The hematopoietic system Flashcards
From which tissue (gastrulation) does the hematopoietic system arise?
The mesoderm
What are the main functions of the blood?
- Transport of oxygen/carbondioxide, nutrients and hormones
- Thermoregulation
- Body homeostasis (acid-base balance)
The blood stem cells also create the immune cells.
What are the three main types of blood cells?
Erythrocytes (red blood cells)
Platelets (thrombocytes)
Leukocytes (white blood cells)
How many types of stem cells are there in the hematopoietic system and what are their names?
Two: Long term and short term HSCs (hematopoietic stem cells)
How many types of committed progenitor cells does the multipotent progenitors of the hematopoietic system create?
Four
What type of mature cells can a hematopoietic stem cell create?
Erythrocytes, platelets, esinophils, monocytes, dendritic cells, NK cells, B cells and T cells
Why do we need progenitor cells?
- Rapid division is needed
- Division causes DNA damage
- Makes it easier to regulate
What amount of hematopoietic stem cells (HSCs) are quiescent and why?
95%, Quiescence protects the HSCs from the damages that occur with cell division
Where does hematopoiesis start during embryogenesis?
In the yolk sac
What is the migration path for hematopoetic cells during development?
They start in the yolk sac, move to the liver, then to the bone marrow where they stay
At what anatomical position can you find the most hematopoietic stem cells in an adult human?
Vertebra and pelvis
Why do blood cells become larger as we age?
While the cell cycle is arrested when the cells need to fix DNA damage, they continue to increase in size.
What is the most common disease of the hematopoietic system? (often seen in children)
Leukemia
