TEAS 7 Immune System

INNATE IMMUNE SYSTEM

Is the innate system specific or nonspecific?

nonspecific because we are born with it

What is the innate system?

Nonspecific first line of defense against pathogens that is present at birth

Is there potential for the innate system to "learn" from previous pathogens or adapt to new threats?

NO

What are the 2 barriers to infection in the 1st line of defense of the innate system?

Mechanical and chemical barriers

What are the 1st barriers of infection of the innate immune system?

Mechanical barriers:

- skin

- mucous membranes

What is the 2nd barrier of infection of the innate immune system?

Chemical barriers:

- stomach acid (low pH of gastric juice)

- lysozymes in tears

- interferons that block viral replication

- antimicrobial proteins (defensins, collectins, complements)

- phagocytes engulf pathogens

- destruction of infected cell by natural killer cell

INNATE IMMUNE SYSTEM CELLS

Neutrophils

(innate immunity)

Most of white blood cells in the bloodstream

Usually first to arrive at the site of infection

Chase pathogens using chemotaxis

Phgocytosis

Most of white blood cells in the bloodstream

Usually first to arrive at the site of infection

Chase pathogens using chemotaxis

Neutrohils

(innate immunity)

Eosinophils

(innate immunity)

Regulate inflammatory responses

Release chemicals that kill foreign invaders often parasite worms

Regulate inflammatory responses

Release chemicals that kill foreign invaders often parasite worms

Eosinophils

(innate immunity)

Mast cells

(innate immunity)

Found in connective tissue

Release histamine to promote inflammation and heparin to inhibit clotting

Found in connective tissue

Release histamine to promote inflammation and heparin to inhibit clotting

Mast cells

(innate immunity)

Basophils

(innate immunity)

Circulate in the blood before entering tissues

Release histamine to promote inflammation and heparin to inhibit clotting

Circulate in the blood before entering tissues

Release histamine to promote inflammation and heparin to inhibit clotting

Basophils

(innate immunity)

Macrophages

(innate immunity)

Large WBCs that engulf debris and pathogenic microorganisms

Phagocytosis

Function as antigen presenters to effector T cells

Large WBCs that engulf debris and pathogenic microorganisms

Function as antigen presenters to effector T cells

Macrophages

(innate immunity)

Dendritic cells

(innate immunity)

Activate naive T cells

Phagocytosis

T cells that have not yet encountered their antigen

Activate naive T cells

T cells that have not yet encountered their antigen

Dendritic cells

(innate immunity)

Dendritic cells

specialized white blood cells that patrol the body searching for antigens that produce infections

Natural killer cells

(innate immune system)

NOT phagocytes

Destroy cells that have been infected with a pathogen by binding to them and releasing granzymes that trigger apoptosis

NOT phagocytes

Destroy cells that have been infected with a pathogen by binding to them and releasing granzymes that trigger apoptosis

Natural killer cells

(innate immune system)

What is naturally acquired active immunity

Natural

Individual is exposed and builds immunity to a pathogen WITHOUT an immunization

Individual is exposed and builds immunity to a pathogen WITHOUT an immunization

naturally acquired active immunity

What is artificially acquired active immunity?

Artificial

Individual is exposed and builds immunity to a pathogen by a VACCINE

Individual is exposed and builds immunity to a pathogen by a VACCINE

artificially acquired active immunity

What is naturally acquired passive immunity?

