Primary lymphoid tissues: bone marrow

Question 1

What are primary lymphoid tissues?

Answer 1

Tissues where lymphocytes develop and mature to a stage where they are able to recognise antigen.

Question 2

What are primary lymphoid tissues also known as?

Answer 2

Central lymphoid organs

Question 3

What are all immune cells derived from? What else is derived from this?

Answer 3

Haematopoeitic stem cells in the bone marrow.

Its also the site of origin of red blood cells and platelets.

Question 4

What are the two types of marrow?

Answer 4

red and yellow

Question 5

What are the two types of bone marrow involved with?

Answer 5

Red marrow is involved in haematopoiesis. Yellow marrow is made of adipocytes (fat cells).

Question 6

What do lymphocytes descend from?

Answer 6

A common lymphoid progenitor.

Question 7

Where do B cells mature?

Answer 7

They mature entirely in the bone marrow and enter the blood, most die within a few days as they fail to meet their antigen.

Question 8

What is the T cell life cycle like?

Answer 8

T- cells leave the bone marrow as immature progenitors and travel to the thymus, via the blood, to complete maturation and undergo selection.