Lymph

Question 1

Central lymph organs

Answer 1

1. bone marrow- makes b-cells from stem cells.

2. Thymus- stem cells from bone marrow mature to T lymphocytes

Question 2

B-cells

1. made from __ in ___. Moves to?
2. interactions
3. functions.

Answer 2

1. made from stem cells in bone marrow–>blood–>
2. make plasma cells and memory b-cells from interaction with t-helper cells and macrophages.
3. Plasma cell= produces antibodies (b-cell that moved to lymph or tissue)
   Memory B-cell= secondary antibody response –recognizes antigens not on MHC complex (in bood)

Question 3

T cells

1. source
2. differentiation
3. types

Answer 3

1. stem cells from bone marrow
2. differentiate in thymus
3. T-helper and t-cytolytic

Question 4

T-helper cell

Answer 4

CD4+, interaction with b-cells and macrophages to stimulate response to antigen. recognizes MHC II on antigen presenting cells
Two types
1. Th1= viral and bacterial infections
2. Th2= parasitic infection

Question 5

T cytolytic

Answer 5

CD8+, recognize MHC I on antigen presenting cells

Question 6

Antigen presenting cells

1. Examples
2. function 1

Answer 6

1. EX: surveillance cells, macrophage lineage cells, kupffer cells, langerhans cells, dendritic cells, glial cells, fibroblasts, and mast cells.
2. phagocytose antigens, peptide from antigen binds MHC, MHC-antigen is presented to t-cells

Question 7

MHC types

Answer 7

major histocompatibility complex
1= on all nucleated cells
2= present on antigen presenting cells, endothelial cells, thymic epithelial reticular cells.

Question 8

Natural killer cell

1. made in ___ from ___.
2. part of ___immune system

Answer 8

1. from granular lymphocytes (= null cell) without CD or t-cell receptors (made in bone marrow?)
2. INNATE, also participates in adaptive immunity

Question 9

NK cell participation in innate immunity

Answer 9

recognize virus cells and cancer cells without needing antigen presenting cell to activate them

Question 10

NK cell participation in adaptive immunity

Answer 10

participate in antibody-dependent cell mediated toxicity. Recognizes an antibody on a pathogen infected cell and lyses the cell

Question 11

Peripheral lymph organs?

Answer 11

Spleen, lymph nodes, lymph nodules, tonsils, appendix, peyer’s patches (ileum)

Question 12

Subendothelial lymph tissue

Answer 12

= diffuse lymph tissue

1. diffuse lymphocytes present in subendothelium of intestinal, respiratory, and part of genitourinary system
2. lymph nodules (NOT ENCAPSULATED) in epithelium–can be solitary or aggregated
   - —>ex- peyer’s patches

Question 13

Lymph nodes–what are they?

Answer 13

dense lymphatic tissue surrounded by dense irregular connective tissue

Question 14

Lymph node capsule?

Answer 14

dense irregular CT that extends throughout the node. It branches into trabecula (where blood vessels branch) and comes together at the hilus of the node.

Question 15

Lymph Hilus

Answer 15

Lymph exits via efferent vessels.

Arteries and veins enter/leave the lymph at this.

Question 16

Stroma of lymph node?

Answer 16

capsule, trabeculae, reticular fiber network and cells

Question 17

Parts of a lymph node

Answer 17

Cortex - outer
Paracortex- intermediate
medulla-inner

Question 18

Lymph path

Answer 18

1. Subcapsular sinus- where afferent nodes empty (between cortex and capsule)
2. Trabecular sinus=intermediate sinus- run along trabecula
3. medullary sinuses-around medullary cords

Question 19

What is a lymphoid sinus?

Answer 19

it is the path that lymph takes after emptying from the afferent vessel.
the sinus is lined by squamous cells, reticular cells, and macrophages that are attached to the reticular fiber network.

Question 20

Reticular fiber network?

1. what is it?
2. function?

Answer 20

fixed macrophages
supports lining (simple squamous cells, reticular cells and macrophages) of lymphoid sinuses

Question 21

How do most lymphocytes enter the lymph node?

Answer 21

High endothelial venules. They are located in the paracortical zone. The selectins on lymphocyte membrane recognized the high endothelial venule and enter.