Natural

Happens during pregnancy as antibodies move from the mother's bloodstream to the bloodstream of the fetus. Also transferred from mother's breast milk

Happens during pregnancy as antibodies move from the mother's bloodstream to the bloodstream of the fetus. Also transferred from mother's breast milk

naturally acquired passive immunity

What is artificially acquired passive immunity?

an immunization in recent outbreaks or emergency

situation

Immunization provides quick/ short lived protection to disease by the use of antibodies that can come from another person or animal

an immunization in recent outbreaks or emergency

situation

Immunization provides quick/ short lived protection to disease by the use of antibodies that can come from another person or animal

artificially acquired passive immunity

ADAPTIVE IMMUNE SYSTEM

Is adaptive immunity specific or non-specific?

specific

Adaptive immunity develops...

over time

TRUE or FALSE

In adaptive immunity, memory cells form to protect from future attacks

TRUE

TRUE or FALSE

The memory of the first encounter with an antigen (a toxin or a molecule on the surface of a pathogen that triggers an immune response) allows fora faster responses in subsequent exposures to that same antigen

TRUE

What's an antigen?

a toxin or a molecule on the surface of a pathogen that triggers an immune response

In adaptive immunity, the ----- is recognized as foreign, and the appropriate type of cell is selected to combat the pathogen with which it is associated

In adaptive immunity, the antigen is recognized as foreign, and the appropriate type of cell is selected to combat the pathogen with which it is associated

What type of cells are primarily in the adaptive immunity?

Lymphocytes

Depending on the type of lymphocyte, they respond to infection by ----- antibodies, ------ infected cells, or directly other immune responses

Depending on the type of lymphocyte, they respond to infection by producing antibodies, killing infected cells, or directly other immune responses

ADAPTIVE IMMUNE SYSTEM CELLS

What are the 2 main type of lymphocytes that are involved in adaptive immune responses?

T-lymphocytes (T cells)

B-lymphocytes (B cells)

Where do T cells mature?

Thymus

T cells are involved in ...

cell-mediated immunity

When does the initial activation of T cells occur?

The initial activation of T cells occurs when they encounter their specific antigen on the surface of an antigen-presenting cell (or APC)

What happens when T cells bind to antigen-presenting cells (APC)

They proliferate and differentiate into various types of T cells

What is the function of cytotoxic T cells?

Specialized to kill infected and abnormal cells

Some cytotoxic T cells produce Memory T cells

Specialized to kill infected and abnormal cells

Some cytotoxic T cells produce Memory T cells

cytotoxic T cells

Form killer T cells and help to cells in the future respond more quickly.

Respond to subsequent infections

memory T cells

What are memory T cells?

Form killer T cells and help to cells in the future respond more quickly.

Respond to subsequent infections

Function of T helper cells

Secrete cytokines that stimulate the division of T cells and B cells while alerting other types of WBCs

Secrete cytokines that stimulate the division of T cells and B cells while alerting other types of WBCs

T helper cells

Regulatory (suppressor) T cells

- inhibit T and B cells to stop the immune response

-release chemicals to suppress the activity of T cells

-stop the immune response to prevent uncontrolled activity

- inhibit T and B cells to stop the immune response

-release chemicals to suppress the activity of T cells

-stop the immune response to prevent uncontrolled activity

Regulatory (suppressor) T cells

Where do B cells mature?

Bone marrow

B cells are involves in humoral-mediated immunity or cell-mediated immunity?

humoral-mediated immunity

The initial activation of B cells occurs when

they encounter freely circulating antigens

Many B cells require co-stimulation by a ------- - -----

Helper T cell

After binding to specific antigens, B cells differentiate into ------ cells and ------ B cells

After binding to specific antigens, B cells differentiate into plasma cells and memory B cells

Function of plasma cells

secrete antibodies that bind to antigens

Function of memory B cells

Produce antibodies but only during subsequent infection

TISSUES

Function of bone marrow

Produces hematopoietic stem cells that give rise to all types of blood cells, including lymphocytes

Site of B cell maturation/ differentiation

Produces hematopoietic stem cells that give rise to all types of blood cells, including lymphocytes

Site of B cell maturation/ differentiation

Bone marrow

Function of Thymus

site of T cell maturation/differentiation

Function of Spleen

Splenic cord of the red pulp contain an abundance of macrophages and lymphocytes that help to filter aged red blood cells, pathogens, and debris from the blood

