Lymph Histo- Nbde I

Front 1

What are the capsule-enclosed organs of the lymphoid system?

Back 1

1. Lymph nodes
2. Thymus
3. Spleen

Front 2

What is the 1st line of defense against infection?

Back 2

Epithelium

Front 3

2nd & 3rd lines of defense against infection are?

Back 3

Innate immune system
Adaptive immune system

Front 4

What are the components of innate immune system?

Back 4

1. Cytokines
2. Macrophages
3. Neutrophils
4. NK cells

Front 5

What are cytokines?

Back 5

Signaling molecules released by immune cells

Front 6

Which cytokines have antiviral properties?

Back 6

Interferons

Front 7

Which cytokines are chemoattractants?

Back 7

Chemokines

Front 8

Which cytokines stimulate differentiation & mitotic activity of hemopoietic cells?

Back 8

Colony-stimulating factors

Front 9

What cell types are present in adaptive immune system?

Back 9

1. T cells
2. B cells
3. Antigen presenting cells

Front 10

Recognition of foreign Ag can trigger which 2 responses in adaptive immune system?

Back 10

1. Humoral immune response (Ab)
2. Cell-mediated immune response (cytotoxic cells)

Front 11

B cells are produced where & become immunocompetent where?

Back 11

B-CELLS;
-Produced: bone marrow
-Immunocompetent: Bone Marrow

Front 12

T cells are produced where & become immunocompetent where?

Back 12

T-CELLS:
-Produced: Bone Marrow
-Immunocompetent: Thymus

Front 13

What are the 4 distinct properties of the adaptive immune system?

Back 13

1. Specificity
2. Diversity
3. Memory
4. Self/non-self recognition

Front 14

Primary (central) lymphoid organs include? (3)

Back 14

1. Fetal liver
2. Pre- & post-natal bone marrow
3. Thymus

Front 15

Function of primary (central) lymphoid organs?

Back 15

Responsible for development & maturation of lymphocytes- bone marrow & thymus

Front 16

Secondary (peripheral) lymphoid organs include? (4)

Back 16

1. Lymph nodes
2. Spleen
3. Mucosa-associated lymphoid tissue (MALT)
4. Post-natal bone marrow

Front 17

Function of secondary (peripheral) lymphoid organs?

Back 17

Provide environment where immunocompetent cells can react w/ each other & w/ Ag & other cells

Front 18

Thymus arises from which pharyngeal pouches?

Back 18

3rd (maybe 4th)

Front 19

Capsule of the thymus is composed of?

Back 19

Dense irregular collagenous CT

Front 20

What types of cells are present in the cortex of the thymus? (3)

Back 20

1. T lymphocytes
2. Macrophages
3. Epithelial reticular cells

Front 21

Epithelial reticular cells of thymus cortex are thought to derive from?

Back 21

Endoderm of pouch 3

Front 22

Function of Type I Epithelial Reticular Cells?

Back 22

Separate capsule & septa from vascular elements via occluding junctions-- "Blood-Thymus Barrier"

Front 23

Function of Type II Epithelial Reticular cells of thymus?

Back 23

Mid-cortex
-Long processes that connect w/ desmosomes
-Subdivide cortex into smaller compartments

Front 24

Function of Type III Epithelial Reticular cells of thymus?

Back 24

Located in deep cortex & corticomedullary junction-- Form occluding junctions that isolate cortex from medulla

Front 25

T cells in cortex are completely isolated from foreign antigens due to?

Back 25

Occluding junctions of epithelial reticular cells

Front 26

Which cell types are more abundant in the medulla of the thymus?

Back 26

More epithelial reticular cells (Type IV, V, VI)

Front 27

Arteries that supply thymus are branches from which 2 arteries?

Back 27

1. Internal thoracic artery
2. Thyroid artery

Front 28

Cortical capillaries of thymus are surrounded by what cells?

Back 28

Type I epithelial reticular cells --> Forms Thymus-Blood Barrier

Front 29

Which hormones are released from thymus & involved in T cell maturation?

Back 29

1. Thymosin
2. Thymopoeitin
3. Thymulin
4. Thymic Humoral factor

Front 30

What effect do adenocorticosteriods have on T cell maturation?

Back 30

DECREASE T cell numbers in thymic cortex

Front 31

What effect does thyroxin have on thymus?

Back 31

Stimulates cortical epithelial reticular cells to increase thymulin production

Front 32

What effect does somatotropin have on thymus?

Back 32

Promotes T cell development in cortex

Front 33

Where is the hilum of the lymph node located?

Back 33

Concave side

Front 34

What is found at the hilum of the lymph node?

Back 34

Efferent lymph vessels
Blood vessels

Front 35

Lymph node parenchyma contains?

Back 35

1. B cells
2. T cells
3. Antigen-presenting cells
4. Macrophages

Front 36

What are the 3 regions of a lymph node?

Back 36

1. Cortex
2. Paracortex
3. Medulla

Front 37

Afferent lymphatics of lymph node empty into?

Back 37

Subcapsular sinus

Front 38

What forms the framework of the lymph node?

Back 38

Network of reticular suspended from capsule & trabeculae

Front 39

Subcapsular sinus is continous w/?

Back 39

Cortical (paratrabecular) sinuses

Front 40

Cortical (paratrabecular) sinuses drain lymph to?

Back 40

Medullary sinuses

Front 41

Lymph in medullary sinuses exits via?

Back 41

Efferent lymph vessels

Front 42

Sinuses contain a network of which type of cells?

Back 42

Stellate reticular cells

Front 43

How do lymphod cells enter or leave sinuses?

Back 43

Passing by endothelial cells

Front 44

Primary lymphoid nodules are spherical aggregations of?

Back 44

B lymphocytes-- virgin & memory cells

Front 45

Germinal centers are found in?

Back 45

Secondary lymphoid nodules

Front 46

Germinal centers are though to be?

Back 46

Site of memory B cell & plasma cell proliferation

Front 47

Paracortex of lymph nodes contains mostly?

Back 47

T cells
(Thymus-dependent zone)

Front 48

What activates T cells in paracortex of lymph nodes?

Back 48

Antigen-presenting cells from other parts of body migrate to paracortex to activate T-cells

Front 49

Where are there high endothelial venules located in paracortex of lymph nodes?

Back 49

Bring lymphocytes into lymph nodes
B cells migrate --> Cortex
T cells migrate --> Paracortex

Front 50

What is found within the medulla of lymph nodes?

Back 50

-Lymphocytes
-Plasma cells
-Macrophages
-Network of reticular fibers & reticular cells

Front 51

What is the purpose of the sinus system in lymph nodes?

Back 51

Slows lymph flow --> allowing more time for resident macrophages to destroy foreign particulate matter (99% impurities removed)

Front 52

What is the largest lymphoid organ in the body?

Back 52

Spleen

Front 53

What type of CT is the capsule of the spleen?

Back 53

Dense irregular fibroelastic capsule