Immunological System Anatomy 1

Question 1

Where is the thymus located?

Answer 1

In the upper anterior thorax just above the heart

Question 2

At what age is the thymus fully developed by?

Answer 2

By birth

Question 3

The involution of the thymus is almost complete by what age?

Answer 3

Thirty years of age. Thymus keeps growing through puberty then starts to atrophy and decrease in activity and size (this stage is called involution). This is caused by the increased sex hormones during puberty.

Question 4

True or false: The thymus receives lymph.

Answer 4

False, the only route of access by cells is via blood

Question 5

Describe the anatomy of the thymus

Answer 5

It is divided in the cortex which is filled with immature T cells and the medulla which is filled with mature T cells.

Question 6

What other cells inhabit the thymus?

Answer 6

Branched cortical and medullary epithelial cells, macrophages, and dendritic cells

Question 7

What role do macrophages in the thymus play?

Answer 7

Removal of thymocytes that fail to mature properly

Question 8

What role do epithelial reticular cells play in the thymus?

Answer 8

They test immature T cells for reactivity to “‘self’” proteins, and destroy any T cells that express auto-immunity tendencies

Question 9

What role do bone marrow stromal cells provide in B cell development?

Answer 9

They release different cytokines which trigger B cell development and attachment

Question 10

What part of the bone marrow do immature B cell inhabit?

Answer 10

The subendosteum

Question 11

What are the two central or primary lymphoid tissues?

Answer 11

Thymus gland and bone marrow. Primary lymphoid tissues are where progenitor cells differentiate into mature cells.

Question 12

What is extramedullary hemopoiesis

Answer 12

It the process by which the liver and spleen will attempt to produce blood cells if the bone marrow becomes too diseased

Question 13

What are peripheral or secondary lymphoid tissues?

Answer 13

Lymph nodes, lymph, gut-associated lymphoid tissue, and spleen. Secondary lymphoid tissues are where mature lymphocytes interact and generate immune responses.

Question 14

What cell is the most prominent within the lymphoid follicle of a lymph node?

Answer 14

B Cell. Versus T cells inhabit the thymus more.

Question 15

Where are T cells the most prominent within the lymph node?

Answer 15

Lymphoid paracotex

Question 16

Which portions of the tonsils does not have crypts?

Answer 16

Adenoids

Question 17

What is the purpose of tonsilar crypts?

Answer 17

They offer a complicated network of canals that increases surface area which allows immune cells a greater change of encountering microbes