A & P II Ch 4: Lymphatic System

Filters blood, removing old red blood cells and pathogens, and plays a role in immune response

Spleen

Site of T-lymphocyte maturation and differentiation

Thymus

Produces red blood cells, platelets, and white blood cells; acts as the primary site of hematopoiesis in adults

Red bone marrow

Filters lymph, trapping bacteria and other microorganisms that can cause disease.

Lymph nodes

Contains high concentrations of lymphoid tissue; thought to play a role in immune response to ingested substances

Peyer’s patches

Play a role in immune system by protecting the entrance of the pharynx, the body's air and food path

Tonsils

Plays a role in immune response and has been suggested to store good bacteria, helping in the re-inoculation of the gut

Appendix

What is lymph?

Excess interstitial fluid that needs to be returned to the vasculature.

What constitutes the first line of defense in the innate immune system against pathogen entry into the body?

Physical and chemical barriers such as the skin and mucous membranes

Which of the following cells of the innate immune system is primarily responsible for directly killing infected cells or cells that have turned cancerous?

Natural killer cells

_______ cause vasodilation by relaxing vascular smooth  muscle and are a major cause of the pain associated with inflammation.

Prostaglandins

What is the main difference between interferons and interleukins?

Interferons help regulate the immune response to viruses, while interleukins are involved in activating the body’s immune response.

The splitting apart of the C3 protein causes what to occur? 

C3a diffuses away to increase inflammatory response. 

C3b binds to the cell to activate the MAC.

Which statement accurately describes the relationship among antigens,  antibodies, and antigenic determinants (epitopes)?

Antigens are molecules found on the surface of pathogens that are recognized by the immune system, antibodies are proteins produced by immune cells to recognize pathogens, and antigenic determinants (epitopes) are specific parts of the antigen molecule that antibodies bind to. 

A cell is infected with a virus. The immune system needs to identify and destroy the infected cell. Which molecule is primarily responsible for presenting viral pieces on the cell surface to alert the immune system?

MHC I complex, which presents viral antigens to T cells,  signaling that the cell is infected and needs to be destroyed.

True or False: Antibody-mediated immunity is the function of T cells. 

False, antibody-mediated immunity is the function of B cells.

Which of the following cells are not antigen-presenting cells?

T cells

Which type of cell will have class II MHC proteins?

Macrophages

True or false: Self-tolerance is the lack of immune cell reactivity to peptide fragments expressed from one's own genes.

True

A substance that can be recognized and bound by an antibody is called what?

Antigen

What are haptens?

Small molecules that become immunogenic when attached to a larger complex.

What is an epitope?

A small region within an antigen that an antibody can bind to.

How does the immune system typically respond to self-antigens?

It recognizes them as "safe" and does not mount an immune response

Which cells present antigens on Class I MHC proteins?

All nucleated cells in the body

True or false: Antigenic determinants on a carbohydrate antigen are more diverse than those on a protein antigen.

False, Antigenic determinants on a carbohydrate antigen are less diverse than those on a protein antigen.

True or false: Antigen specificity refers to the ability of an antibody to recognize and bind to any foreign antigen.

False, Antigen specificity refers to the ability of an antibody to recognize and bind to a specific foreign antigen and not any antigen in general.

T cells mature and become immunocompetent in which organ or tissue?

Thymus

_____________________  is the destruction of B cells that recognize self-antigens in the bone marrow.

Central tolerance

This antibody is most associated with allergic reactions:

IgE

Which statement accurately describes an antigen-antibody immune function?

Complement system activation by the antigen-antibody complex leads to  a cascade of events that enhances phagocytosis and can directly lyse pathogens. 

Antibodies are secreted by __________.

Plasma cells

Which regulator triggers B and T cells to multiply when there is an antigen identified?

Cytokines

What leads to the destruction or inactivation of B cells during central tolerance?

Binding strongly to self-antigens

Nirsevimab is a monoclonal antibody vaccination given to infants and adults over 60 years old to protect against RSV (respiratory syncytial virus). What is the best way to classify the immunity provided by the vaccine?

Passive; artificially acquired

What occurs if a B cell receives no signals from a helper T cell?

It is signaled to undergo apoptosis

Where do plasma cells often migrate back to after their activation?

Bone marrow

What is the immediate result of clonal expansion in B cells?

Secretion of antibodies with antigenic specificity

Which type of antibody is transferred from mother to fetus?

IgG

Binding soluble antigens to making them insoluble, triggering phagocytosis

Precipitation

Binding pathogens and clumping them together for phagocytosis

Agglutination

Provides attachment for C1, triggering a cascade leading to C3B activation

Complement activation

Coating pathogen so it cannot bind to its receptor.

Neutralization

True or False: In the process of positive selection, T cells must not recognize self antigens.

False: In the process of negative selection, T cells must not recognize self-antigens.

CD4 markers on T cells respond to antigens on:

Class II MHC

These cells regulate the activity of B cells by triggering differentiation into plasma cells.

Th2

Why does MHC polymorphism make organ transplantation difficult?

It increases the likelihood of the recipient's immune system recognizing the transplanted organ as foreign and rejecting it

Regulatory T cells __________.

Decrease T cell activity and suppress antibody activation

What do thymocytes develop into?

