adult stem cells Flashcards
Stem cells are different from other cells of the body for 2 reasons
1) Self-renew
2) Differentiate
what is a progenitor cell
Can differentiate into a specific type of cell, but is already more specific than a stem cell and is pushed to differentiate into its “target” cell.
why need to self renew
important for the body to maintain a pool of stem cells to use throughout your life.
what are Embryonic stem cells
found in the blastocyst, a very early stage embryo that has about 50 to 100 cells, they are puripotent
3 roles of adult stem cells
Ð Maintain cell populations
Ð Help you heal
Ð Play a role in ageing
what is cellular homeostasis
The ability to regulate internal conditions, usually by a system of feedback controls
how to adult stem cells help maintain cellular homeostasis
regeneration/replacement
what are Hematopoietic stem cells for
: blood and immune system
Mesenchymal stem cells:
bone, cartilage, fat, muscle,
Epithelial stem cells:
skin, gut, other linings
Neural stem cells:
neurons, glial cells, retinal cells
what is the niche:
Complex microenvironments around the stem cells, made up of many cells, that interact with the environment and the stem cell to decide whether to activate it
what is special about the niche in bone marrow
stores the precursors (the ‘stem cells’) for red blood cells is not ‘dormant’ - we need new red blood cells all the time - so the niche here just protects them
2 types of cells that hematopoetic stem cells specialise
¥ Myeloid (monocytes and macrophages, neutrophils, basophils, eosinophils, erythrocytes, megakaryocytes/platelets, dendritic cells)
¥ Lymphoid (T-cells, B-cells, NK-cells)
where are hematopoetic stem cells
in the bone marrow from very early on in development, as well as in umbilical cord blood and placental tissue
