called _____.

Agranulocytes

White blood cells with an unlobed, rounded nucleus and the absence of tiny inclusions in their cytoplasm are referred to as _____.

Agranulocytes

Acute inflammatory responses last from a few _____ to _____.

Minutes Hours

How lond do most acute inflammatory responses last?

Minutes to hours

Phagocytes have receptors that recognize pathogen-associated _____ _____ (PAMPS) on microbes.

Molecular patterns

A _____ is a large agranulocyte that differentiates into macrophages and dendritic cells.

Monocyte

What cell type makes up 3-7% of circulating leukocytes?

Monocytes

What are some agranulocytic white blood cells?

Monocytes Lymphocytes

Which white blood cells are agranulocytic?

Monocytes Lymphocytes

All organs and tissues contain a network of fibers and macrophages called the _____ system.

Mononuclear phagocyte

The __________ system is a network of fibers and macrophages that permeates the tissues of the body.

Mononuclear phagocyte

In _____ immunity, a type of adaptive immune response, specialized B cells secrete antibodies into the body fluids.

Humoral

What type of immunity mainly involved the action of B cells?

Humoral

What are some phagocytic digestion mechanisms?

Hydrolytic enzymes Cationic proteins Respiratory burst Nitric oxide

Human body temperature is normally maintained by the _____.

Hypothalamus

The _____ controls body temperature, hunger, thirst, fatigue, sleep, and circadian rhythms.

Hypothalamus

_____ is the study of all features of the body's response to, and defense against, infectious microbes, cancer, and allergy

Immunology

_____ is the study of all features of the body's sending and third line of defenses.

Immunology

Interferons are produced and secreted only by virally-_____ cells.

Infected

Trauma, infection, or an immune response can trigger a nonspecific immune response called _____.

Inflammation

_____ is a reaction to any traumatic event in the tissues that restores homeostasis.

Inflammation

The sec on cline of host defenses includes fever, _____, _____, _____, and _____.

Inflammation Phagocytosis Interferon Complement

In addition to responding to eukaryotic pathogens such as fungi and helminths, eosinophils also function in what?

Inflammatory reactions Allergic reactions

When a toll-like receptor binds to a foreign molecule, what is stimulated?

Inflammatory response Activity of lymphocytes

What is the correct order for the stages of complement activation?

Initiation Amplification Polymerization Membrane attack

_____ stimulates cells to produce antiviral proteins.

Interferon

_____ are small protein molecules produced by certain leukocytes and tissue cells in response to viral infection.

Interferons

Name some endogenous pyrogens.

Interleukin-1 TNF

_____ fluid is a plasma-like fluid that moves in and out of tissues, but does not contain red blood cells.

Interstitial

What is the purpose of vasodilation?

It increase blood flow to the injured area

True or False?: Complement action enhances inflammation.

True

True or False?: Interferon activates natural killer cells, T cells, B cells, and phagocytes.

True

True or False?: The membrane attack complex forms with all types of complement activation.

True

True or False?: Interferon is host-specific but not virus-specific.

True. Interferons can work against many types of viruses

The killing of microbes in the phagolysosome by products of oxygen metabolism is referred to as the _____-_____ system.

Oxygen-dependent

Phagocytes migrate to regions of inflammation in response to chemical messengers that have been released by phagocytes at the infection site that have detected specific microbial molecular patterns called _____.

PAMPS

Molecules shared by many microbes that act as "red flags" for white blood cells are known as _____.

PAMPs

The toll-like receptors found on phagocytes react with what structures of pathogenic microbes?

PAMPs

PRRs and TLRs interact with molecules on the surfaces of pathogens known as _____-_____ _____ _____.

Pathogen-associated molecular patterns

In addition to phagocytosis and initiation of inflammation, white blood cells have the capacity to discover foreign substances using surface receptors known as _____.

Pattern recognition receptors

Toll-like receptors are found within the cell membrane of _____.

Phagocytes

The main role of neutrophils is _____.

Phagocytosis

What is the main role of neutrophils?

Phagocytosis

What is the process in which foreign particles or cells are engulfed and then digested by specific immune cells?

Phagocytosis

The binding of PAMPs to TLRs results in stimulation of _____ and _____.

Phagocytosis Inflammation

The phagocyte initially encloses ingested materials in a vacuole called a(n) _____.

Phagosome

A(n) _____ cell is derived from an activated B lymphocyte and produces and secretes antibodies.

Plasma

What contains clotting factors, hormones, nutrients, dissolved gases, and wastes?

Plasma

_____ cells are derived from an activated B lymphocyte and produce and secrete antibodies.

Plasma

_____ is the fluid portion of the blood that carries proteins, nutrients, and clotting factors; and in which blood cells are normally suspended.