Functional T cells

What is T cell tolerance?

The process of eliminating T cells that might attack the body's own cells

What happens to thymocytes that cannot bind to MHC molecules?

They are eliminated

True or false: Negative selection is when T cells must recognize self major histocompatibility proteins (self-MHC).

False; Positive selection is when T cells must recognize self major histocompatibility proteins (self-MHC). OR Negative selection is when T cells must not recognize self-antigens.

Which of the following statements best describes clonal expansion.

It refers to the rapid division of T cells after activation.

True or false: The term "polyclonal response" refers to the stimulation of multiple types of T cell clones.

True

CD4 markers respond to antigens on which MHC proteins?

Class II MHC proteins

Which of the following is NOT a function of helper T cells?

Killing infected cells directly

True or false: Graft-versus-host disease is associated with kidney transplants.

False; Graft-versus-host disease is associated with bone marrow transplants.

True or false: Positive selection in the thymus eliminates thymocytes that bind MHC molecules.

False; Positive selection in the thymus eliminates thymocytes that cannot bind to MHC molecules.

True or false: T cell receptors recognize antigens based on their amino acid sequence.

True

This is an inherited immunodeficiency disease that affects multiple genes, impacting both T cells and B cell responses in the body.

SCID

Which of the following best describes a Type I hypersensitivity reaction?

It is an immediate reaction caused by IgE antibodies binding to allergens, leading to histamine release from mast cells.

Which of the following statements accurately describes a common characteristic shared by Rheumatoid Arthritis (RA), Type I Diabetes, and Lupus?

They are autoimmune diseases where the body's immune system mistakenly attacks its own tissues.

A rapid drop in blood pressure and bronchial constriction are characteristic of which type of hypersensitivity?

Type 1

Which of the following is a potential effect of inherited immunodeficiencies?

Increased susceptibility to some Gram-negative bacteria

What is severe combined immunodeficiency disease (SCID) characterized by?

Both B cell and T cell adaptive immune response affected

How is HIV primarily transmitted?

Through semen, vaginal fluids, and blood

Which of the following cell types does HIV use to enter cells?

CD4 cells

In Type I hypersensitivity, what is the specificity of the response predicated on?

The binding of allergen-specific IgE to the mast cell surface

A tuberculin test triggers which type of hypersensitivity? What does a positive tuberculin test indicate?

Type IV

True or false: HIV targets CD4 helper T cells, which are crucial for both T cell immune responses and antibody responses.

True

True or false: Immediate hypersensitivity is mediated by T cells and delayed hypersensitivity by IgE antibodies.

False; Immediate hypersensitivity is mediated by IgE antibodies and delayed hypersensitivity by T cells.

True or false: Rheumatoid arthritis is an autoimmune disorder where the immune system attacks the joints and can lead to joint deformity.

True

The thoracic duct empties lymph into the _________.

Left subclavian vein

Where is the spleen located

On the left side of the body between the stomach and diaphragm

Which of the following is not a similarity between lymphatic capillaries and blood capillaries?

Both are blind-sided (closed on one end) to allow for one-way flow.

The lumbar and intestinal trunks drain into the ___________.

Cisterna chyli

Place the following in order from flow starting at the tissues to return to the cardiovascular system:

1. Lymphatic capillary

2. Collecting vessels

3. Lymphatic trunks

4. Lymphatic ducts

Lymphoid tissue is associated with ______ tissue.

reticular connective tissue

This lymphoid organ is known as the "RBC graveyard" because old, worn out RBC are destroyed here.

Spleen

Bed-ridden patients who are not mobile are at risk for developing edema (swelling) because:

Less skeletal muscle contraction reduces the movement of lymph in the lymphatic vessels and it accumulates in the interstitial space.

Germinal centers of lymphoid follicles typically contain _________.

B cells

Which tonsil is found at the base of the tongue?

Lingual

What role do CD4+ cells play in the immune system that is significantly impaired by HIV infection?

They serve as key orchestrators in the immune response, helping activate both B cells and cytotoxic T cells

Cytotoxic T cells are identified by which surface protein marker?

CD8

How does HIV primarily affect the immune system, leading to immunodeficiency?

By infecting and reducing the function of helper T cells (CD4+ cells)

Why are patients with advanced HIV or AIDS more susceptible to opportunistic infections like Pneumocystis jirovecii pneumonia?

Decreased number of helper T cells compromises the function of the adaptive immune response

What is a key factor leading to the progression of HIV to AIDS?

Continuous decline in the number of helper T cells (CD4+ cells)

Which of the following best describes the mechanism by which HIV enters and replicates within a host cell?

HIV attaches to the CD4 receptor and a coreceptor on the helper T cell, allowing entry and reverse transcription of its RNA

What role do CD4+ cells play in the immune system that is significantly impaired by HIV infection?

They serve as key orchestrators in the immune response, helping activate both B cells and cytotoxic T cells

Which MHC class do helper T cells primarily interact with?

MHC class II

Which of the following is true about primary vs secondary immunodeficiency?

Primary is always congenital, while secondary is always acquired

Severe combined immunodeficiency (SCID) is a _______ immunodeficiency, whereas acquired immunodeficiency syndrome (AIDS) is a ________ immunodeficiency. 

Primary; secondary