Ch 22 The Lymphatic System and Immunity

Give a function for each of the following: (a) cytotoxic T cells, (b) helper T cells, (c) suppressor T cells, (d) plasma cells, (e) NK cells, (f) stromal cells, (g) thymic epithelial cells, (h) interferons, (i) pyrogens, (j) T cells, (k) B cells, (l) interleukins, (m) tumor necrosis factor, (n) colony-stimulating factors

(A) Cytotoxic T cells: lymphocytes responsible for cell-mediated immunity; (B) Helper T cells: stimulate the activation and function of T cells and B cells; (C) Suppressor T cells: inhibit the activation and function of both T cells and B cells; (D) Plasma cells: produce and secrete antibodies; (E) NK cells: recognize and destroy abnormal cells; (F) Stromal cells: produce interleukin-7, which promotes the differentiation of B cells; (G) Thymic epithelial cells: regulate T cell development and function; (H) Interferons: interfere with viral replication inside the cell and stimulate the activities of macrophages and NK cells; (I) Pyrogens: reset the body's thermostat, causing a rise in body temperature (fever); (J) T cells: provide cell-mediated immunity, which defends against abnormal cells and pathogens inside cells; (K) B cells: provide humoral immunity, which defends against antigens and pathogens in the body (but not inside cells); (L) Interleukins: enhance innate (nonspecific) defenses and increase T cell sensitivity and stimulate B cell activity; (M) Tumor necrosis factor: slow tumor growth and kill sensitive tumor cells; (N) Colony-stimulating factors: stimulate the production of blood cells in the bone marrow and lymphocytes in lymphoid tissues and organs

Phagocytes move through capillary walls by squeezing between adjacent endothelial cells, a process known as (a) diapedesis, (b) chemotaxis, (c) adhesion, (d) perforation

(A) Diapedesis

Skin tests are used to determine if a person (a) has an active infection, (b) has been exposed to a particular antigen, (c) carries a particular antigen, (d) has measles, (e) can produce antibodies

(B) Has been exposed to a particular antigen

A decrease in which population of lymphocytes would impair all aspects of an immune response? (a) cytotoxic T cells, (b) helper T cells, (c) suppressor T cells, (d) B cells, (e) plasma cells

(B) Helper T cells

Lymph from the right arm, the right half of the head, and the right chest is received by the (a) cisterna chyli, (b) right lymphatic duct, (c) right thoracic duct, (d) aorta

(B) Right lymphatic duct

Blocking the antigen receptors on the surface of lymphocytes would interfere with (a) phagocytosis of the antigen, (b) that lymphocyte's ability to produce antibodies, (c) antigen recognition, (d) the ability of the lymphocyte to present antigen, (e) opsonization of the antigen

(C) Antigen recognition

CD4 markers are associated with (a) cytotoxic T cells, (b) suppressor T cells, (c) helper T cells, (d) a, b, and c

(C) Helper T cells

The major histocompatibility complex (MHC) (a) is responsible for forming lymphocytes, (b) produces antibodies in lymph glands, (c) is a group of genes that codes for human leukocyte antigens, (d) is a membrane protein that can recognize foreign antigens, (e) is the antigen found on bacteria that stimulates an immune response

(C) Is a group of genes that codes for human leukocyte antigens

Perforins are proteins associated with the activity of (a) T cells, (b) B cells, (c) NK cells, (d) plasma cells

(C) NK cells

Compared with innate defenses, adaptive defenses (a) do not distinguish between one threat an another, (b) are always present at birth, (c) protect against threats on an individual basis, (d) deny the entry of pathogens to the body

(C) Protect against threats on an individual basis

Red blood cells that are damaged or defective are removed from the bloodstream by the (a) thymus, (b) lymph nodes, (c) spleen, (d) tonsils

(C) Spleen

The specificity of an antibody is determined by the (a) fixed segment, (b) antigenic determinants, (c) variable region, (d) size of the antibody, (e) antibody class