Plasma

_____ is the clear fluid from blood that contains clotting proteins, whereas _____ is the clear fluid from clotted blood that does not contain clotting proteins.

Plasma Serum

Formed elements in the blood that are involved in hemostasis and blood clotting are called _____.

Platelets

_____ are formed elements in the blood that are involved in hemostasis and blood clotting.

Platlets

Hematopoiesis occurs in which areas at some stage of life?

Red bone marrow Lymphatic organs Liver Yolk sac

What are the main functions of the inflammatory response?

Repair damaged tissues Destroy microbes and block their further invasion Mobilization and attraction of immune components to the site of infection or trauma

Ciliated epithelium and nasal hair are first-line defense adaptations that guard which body tract?

Respiratory

The _____ system, _____ fluid, _____, and lymphatic system are all body compartments that participate in immune function.

Reticuloendothelial Extracellular Blood

Lymphocytes are mainly involved in which host defense line?

Third line of defense

The function of the _____ gland is the maturation of T cells.

Thymus

What is the function of the phagolysosome?

To digest the ingested particles or cell

_____-_____ receptors are pattern recognition receptors found on macrophages and dendritic cells that recognize common molecules patterns on microbes and stimulate the inflammatory response.

Toll-like

The protein receptors found on macrophages and dendritic cells that recognize molecules on microbes and stimulate the inflammatory response are called _____.

Toll-like receptors

Chemotactic factors are cytokines that do what?

Attract WBCs to the site of inflammation

What are thrombocytes involved in?

Clotting Inflammation Hemostasis

What is contained in blood plasma?

Clotting factors Hormones Nutrients Wastes Dissolved gases

How does the resident biota act as the first line of defense?

Competing for nutrients Blocking access of pathogens Altering pH of environment

The _____ system enhances the ability of antibodies and phagocytic cells to clear pathogens from an organism.

Complement

The _____ system is a cascade of serum proteins that form a membrane attack complex.

Complement

A(n) _____ is a chemical substance produced by blood cells and tissue cells that regulated development, inflammation, and immunity.

Cytokine

Peptides produced by cells and tissues that damage cell membranes and lyse bacteria and fungi are _____.

Defensins

_____ are antimicrobial peptides produced by various tissues that damage cell membranes of bacteria and fungi.

Defensins

A line of phagocytic, antigen-presenting cells that are named for their long, thin cell processes are known as _____.

Dendritic cells

_____ is the shedding of the outermost layer of epithelial cells.

Dequamation

_____ is a peptide released by skin cells that breaks down bacterial membranes, and causes lysis of bacterial cells.

Dermicidin

The process of _____ refers to the transmigration of white blood cells out of capillaries into deeper tissues.

Diapedesis

The transmigration of white blood cells across capillary walls into deeper tissues is called _____.

Diapedesis

How does lymph fluid differ from blood?

Does not contain red blood cells

Accumulation of exudate that gives rise to local swelling and hardness is known as _____.

Edema

The complement system is a cascade of serum proteins that, when activated, results in what?

Enhancement of inflammation Enhancement of phagocytosis Formation of membrane attack complexes

Immunologic responses to fungal and helminth worm infections, allergy, and inflammatory reactions are carried out by _____.

Eosinophils

_____ are the granulocytes that are mostly involved in immunologic responses to fungal and helminth worm infections, allergy, and inflammatory reactions.

Eosinophils

"_____" is the scientific term for red blood cells.

Erythrocyte

Red blood cells are called _____.

Erythrocytes

_____ are the predominant type of cells circulating in the blood.

Erythrocytes

What are the products of infectious agents?

Exogenous pyrogens

Protein-rich fluid that builds up in the extracellular spaces during inflammation is called _____.

Exudate

During inflammation, a protein-rich fluid called _____ moves from the venues into the extracellular space, resulting in a swelling of tissue called _____.

Exudate Edema

True or False?: Interferons only bind to virally infected host cell receptors.

False

True or False?: Macrophages develop from activated neutrophils.

False

What are the functions of the spleen?

Filtration of pathogen from the blood Remove worn-out RBC from circulation

What are the roles of the lymph nodes?

Filtration of the lymphatic fluid Provision of immune cells

Coughing and sneezing are _____ line defenses that expel air from the respiratory tract.

First

What is correct order of events in phagocytosis?

1. Chemotaxis 2. Engulfment 3. Phagolysosome formation 4. Killing of bacterial cells 5. Release of cellular debris

List the predominance of circulating leukocytes from most to least.

1. Neutrophils 2. Lymphocytes 3. Monocytes 4. Eosinophils 5. Basophils

There are _____ major types of interferon.

3

There are how many different types of complement activation pathways?

3

Surface antigens activate the ______ complement pathway.

Alternative

What occurs as monocytes are transformed into macrophages?

