Organs and Cells

Question 1

Network of cells, tissues, and organs designed to protect from pathogens, eliminate altered self-cells, fight tumors, and maintain homeostasis.

Answer 1

Immune system

Question 2

What are the types of pathogens the immune system defends against, based on their location?

Answer 2

Intracellular
Extracellular

Question 3

Examples of intracellular pathogens

Answer 3

viruses, some bacteria/parasites

Question 4

Examples of extracellular pathogens

Answer 4

most bacteria, fungi, parasites

Question 5

Organs that regulate the maturation of lymphocytes

Answer 5

Primary Lymphoid Organs

Question 6

Primary lymphoid organs (4)

Answer 6

• Thymus
• Bursa of Fabricius (birds)
• Bone marrow
• Peyer’s patches (some spp.)

Question 7

Organ where immature T cells mature into immunocompetent T cells located in thoracic cavity, extending into the neck in some species (e.g., cattle, pigs)

Answer 7

Thymus

Question 8

Zinc dependent

Answer 8

Thymulin

Question 9

What happens to T cells in the thymus that strongly bind to self-antigens or don’t bind at all?

Answer 9

Apoptosis (negative selection)

Question 10

What are CD4 and CD8 markers—surface proteins used in T cell differentiation—used to recognize?

Answer 10

CD4 binds MHC II; CD8 binds MHC I (positive selection required)

Question 11

Bird-specific organ for maturation and differentiation of B cells

Answer 11

Bursa of Fabricius

Question 12

Dense lymphoid structures in the ileum—important in mammals for B cell proliferation and antigen transport via M cells

Answer 12

Peyer’s patches

Question 13

Hematopoietic organ and B cell maturation site also responsible for producing blood cells and acting like the bursa (birds) or Peyer’s patches (pigs)

Answer 13

Bone marrow

Question 14

What are secondary lymphoid organs—sites of lymphocyte interaction with antigens and immune response activation? (4)

Answer 14

• lymph nodes
• spleen
• tonsils
• bone marrow (adults)

Question 15

Bean-shaped filters on lymphatic vessels

Answer 15

Lymph nodes

Question 16

Structures of Lymph nodes (3)

Answer 16

• Cortex (B cells)
• Paracortex (T cells)
• Medulla (mixed immune cells)

Question 17

Blood-filtering lymphoid organ

Answer 17

Spleen

Question 18

Spleen is divided into? (2)

Answer 18

Red pulp
White pulp

Question 19

Part of spleen that stores RBCs and traps antigens

Answer 19

Red pulp

Question 20

Part of spleen responsible for immune responses

Answer 20

White pulp

Question 21

Pluripotent cells from bone marrow—capable of self-renewal and differentiation into lymphoid and myeloid progenitors

Answer 21

Hematopoietic stem cells

Question 22

What cells originate from the myeloid lineage—bone marrow–derived immune cells? (7)

Answer 22

• neutrophils
• eosinophils
• basophils
• monocytes
• mast cells
• platelets
• RBCs

Question 23

First line of defense of the immune system known for rapid migration to infection, phagocytosis, and respiratory burst

Answer 23

Neutrophils

Question 24

Monocyte-derived long-lived cells responsible for phagocytosis, antigen presentation, and cytokine production (e.g., IL-1, TNF-α)

Answer 24

Macrophages

Question 25

Motile IgE-associated granulocytes mainly active against helminths and allergens

Answer 25

Eosinophils

Question 26

Non-phagocytic granulocytes with IgE receptors filled with histamine and other mediators of immediate hypersensitivity

Answer 26

Basophils

Question 27

Lymphoid Lineage? (3)

Answer 27

B cells T cells Natural Killer (NK) cells

Question 28

What are helper T cells (CD4)—cells that activate other immune cells—activated by?

Answer 28

Antigens presented with MHC II molecules

Question 29

subsets of CD4+ T cells

Answer 29

Th1 and Th2 cells

Question 30

Th1 respond to what?

Answer 30

viruses/bacteria

Question 31

Th2 respond to what?

Answer 31

parasites

Question 32

Kill other cells that are perceived as foreign or abnormal

Answer 32

Effector or Cytotoxic T cells (CD8)

Question 33

What are cytotoxic T cells (CD8)—cells that kill abnormal cells—activated by?

Answer 33

Antigens presented with MHC I molecules

Question 34

Cells that suppress immune responses important for preventing overreaction after infection is cleared

Answer 34

Regulatory T cells (CD8)

Question 35

CD8+ T cells involved in tissue rejection also essential for fighting cancer and mediating allergic responses

Answer 35

Hypersensitivity T cells

Question 36

T cell receptor made of 6 glycoproteins—responsible for recognizing antigens presented on infected or antigen-presenting cells

Answer 36

TCR

Question 37

What are B cells—antibody-producing lymphocytes—capable of becoming?

Answer 37

Plasma cells or Memory B cells

Question 38

Antibody factories

Answer 38

Plasma cells

Question 39

What are BCRs—antigen receptors on B cells—secreted as when in soluble form?

Answer 39

Antibodies (Immunoglobulins)

Question 40

What are Natural Killer cells—large non-phagocytic lymphocytes—best at killing?

Answer 40

Tumor and virus-infected cells without prior sensitization

Question 41

Antigen-presenting cells with dendritic processes—derived from bone marrow

Answer 41

Dendritic cells

Question 42

APCs found in T cell zones of lymphoid organs—best at presenting antigen to CD4+ T helper cells

Answer 42

Integrating dendritic cells

Question 43

Cells found in germinal centers—important for displaying antigens to B cells via immune complexes

Answer 43

Follicular dendritic cells

Question 44

Found in epidermis and mucous membrane

Answer 44

Langerhans cells

Question 45

Arise late in fetal life and persist in adults

Answer 45

Secondary Lymphoid Organs

Question 46

Destruction of ingested bacterium occurs through generation of what?

Answer 46

Potent oxidants

Question 47

Potent oxidants cause what?

Answer 47

Respiratory burst