Blood islands

Definition

Blood islands are clusters of developing blood cells and future blood vessels found within the embryonic yolk sac. They represent the earliest stages of blood vessel and blood cell formation during fetal development.

Related terms

Angiogenesis: The process through which new blood vessels form from pre-existing vessels, essential for growth and healing.

Vasculogenesis: The formation of new blood vessels when there are no pre-existing ones, primarily occurring during embryonic development.

Hematopoiesis: The production of all types of blood cells, including formation, development, and differentiation processes.