An increase in size Enhancement of lysosomes

Plasma contains globulin proteins, which include _____.

Antibodies

What activates the alternative complement pathway?

Antigens

As part of the nonspecific chemical defense, semen contains a(n) _____ _____ that inhibits bacteria.

Antimicrobial chemical

What cell types can be activated/stimulated by interferon?

B cells Neutrophils Macrophages

Eosinophils target _____, _____, and _____.

Bacteria Helminths Fungi

What is considered to be "nonself"?

Bacteria Viruses Fungi

Along with mast cells, _____ are types of granulocytic leukocytes that mediate immediate allergies by releasing histamine.

Basophil

Which cell type has a pale-staining, constricted nucleus and contains granules with potent chemical mediators such as histamine?

Basophil

_____ are motile granulocytes that function in inflammatory events and allergies by releasing histamine.

Basophils

The digestive juices and _____ of the intestines provide nonspecific chemical defense against most microbes.

Bile

What component of the intestinal contents can be destructive to microbes?

Bile

What are the body compartments that participate in the immune system?

Bloodstream Lymphatic system Extracellular fluid Reticuloendothelial system

The fever response is defined as an abnormally elevated _____ _____.

Body temperature

T-lymphocytes directly attacking foreign or abnormal cells is known as _____ immunity.

Cell-mediated

Inborn, nonspecific defenses include _____, _____, and _____ barriers.

Chemical Genetic Physical

Substances known as _____ are released by cells in an injured area that act on endothelial cells and smooth muscle cells.

Chemical mediators Cytokines

_____ factors (chemokines) are cytokines that stimulate the movement of whit blood cells.

Chemotactic

_____ factors (chemokines) are cytokines that stimulate the movement of white blood cells.

Chemotactic

Phagocyte migration to inflammation areas when attracted by stimulants from both parasite and host tissue is an example of _____.

Chemotaxis

The process of _____ refers to the migration of WBCs toward chemical stimuli from an injured area.

Chemotaxis

The process of ______ refers to the migration of WBCs toward chemical stimuli from an injured area.

Chemotaxis

_____ is the migration of WBCs to the site of infection or trauma in response to chemical messages.

Chemotaxis

_____ inflammation can last anywhere from a few days to years as opposed to acute inflammation that lasts for minutes to hours.

Chronic

_____ inflammation can lead to host tissue damage or destruction.

Chronic

In the respiratory tract, _____ on the epithelium convey trapped foreign particles entrapped in mucus towards the pharynx for removal.

Cilia

The _____ complement pathway is activated by antigen-antibody complexes.

Classical

Serous fluid exudate is _____ while pus is opaque due to the presence of cells.

Clear

What associated lymphoid tissue provides immune function against intestinal pathogens and is a significant source of some types of antibodies?

GALT

What type of interferon regulates macrophages and lymphocytes?

Gammma

All interferons bind to surface receptors on target cells and induce changes in _____ expression.

Gene

What are the two groups in which leukocytes are divided into?

Granulocytic Agranulocytic

_____ is the process by which all blood cells are formed in bone marrow.

Hematopoiesis

Specialized macrophages called _____ migrate to certain tissues and remain there for their life span.

Histiocytes

The membrane attack complex creates _____ in the membranes or viral envelopes of pathogen, resulting in their eventual lysis.

Holes

Mannans activate the _____ complement pathway.

Lectin

The primary infection-fighting blood cells are called _____.

Leukocytes

_____ are primary infection-fighting blood cells, also known as white blood cells.

Leukocytes

Pluripotent stem cells can differentiate into what cell types?

Leukocytes Erythrocytes Thrombocytes

Lymph is transported through a system of _____ vessels.

Lymphatic

The _____ system is a system of vessels and organs that serve as sites for the development of immune cells, immune surveillance, and immune reactions.

Lymphatic

The spleen, thymus, lymph nodes, and GALT are all components of the _____ system.

Lymphatic

Hematopoiesis occurs in what areas at some stage of life?

Lymphatic organs Yolk sac Red bone marrow Liver

The circulatory system consists of the organs and tissues of both the _____ and _____.

Lymphatic system Circulatory system proper

Which cells are elevated in viral infections?

Lymphocytes

Which leukocytes are composed of small spherical cells that are involved in the specific immune response?

Lymphocytes

Moist _____ membranes line the eye and the respiratory, digestive, and urinary tracts.

Mucous

The flow of what substances carry microbes away from the respiratory tract?

Mucus Saliva

What adaptation guards the respiratory tract from the largest particles?

Nasal hair

Structures that comprise some of the first line defenses in the respiratory tract are _____ _____ and _____ epithelium.

Nasal hair Ciliated

What cell types are involved in the third line of host defense?