(C) Variable region

The most beneficial effect of fever is that it (a) inhibits the spread of some bacteria and viruses, (b) increases the metabolic rate by up to 10%, (c) stimulates the release of pyrogens, (d) achieves a and b

(D) Achieves a and b

Complement activation (a) stimulates inflammation, (b) attracts phagocytes, (c) enhances phagocytosis, (d) achieves a, b, and c

(D) Achieves a, b, and c

Anatomically, lymphatic vessels resemble (a) elastic arteries, (b) muscular arteries, (c) arterioles, (d) medium veins, (e) the venae cavae

(D) Medium veins

Compare and contrast the effects of complement with those of interferon

Complement can rupture the target cell's plasma membrane by releasing perforin, kill the target cell by secreting a cytotoxic lymphotoxin, or activate genes within the nucleus of the cell that stimulate programmed cell death (apoptosis). Interferon interferes with viral replication inside virus-infected cells by triggering the production of antiviral proteins

What are the three classes of lymphocytes, and where does each class originate?

T cells, derived from the thymus; B cells, derived from red bone marrow; and NK cells, derived from red bone marrow

An anesthesia technician is advised that she should be vaccinated against hepatitis B, which is caused by a virus. She is given one injection and is told to come back for a second injection in a month and third injection after six months. Why is this series of injections necessary?

The injections are timed to trigger the primary and secondary responses of the immune system. Upon first exposure to hepatitis antigens, B cells produce daughter cells that differentiate into plasma cells and memory B cells. The plasma cells begin producing antibodies, which represent the primary response to exposure. However, the primary response does not maintain elevated antibody levels for long periods, so the second and third injections are necessary to trigger secondary responses, when memory B cells differentiate into plasma cells and produce antibody concentrations that remain high much longer

How does a cytotoxic T cell destroy another cells displaying antigens bound to Class I MHC proteins?

Cytotoxic T cells kill by rupturing the target cells' plasma membrane, by stimulating lymphotoxin secretion, or by activating genes in the nucleus that program cell death

How does the formation of an antigen-antibody complex cause the elimination of an antigen?

Formation of an antigen-antibody complex eliminates antigens by neutralization; by agglutination and precipitation; by activating complement; by attracting phagocytes; by opsonization; by stimulating inflammation; or by preventing bacterial and viral adhesion

What seven defenses, present at birth, provide the body with the defensive capability known as innate (nonspecific) resistance?

Innate (nonspecific) defenses: physical barriers; phagocytic cells; immune surveillance; interferons; complement system; inflammation; and fever

Give one example of each type of immunity: innate immunity, naturally acquired active immunity, artificially induced active immunity, artificially induced passive immunity, and naturally acquired passive immunity

Innate immunity is genetically programmed; an example is immunity to fish diseases. Naturally acquired immunity develops after birth from contact with pathogens; an example is exposure to chickenpox in grade school. Artificially induced active immunity develops intentional exposure to a pathogen; an example is administration of measles vaccine. Artificially induced passive immunity is temporary immunity provided by injection with antibodies produced in another organism, such as antibodies against rabies. Naturally passive immunity is gained by acquiring antibodies from mother's milk or placental exchange

List the specific functions of each of the body's primary and secondary lymphoid tissues and organs

Red bone marrow: maintains normal lymphocyte populations and other defense cells, such as monocytes and macrophages; thymus: production of mature T cells and hormones that promote immune functions; spleen: filtration of blood, recycling of red blood cells, detection of blood-borne pathogens or toxins; lymph node: filtration of lymph, detection of pathogens, initiation of immune response; lymphoid nodules, and MALT: defense of entrance and passageways of digestive tract and protection of epithelial lining of respiratory, urinary, and reproductive tracts against pathogens and foreign proteins or toxins; lymphatics: movement of lymph from interstitial spaces to the venous system