<p>As embryological development progresses during pregnancy haematopoiesis shifts from the yolk sac and aorta-gonad-mesonephros region (AGM) to the foetal liver and [[Spleen - Anatomy & Physiology|spleen]]. Haematopoietic areas form in the [[Liver - Anatomy & Physiology|liver]] which become the main haematopoietic organ in the body. [[Erythropoiesis|Erythropoiesis]] is the dominant process but some [[Leukopoiesis|leukopoiesis]] occurs so the foetal liver can be considered a [[:Category:Primary Lymphoid Tissue| primary lymphoid organ]].</p> | <p>As embryological development progresses during pregnancy haematopoiesis shifts from the yolk sac and aorta-gonad-mesonephros region (AGM) to the foetal liver and [[Spleen - Anatomy & Physiology|spleen]]. Haematopoietic areas form in the [[Liver - Anatomy & Physiology|liver]] which become the main haematopoietic organ in the body. [[Erythropoiesis|Erythropoiesis]] is the dominant process but some [[Leukopoiesis|leukopoiesis]] occurs so the foetal liver can be considered a [[:Category:Primary Lymphoid Tissue| primary lymphoid organ]].</p> |