Natural killer cells Lymphocytes

Most aggregations of lymph nodes are found in the _____, _____, and _____ areas.

Neck Groin Armpit

Where are the sites of the major lymph nodes?

Neck, Groin, Armpit

An elevated number of white blood cells, in particular the _____, are a sign of bacterial infection.

Neutrophils

What type of leukocyte spends most of its life in the tissues serving as a major phagocytic cell?

Neutrophils

Which cells are elevated in bacterial infections?

Neutrophils

Which cells are the first phagocytes to act in inflammation?

Neutrophils

Which white blood cells are the primary components of pus?

Neutrophils

_____ are also called polymorphonuclear leukocytes or PMNs.

Neutrophils

_____ make up 55-90% of circulating leukocytes.

Neutrophils

What cell types are activate/stimulated by interferon?

Neutrophils B cells Macrophages

Which leukocytes are a granulocytes?

Neutrophils Basophils Eosinophils

What cell types are the major phagocytic cells of the immune system?

Neutrophils Monocytes Macrophages

Neutrophils are also called _____ neutrophils or PMNs.

Polymorphonuclear

What are some characteristics of B lymphocytes?

Produce antibodies when activated Move freely between lymphoid organs and connective tissue Mature in the bone marrow

Interferons stimulate cells to do what?

Produce antiviral proteins

Once a phagocyte has made contact with foreign substances or damaged material, it extends _____ to engulf the particles into a pocket for internalization.

Pseudopods

_____ is opaque matter formed during inflammation that consists of serum exudate, tissue debris, leukocytes, and microorganisms.

Pus

Pus-forming bacteria are also called _____ organisms.

Pyogenic

_____ is the ability to cause pus.

Pyogenic

A _____ is a circulating chemical substance that resets the hypothalamus to a body higher temperature setting.

Pyrogen

_____ is the ability to cause fever.

Pyrogenic

Circulating substances that can trigger fever are called _____.

Pyrogens

The flow of fluids such as _____ and _____ carriers microbes away from the respiratory tract.

Saliva Mucus

_____ secretions can have an antimicrobial effect.

Sebaceous

The host inflammatory response is a component of the _____ line of defense.

Second

Natural markers of the body that are recognized by the immune system are called _____.

Self

Normal cells of the body, classified as "_____", do not normally trigger an immune response.

Self

It is critical for the immune system to differentiate between _____ and _____.

Self Nonself

The clear fluid that remains after clotting proteins are removed from blood is called _____.

Serum

_____ is the clear fluid from clotted blood often used in immune testing and therapy.

Serum

Lymph moves through lymphatic vessels only through contraction of _____ muscles around lymphatic ducts.

Skeletal

The _____ provides an impervious and waterproof barrier to microbes.

Skin

What host barrier offers protection against microorganisms due to the presence of sebum, which has a high fatty acid content and acidic pH?

Skin

What is the first line of defense?

Skin

_____ is/are an external, confluent protective barrier.

Skin

Some pathogens are capable of infecting only one _____ of host.

Species

The _____ is similar in function to a lymph node except it filters blood instead of lymph.

Spleen

The pluripotent, undifferentiated cells in the bone marrow that give rise to the formed elements are called _____ cells.

Stem

What are the benefits of fever?

Stimulation of host Immune system Stimulation of host hematopoiesis Increased host metabolism Increased levels of phagocytosis Inhibited growth of temperature sensitive microbes

Which body site contains hydrochloric acid that inhibits many microbes?

Stomach

The direct attack of foreign or abnormal cells by _____-lymphocytes is known as cell-mediated immunity.

T

_____-lymphocytes mature in the thymus gland whereas _____-lymphocytes mature in the bone marrow.

T B

Microbes and other unwanted materials are flushed from the surface of the eyes by the flow of _____.

Tears

Where is the hydrolytic enzyme lysozyme found?

Tears Salive Sebum

What is the main important role of the reticuloendothelial system in immune function?

The provision of a passageway within and between tissues

The flow of lymph in lymphatic vessels is _____.

Unidirectional

Where is the spleen located?

Upper left abdomen

Mucosal-associated lymphoid tissue (MALT) responds to microbes entering through which body systems?

Urinary Respiratory Gastrointestinal

The urogenital tract receives partial protection from microbes through the flushing action of _____ flow through the urethra.

Urine

The _____ of monocytes contains stored digestive enzymes.

Vacuoles

_____ is a term for the widening of blood vessels that increases blood flow to an injured area.

Vasodilation

_____ is the main fluid in plasma.

Water

The liquid connective tissue consisting of erythrocytes, leukocytes, and platelets suspended in plasma is called __________.

Whole blood

_____ _____ is a liquid connective tissue consisting of erythrocytes, leukocytes, and platelets suspended in plasma.

Whole blood