Sources of stem cells + what they produce Flashcards
When are embryonic stem cells present?
At very early stage of embryo development - are totipotent
What happens after 7 days in embryonic stem cells?
Mass of cells (called blastocyst) forms + cells are now pluripotent
They remain in this state in fetus until birth
When are tissue (adult) stem cells present + where are they found?
Present throughout life from birth, are multipotent but can be artificially triggered to become pluripotent
Found in specific areas, such as bone marrow
Where can tissue (adult) stem cells be harvested from?
Umbilical cords of newborns
What are the advantages of harvesting umbilical cords for adult stem cells?
- Plenty of supply of umbilical cords
- Invasive surgery not needed
- Can be stored for use by umbilical cords owner in future
- Wouldnt be rejected in transplant to owner
Where are plant stem cells sourced + present in?
Meristematic tissue (meristems), which are found wherever growth is occurring in plants
What is the disadvantage of RBCs not having a nucleus and few organelles?
Have short lifespan of 120 days, so need replacing constantly
How many erythrocytes do stem cell colonies in bone marrow produce?
Approx 3 billion erythrocytes per kg of body mass per day - to keep up with demand
How long do neutrophils (WBCs) live for?
Approx 6 hours
How many WBCs do stem cells in bone marrow produce?
1.6 billion per kg per hour - this number increases during infection
What is the name of meristematic tissue between xylem + phloem tissues?
Vascular cambium
What is the role of the stem cells in the vascular cambium region? What potency are they?
They differentiate into the diff cells present in xylem + phloem tissues
In this way, the vascular tissue grows as plant grows
Pluripotent nature of stem cells in meristem continues through plants life
