Lymphatic and Immune System: Functions, Cells, and Pathways

What is not a function of the lymphatic system?

Secretion of digestive enzymes

True or False: Lymphatic vessels constitute a one-way system that delivers interstitial fluid from the blood vessels to the extracellular space.

False

True or False: Lymph from the lower limbs drains into the right lymphatic duct.

False

True or False: Fat-containing lymph from the intestines drains into the cisterna chyli.

True

True or False: The thymus is the site of maturation of B cells.

False

True or False: Clusters of MALT located around the oral and nasal cavities are known as aggregated lymphoid nodules.

False

What lymphoid organ filters the blood?

Spleen

What lymphoid organ filters the lymph?

Lymph node

What is another name for nonspecific immunity?

Innate immunity

What is another name for specific immunity?

Acquired immunity

What makes up the body's first line of defense?

Surface barriers

True or False: Surface barriers contain substances in their secretion that kill pathogens and deter their growth.

True

True or False: Phagocytic cells of innate immunity include NK cells and basophils.

False

True or False: NK cells are cytotoxic cells that lyse and kill cancer cells and cells infected with certain viruses.

True

True or False: Interleukin-1 is a cytokine that prevents viral replication in infected cells.

False

Which functions are performed by complement proteins?

Cell lysis, opsonization, enhancing inflammation

What are the four cardinal signs of inflammation?

Edema, redness, pain, and heat

When naive B cells are activated, they differentiate into what?

Plasma cells and memory cells

What is IgD?

Antibody bound to the B cell plasma membrane

What is IgM?

Pentamer and potent agglutinating agent

What is IgG?

Most common antibody; crosses the placenta

What is IgA?

Antibody found in secretions

What is IgE?

Antibody involved in allergies and parasitic infections

True or False: In the primary immune response, the lag phase lasts about 5 days.

True

True or False: The secondary immune response is mediated by plasma cells.

False

What do subunit vaccines consist of?

Pathogens that are alive but unable to cause disease

How does active immunity differ from passive immunity?

Active immunity involves exposure to an antigen; passive immunity involves transfer of preformed antibodies.

On which type of cells are class I MHC molecules located?

All nucleated body cells

What do class I MHC molecules display?

Endogenous antigens

What is not a role of Th cells?

Stimulation of clonal selection

True or False: The cells involved in organ and transplant rejection are primarily B cells.

False

True or False: The immune response to a viral infection involves NK cells and different kinds of lymphocytes.

True

True or False: Neutrophils are critical components of the response to a parasitic infection.

False

What causes Type I hypersensitivity?

Release of inflammatory mediators from mast cells

What increases the risk of infection in a patient with AIDS due to HIV?

Destruction of Th cells

What conditions may lead to the development of autoimmunity?

Self antigens not previously encountered, foreign antigens mimicking self antigens, inappropriate display of class II MHC molecules, nonspecific activation of B cells

What part of the immune response is likely producing Eileen's flu-like symptoms?

Inflammation and fever as part of the innate immune response.

What does an elevated number of neutrophils indicate about the type of pathogen involved?

It suggests a bacterial infection.

What might elevated lymphocytes indicate?

A possible viral infection or other causes of systemic inflammation.

What type of hypersensitivity disorder might result from complement deficiencies?

A type III hypersensitivity disorder.

What are other consequences of complement deficiencies?

Impaired ability to lyse bacteria, enhance inflammation, neutralize viruses, and enhance phagocytosis.

How does blocking IgE function alleviate Terrence's asthma symptoms?

It prevents IgE from activating basophils and mast cells, reducing allergic responses.

What type of immunity is conferred by administering antivenin CroFab?

Passive immunity.

Will the antivenin CroFab confer lasting protection to your friend?

No, it will not confer lasting immunity.

What process likely caused Carla's axillary lymph nodes to swell?

Metastasis of cancer cells to the lymph nodes.

What complications might arise from the removal of Carla's lymph nodes?

Inhibition of interstitial fluid drainage, leading to edema.

Why might neutropenia lead to a bacterial infection in Mr. White?

Low neutrophil count impairs the body's ability to respond to bacterial pathogens.

Why is a bacterial infection particularly dangerous for Mr. White?

