q29 - raji_321

[ArchivalUser]

During embryological development, hematopoiesis occurs in different organs at different times. Which of the following are the correct organs, in the correct sequence, at which hematopoiesis occurs embryologically?
A. Amnion, yolk sac, placenta, bone marrow
B. Placenta, liver and spleen, yolk sac, bone marrow
C. Placenta, spleen and lymphatic organs, bone marrow
D. Yolk sac, bone marrow, liver and spleen
E. Yolk sac, liver, spleen and lymphatic organs, bone marrow

[ArchivalUser]

EE

[ArchivalUser]

e.

[ArchivalUser]

ee

[ArchivalUser]

A

[ArchivalUser]

The correct answer is E. By the third week of development, hematopoiesis begins in the blood islands of the yolk sac. Beginning at 1 month of age and continuing until 7 months of age, blood elements are also formed in the liver. Hematopoiesis occurs in the spleen and lymphatic organs between 2 and 4 months, and in the bone marrow after 4 months.

[ArchivalUser]

ee