Question 22

High endothelial venule

1. what is it?
2. characteristics

Answer 22

1. entry route for lymphocytes into lymph node

2. lined by tall cuboidal epithelial cells

Question 23

Blood supply of lymph node

Answer 23

Enters and exits node at hilum.. capillary network around/inside lymphatic nodule.
Veins at base of nodule/paracortical area have “bulges” that allows lymphocytes to enter lymph node.

Question 24

Cells found in cortex of lymph node

Answer 24

large follicular dendritic cells= antigen presenting cells
T-cells- paranodular and inner cortex
B-cells-lymphoid nodule

Question 25

Lymphoid nodule

Answer 25

Found in the outer cortex of the node. Can be primary--no germinal center--- or secondary = germinal center.

Question 26

Germinal center Cells

Answer 26

Large lymphoblasts | marginal zone with lymphocytes and macrophages

Question 27

What is a germinal center--how does it come into existence?

Answer 27

B-cells in nodule are activated by helper t-cells to make lymphoblasts and eventually an antibody secreting plasma cell. this is a process of clonal expansion

Question 28

B-cell lymphoblasts 1. where are they 2. what activated them? 3. what are they becoming? 4. regulation?

Answer 28

1. in lymphoid nodule, now a germinal center 2. t-helper cell 3. antibody secreting plasma cell 4. YES--only b-cell lymphoblasts that have high affinity antibodies to the FDC antigen will become a plasma cell

Question 29

Where are the plasma cells located?

Answer 29

in the medullary cords

Question 30

What are other fates (other than the plasma cell) of the b-cell lymphoblasts?

Answer 30

1. they can have a low affinity antibody to the antigen presented to them by the FDC= apoptosis, macrophage food 2. b-cell lymphoblasts can have NO specificity for antigens. They accumulate in mantle zone of the lymphoid follicle

Question 31

Mantle zone

Answer 31

surrounds the lymphoid nodule germinal center. Contains b-cell lymphoblasts with

Question 32

Places with primarily 1. B-cells 2. t-cells

Answer 32

1. nodules and medullary cords= b-cells | 2. inner cortex regions=t-cells

Question 33

Cytokine signaling causes

Answer 33

segregation of cells within nodules

Question 34

Parts of medulla

Answer 34

medullary sinuses | medullary cord

Question 35

1. Peyer's patches are examples of? | 2. Cells and location?

Answer 35

1. Aggregated lymphoid nodules, found in ileum! | 2. B-cell in nodules; T-cells in paranodular area. Follicular epithelium has M-cells.

Question 36

Tonsils

Answer 36

3 "types" 1. Lingual 2. Pharygneal= adenoids 3. Palatine

Question 37

Lingual tonsils 1. location 2. what is it?

Answer 37

1. below posterior 1/3 of tongue | 2. diffuse infiltration of lymphocytes OR multiple nodules

Question 38

Pharyngeal Tonsils 1. location 2. characteristic?

Answer 38

1. Posterior wall of nasopharynx | 2. has ciliated pseudostratified columnar/stratified squamous (in old people)

Question 39

Palatine

Answer 39

1. between glossopalatine and pharyngeopalatine arches 2. base and sides enclosed in dense CT capsule 3. covered with stratified squamous epithelium with crypts that extend into parenchyma

Question 40

Crypts found in?

Answer 40

epithelium of palatine. they extend into the parenchyma

Question 41

Appendix has

Answer 41

diffusely scattered lymphoid elements and solitary nodules in LAMINA PROPRIA

Question 42

Lymphadenitis

Answer 42

Inflammation and swelling of lymph nodes due to immune reaction. Cells proliferate, also edema of node.

Question 43

Metastasis of cancer?

Answer 43

commonly happens in nodes

Question 44

Why are lymph nodes sources of lymphoma?

Answer 44

The cells frequently and rapidly divide and differentiate

Question 45

Graft rejection

Answer 45

PATIENTS immune system rejects graft and attacks it (t-cell mediated)

Question 46

Graft vs Host disease major and minor HC --H-Y HA-2

Answer 46

T-cells from GRAFT attack host. Big problem with bone marrow transplants. Can match Major HC and still have rejection of host (from graft) due to Minor HC Idk what this means, but learn it anyway -H-Y= male -HA-2=myosin