Lymphoid tissue Histology II (Capsulated)

Question 1

Classification of capsulated lymphoid tissues

Answer 1

Lobular and no-lobules

Question 2

Lobular

Answer 2

Thymus

Question 3

Non-lobular

Answer 3

spleen and lymph nodes

Question 4

thymus

Answer 4

produces only T-lymphocytes
decreases in size with age but continue to produce T-lymphocytes in adults

replaced by fat/connective tissue

Question 5

Thymus: structure

Answer 5

two lobes, connective tissue capsule, capsule septa which penetrates medulla

Question 6

thymic septa does what?

Answer 6

divides thymus into incomplete lobes

Question 7

Thymus staining pattern

Answer 7

dark cortex and light medulla

Question 8

Thymus “features”

Answer 8

no germinal centers but contains light staining medulla and dark staining cortex.

hassal’s corpuscles (in the medulla)

Question 9

Thymus cortex

Answer 9

site of T lymphocyte maturation

Question 10

Cells of the thymus cortex

Answer 10

1) subcapsular thymic epithelial cells
2) thymic cortical epithelial cells
3) maturing T-cells (developing thymocytes)
4) macrophages

Question 11

Cells in the thymic cortex

Answer 11

1. Subcapsular epithelial cells
2. cortical epithelial cells
3. macrophages
4. maturing lymphocytes

Question 12

Cells in the thymic medulla

Answer 12

1. medullary epithelial cells
2. thymus dendritic cells
3. macrophages
4. hassal’s corpuscles
5. mature lymphocytes

Question 13

Thymus blood barrier

Answer 13

only in cortex

Question 14

epithelial reticular cells

Answer 14

bound to capillaries, compose thymus blood barrier in cortex

Question 15

What does the TBB prevent?

Answer 15

most circulating antigens from reaching developing T cells