His neutrophil count is already low, preventing an adequate response to infection.

What components of the immune system are harmed by bone marrow destruction?

All types of leukocytes, as they are produced by the bone marrow.

What effect would bone marrow destruction have on hematocrit?

It would decrease hematocrit.

What symptoms might result from decreased hematocrit?

Fatigue, weakness, and pallor.

What effect does chemotherapy have on the skin's functions?

It thins the skin and makes it more prone to injury.

How does thinning skin affect immunity?

It reduces the skin's ability to function as the first line of defense.

How do lymphatic capillaries differ from blood capillaries?

Lymphatic capillaries are blind-ended and form a one-way system.

What is the main cell type located in lymphoid tissues and organs?

Reticular cells.

What is the consequence of removing the thymus in a newborn?

No T cell maturation, severely impacting immune function.

What is the role of reticular cells in lymphoid organs?

They produce reticular fibers and support the structure of lymphoid tissues.

What happens to the immune response if T cell maturation is halted?

There will be a severe impact on the ability of the immune system to function.

What is the site for T cell maturation?

Thymus

What is a key difference between innate and adaptive immunity?

Adaptive immunity has immunological memory.

What are the defense proteins of the immune system?

Complement system, phagocytes, antigens, mucus.

What is interstitial cystitis characterized by?

Erosion of the mucous membrane lining the urinary bladder.

What is compromised due to erosion of the mucous membrane?

First line of defense.

Which cytokines inhibit viral replication?

Interferons.

What condition is characterized by insufficient levels of neutrophils?

Neutropenia.

What is the main risk associated with neutropenia?

Greater risk of bacterial infection.

Which MHC molecules are recognized by naive helper T cells?

Class II MHC molecules.

What is the main function of Tc cells?

Kill abnormal infected cells.

What happens if a hypothetical poison alters self-antigens on kidney cells?

Tc cells will destroy the kidney cells.

When is a B cell considered sensitized?

When an antigen binds to its B cell receptor.

What type of immunity does tetanus antitoxin provide?

Passive immunity.

What type of immunity do tetanus antigens stimulate?

Active immunity.

How does the immune system scan for cancer cells?

Via immune surveillance.

How do some viruses evade the immune system?

By blocking or inhibiting cytokines such as interferons.

What is a consequence of a virus preventing Tc cell activation?

It will be harder to kill cells infected with the virus.

What type of cells does the HIV-1 virus infect?

Helper T cells.

What is an autoimmune disorder?

A disorder caused by the immune system reacting to self antigens.

Which type of hypersensitivity is affected by drugs that inhibit mast cell granule release?

Type I hypersensitivity.

Which of the following is not a cardinal sign of inflammation?

Fever.

What do inflammatory mediators cause?

Migration of phagocytes to the site of infection.

What is a direct result of arteriolar vasodilation?

Heat.

What is the production of antibodies?

The process by which the immune system creates proteins that neutralize pathogens.

What is phagocytosis?

The process by which cells engulf and digest pathogens.

What causes pain during inflammation?

Increased blood flow and the release of inflammatory mediators.

What role do interferons play in the immune response?

They recruit natural killer (NK) cells and inhibit viral replication.

Which cells can recognize reduced class I MHC molecules?

NK cells.

What components would an antiviral drug likely include?

Interferons.

What do helper T cell receptors recognize?

Class II MHC molecules.

What is the main function of activated helper T cells?

To secrete cytokines.

Which cells secrete antibodies?

Plasma cells.

What is the function of memory B cells?

To provide immunological memory.

What triggers B cell sensitization?

An antigen binding to the B cell receptor.

Which cells recognize class I MHC receptors?

Cytotoxic T cells.

Which antigen-presenting cells activate cytotoxic T cells?

Dendritic cells.

Which immune cells attack transplant grafts?

Cytotoxic T cells.

What is the primary function of the lymphatic system?

Returning excess interstitial fluid to the cardiovascular system.

What type of cells are primarily found in lymphoid follicles?

B cells.

Which organ filters pathogens from the blood?

Spleen.

What is the largest lymphatic duct in the body?

Thoracic duct.

Where do T cells mature?

Thymus.