Lecture 9- stem cells Flashcards
What two attributes define a stem cell?
The ability to differentiate into many different cell types and its capacity for self renewal.
What is the difference between somatic cells and stem cells?
Somatic cells can only produce two identical daughter cells.
Stem cells can divide into more stem cells and also produce specialised, functional cells.
What are adult stem cells mainly used for in the body?
They are mainly used for cell regeneration of active and stable cells.
What is the process in which stem cells are recruited for cell regeneration?
Cytokines released from the site of injury mobilise stem cells from the bone marrow. The stem cells travel to the site by chemotaxis.
What are embryonic stem cells?
These are stem cells from an embryo (blastocyst) that have not yet specialised to form the fetus. They can be isolated and frozen to be used again later.
What is a pluripotent cell?
A pluripotent stem cell is able to specialise into most body cells, but not all. A stem cell that can specialise into any cell is called Totipotent.
What is an adult stem cell like?
They are normally found in or near their specialised tissue. They are able to specialise into functional cells of their tissue only. They are only found in tissue with high turnover. The adult stem cell reserve decreases with age.
What is an embryonic stem cell like?
It is created from the blastocyst and are able to give rise to any cell in the body, including permanent cells. They can also divide multiple times to make many more cells.
What are placental/umbilical cord stem cells?
These are stem cells derived from the placenta or umbilical cord immediately after birth. These cells are pluripotent.
Where are adult stem cells found in the body?
They are found in mature body tissue-so within the bone marrow.
What kind of molecular circumstances could force a cell back into pluripotency?
Biological stress- low pH environments, as well as physical pressure and bacterial toxins can do this.
How are cancer cells and stem cells similar?
They both have unlimited self-renewal.