White pulp is a lymphatic tissue that consists almost entirely of B and T cells, and it provides a place for lymphocytes to proliferate

Splenic cord of the red pulp contain an abundance of macrophages and lymphocytes that help to filter aged red blood cells, pathogens, and debris from the blood

White pulp is a lymphatic tissue that consists almost entirely of B and T cells, and it provides a place for lymphocytes to proliferate/ multiply

Spleen

Function of lymph nodes

Provide a place for lymphocytes and other WBCs to proliferate/ multiply

(cortex contains B cells)

(macrophages/ medulla contains T cells)

Filter the lymph of microorganisms, toxins, and wastes

B cells produce antibodies that assist in the immune response

Provide a place for lymphocytes and other WBCs to proliferate/ multiply

(cortex contains B cells)

(macrophages/ medulla contains T cells)

Filter the lymph of microorganisms, toxins, and wastes

B cells produce antibodies that assist in the immune response

Lymph nodes

Function of MALT (Mucosa associated lymphoid tissue)

Small clusters of lymphatic cells that are found in the tonsils, appendix, and Peyer's patches of the small intestine

T cells, B cells, and macrophages provide protection against pathogens

Small clusters of lymphatic cells that are found in the tonsils, appendix, and Peyer's patches of the small intestine

T cells, B cells, and macrophages provide protection against pathogens

MALT (Mucosa associated lymphoid tissue)

LYMPHATIC SYSTEM

The lymphatic system consists of (7)

Thymus

Bone marrow

Tonsils

Spleen

lymphatic vessels

lymph nodes

lymph

What is lymph?

a colorless fluid containing white blood cells and fluid that leaks out of the blood capillaries

Where is lymph transported?

Transported in one direction (toward the neck) where it is emptied into the subclavian veins

Structure of lymphatic vessels

thin walls

valves to prevent backflow

Lymph is moved by contractions of

smooth and skeletal muscle

Lymphatic vessels are found everywhere in the body EXCEPT

the central nervous system and avascular tissues

What do lymph nodes contain?

lymphocytes

What do lymph nodes do?

filter out foreign substances

What are the 2 primary organs of the lymphatic system

Bone marrow

Thymus

The thymus and bone marrow...

produce mature lymphocytes

What are the secondary organs of the lymphatic system?

spleen

tonsils

The spleen and tonsils...

house lymphocytes

ANTIGEN/ ANTIBODY

What is an antigen?

a toxin or other foreign substance that induces an immune response in the body, especially the production of antibodies.

a toxin or other foreign substance that induces an immune response in the body, especially the production of antibodies.

antigen

Antigens are often...

large biomolecules

proteins

Where can antigens be found?

on the surface of antigenic substances such as viruses, bacteria, fungi, and pollen grains

What are foreign antigens?

antigens that originate outside the body

ex: viruses, bacteria, fungi, and pollen grains

What are self antigens?

Produced by the body and rarely initiate an immune response

Often trigger a response in other people like in the rejection of transplanted tissues or organs

What are antibodies?

Products of B cells that bind to specific antigens

Another word for antibodies

immunoglobulins

TRUE or FALSE

The binding of an antibody to an antigen can disarm the pathogen in a variety of ways

TRUE

Sometimes, the pathogens ---- before being destroyed

agglutinate

Antibodies can ---- the antigen by blocking its ability to attach to cells, or cause it to become insoluble and ---- out of solution

Antibodies can neutralize the antigen by blocking its ability to attach to cells, or cause it to become insoluble and precipitate out of solution

Antibodies can activate -----, a system of proteins that enhances the effectiveness of the immune response

complement

Other cells of the immune system can be called to action, and phagocytosis can be enhanced in a process called

opsonization

Antibodies can promote ---- to help slow the spread of infection

inflammation

EQUALIZATION OF FLUID DISTRIBUTION/ TRANSPORT OF PROTEIN AND LARGE GLYCERIDES