Barbaric

Question 1

How many RBCs are lost a day?

Answer 1

• lose 10^11 RBCs a day, but constantly replenished

Question 2

What is life span of specialised cells like?

Answer 2

• short life span and limited proliferative ability

Question 3

How were HSCs identified?

Answer 3

• X-ray exposure stops production of blood cells, mouse dies
• if inject bone marrow from a healthy, immunologically compatible mouse to an irradiated mouse then mouse survives
• looked at spleens of saved mice
• colonies likely originated from single colonies, as created discrete colonies
• the more bone marrow injected, the more colonies

Question 4

What did colonies formed by CFUs contain (HSCs)?

Answer 4

• differentiated blood cells and new colony forming units\then injected CFUs into irradiated mice, this rescued mice too
  Therefore colonies are derived from single cells and contain differentiated blood cells (DIFFERENTIATION) and new CFUs (SELF-RENEWAL) → definition of SCs