5 Lymphoid Tissue

Question 1

T-F– plasma cells are included in b cell lymphocyte category?

Answer 1

True

Question 2

Are natural Killers a lymphocyte?

Answer 2

yes

Question 3

Why is it called B cells?

Answer 3

bursa fabricus in birds

Question 4

T-F–Thymus functions primarily in first 15 years of life.

Answer 4

True- maturation and selection of T cells

Question 5

Where is MALT found?

Answer 5

naso oropharynx
GI Tract
Lung- respiratory system

Urogenital

Question 6

T or F- Naive lymphocytes cells divide?

Answer 6

false- not dividing is what defines them

Question 7

Where are homing receptors for lymphocytes found?

Answer 7

high-walled endothelial venules

Question 8

T- F- lymphatic vessels also carry tissue fluid containing antigens from peripheral tissues to the lymph nodes?

Answer 8

True

Question 9

What does the hilum of the lymph nodes contain?

Answer 9

Enter- arteries and nerves

Exit- veins and efferents

Question 10

Besides t lymphocytes, what is found at the paracortex?

Answer 10

post-capillary venules that allow T lymphocytes to migrate into node.

Question 11

What do medulla cords contain?

Answer 11

B lymphocytes, plasma cells, macrophages

Question 12

What are lymph node sinus partially lined by?

Answer 12

reticular cells and macrophages

Question 13

B lymphocytes make up what percentage of circulating lymphocytes?

Answer 13

10-20%

Question 14

What is the earliest sign of B cell differentiation?

Answer 14

rearrangement of immunoglobulin heavy chain

Question 15

T or F- after rearrangement of the immunoglobulin heavy chain, there is rearrangement of both the lambda and kappa light chains at the same time?

Answer 15

False– only one rearranges at first. kappa or lambda

Question 16

Naive B cells express what Ig?

Answer 16

IgM and IgD

Question 17

What layers are found around the germinal follicle?

Answer 17

mantle and then marginal

Question 18

What makes up the dark zone of the germinal center?

Answer 18

proliferating centroblasts that form into centrocytes

Question 19

T or F- memory cells are also produced in the germinal center?

Answer 19

True

Question 20

What is a centroblast?

Answer 20

Activated B cell that is proliferating.

Question 21

What is an enlarged lymph node caused by benign or malignant conditions? difference in viral vs. bacterial?

Answer 21

Lymphadenopathy

• -follicular hyperplasia seen in bacterial infections
• -viral infections lead to parafollicular hyperplasia

Question 22

What is normally 150 grams, has thin fibrous capsule, cut surface red with gray specks, and stroma reticular connective tissue?

Answer 22

Spleen

Question 23

What is red pulp transversed by?

Answer 23

thin walled vascular sinuses separated by cords

Question 24

What type of circulations does the spleen have?

Answer 24

Open and closed

Question 25

Is the open component the fast component of spleen circulation?

Answer 25

No it is the slow component

Question 26

What splenic blood circulation is defined by capillary flow into splenic cords then filtered in sinusoids to reach veins?

Answer 26

Open circulation

Question 27

What splenic circulation pathway has direct passage from pencillary arteries to the sinus and then to trabecular veins?

Answer 27

Closed circulation---MOST OF THE CIRCULATION

Question 28

What does red pulp do?

Answer 28

REMOVAL OF UNWANTED ELEMENTS FROM THE BLOOD | -senescent red cells, damaged red or white cells, bacteria, cell debris

Question 29

What lymphoid cell region is located more near to the central arteriole in the spleen?

Answer 29

T cell region

Question 30

In the spleen, what are the layers of lymphoid tissue in order from central to eccentric?

Answer 30

T cell region B cell Region marginal sinus- surrounds B and T cell zones marginal zone- contains macrophage and lymphocytes

Question 31

What 2 things are commonly seen in asplenic people?

Answer 31

1 risk for bacterial infections | 2 have abnormal red cell inclusions- howell jolly bodies

Question 32

What pharyngeal pouches is thymus derived from?

Answer 32

3rd and 4th

Question 33

of thymus lobes?

Answer 33

2---then divided into lobules

Question 34

What types of cells are found in the thymus?

Answer 34

T lymphocytes Thymic epithelial cells Macrophages - for apoptotic thymocytes DEndritic cells

Question 35

What are whorls of epithelial cells seen in medullary region called?

Answer 35

Hassall's corpuscles

Question 36

Where does major proliferation happen of T cells in the thymus according to these lecture notes?

Answer 36

subcapsular space

Question 37

Where does interaction of MHC occur according to these notes in the thymus for reactivity testing?

Answer 37

deeper layer of cortex-thymic epithelial cells

Question 38

T cells are what percentage of circulating lymphocytes?

Answer 38

60-70%

Question 39

What syndrome causes absence of 3 and 4 pharyngeal pouches?

Answer 39

DiGeorges Syndrome

Question 40

Is Malt encapsulated as lymph nodes are?

Answer 40

No

Question 41

What major antibody is secreted by MALT system?

Answer 41

IgA